SERVICE MANUAL
VLT 4252, 4302, 4352, 4152, 4202 VLT 5202, 5252, 5302, 5122, 5152 VLT 6222, 6272, 6352, 6152, 6172 VLT 8252, 8302, 8352, 8152, 8202
Table T able of Contents Contents
iii
Table T able of Contents Contents
iii
Table T able of Contents (continued)
iv
Table of Contents (continued)
v
List of Figures
vi
List of Tables
vii
INTRODUCTION
The purpo se of this m an ual is to provide d etailed technical inform ation and instructions that w ill enab le a q ualified technician to identify faults and perform repairs o n VLT series ad justab le freq ue ncy drives of 125/150 h p to 3 00/350 h p, 38 0 to 4 80 V. It provides the read er w ith a gen eral view of the unit's m ain assem blies and a d escription ofthe internalprocessing.W ith th is in fo rm atio n , te ch n ic ia n s sh o u ld h a ve a b etter u n d ersta n d in g o f th e d rive 's o p e ratio n to a ssist in troubleshooting and repair. This m anualprovides instructions for: V LT 40 00 series 38 0-46 0 V
VLT 4152 VLT 4202 VLT 4252 VLT 4302 VLT 4352
150 hp 200 hp 250 hp 300 hp 350 hp
V LT 60 00 series 38 0-46 0 V
VLT 6152 VLT 6172 VLT 6222 VLT 6272 VLT 6352
VLT 50 00 series 380-46 0 V
150 hp 200 hp 250 hp 300 hp 350 hp
VLT 5122 VLT 5152 VLT 5202 VLT 5252 VLT 5302
125 hp 150 hp 200 hp 250 hp 300 hp
VLT 8000 AQ U A 380-460 V
VLT 8152 VLT 8202 VLT 8252 VLT 8302 VLT 8352
150 hp 200 hp 250 hp 300 hp 350 hp
Th ese m od els are available in C hassis,N E M A 1 o r N EM A 12 enclosures.
VLT ® PRODUCT OVERVIEW V LT 4000 series d rives are d esigned prim arily forthe industrial m arket segm ent.This series ofdrives is cap ab le o foperating only in variab le torque m ode a nd are n orm ally found in co ntrolling fans and pum ps in industrialprocess environm ents. V LT 5000 series drives are fully program m ab le for either constanttorque orvariable torque industrialapplications.They are full-fea tured drives c ap ab le of operating a m yriad of applica tions and inco rporating a w ide variety o fcontrolan d com m unication op tion s. V LT 6000 series d rives are d esign ed for the H V A C m arkets. They operate o nly in variab le torque m ode and includ e sp ecial features an d options w ellsuited forfan an d pum p ap plications w ithin the H V A C m arket. The V LT 800 0 series d rives are d esigned forw ater and w aste w ater m arkets. They can operate in either co nstan t torque orvariable torque w ith lim ited overload capabilities.They include sp ecific features and options w hich m ake them w ellsuited for use on a va riety o f w ater p um p ing an d p rocessing applications.
! DANGER D rives co ntain d an g ero us vo ltag es w he n co nn ec ted to line vo ltag e. O nly a c o m p eten t technician should carry out service.
FOR YOUR SAFETY 1. DO NOT touch electrical parts of drive when AC line is connected. After AC line is disconnected wait at least 15 minutes before touching any components. 2. When repair or inspection is made, AC line must be disconnected. 3. STOP key on control panel does not disconnect AC line. 4. During operation and while programming parameters, motor may start without warning. Activate STOP key when changing data.
! CAUTION W he n p erform ing service, use p rop er E S D p ro ce d ures to p reve nt d am ag e to sen sitive com ponents.
ELECTROSTATIC DISCHARGE (ESD) M an y electronic com ponents w ithin the ad justab le freq uency drive are sensitive to static electricity. V oltages so low that they ca nnot be felt, seen or heard ca n red uce the life, affect p erform ance, or com pletely destroy sensitive e lectronic com ponents.
TOOLS REQUIRED Instruction manual for t he VLT series drive Metric socket set..........................7 - 19mm Socket extensions........................4 in. and 6 in. Torx driver set...............................T10 - T40 Torque wrench..............................6 - 170 in-lbs Needle nose pliers Magnetic sockets Ratchet Screwdrivers.................................standard and Philips
Additional Tools Recommended for Testing Digital volt/ohm meter Analog volt meter Oscilloscope Clamp-on style ammeter Test cable p/n 176F8439 Signal test board p/n 176F8437 V LT is a registered D anfoss trad em ark
Intro-1
Control card cassette
Interface card PCA 2
Power card PCA 3
Control card PCA1
Control input terminals Capacitor bank assembly CBANK1 + PCA9
Capacitor bank cover plate Soft charge card PCA 11
IGBT gate driver card PCA5
DC inductor L1
Fan fuse FU4
Input terminal mounting plate assembly
AC input bus bar
Main AC power input terminals TB1
SCR/Diode module SCR1, 2, 3 Fan transformer TR1
IGBT module IGBT1
Fan assembly F1 + C1 +CBL11
Current sensor L1, L2, L3
IGBT output bus bar Output motor terminals TB2
E xplod ed V iew (12 5 - 20 0 h p) V LT 4 15 2, 42 02 ; V LT 5 12 2, 51 52 ; V LT 6 15 2, 61 72 ; V LT 8 15 2, 82 02
Intro-2
V LT is a registered D anfoss trad em ark
Control card cassette
Interface card PCA2 Power card PCA3
Control card PCA1
Control input terminals
Upper capacitor bank cover plate
Capacitor bank assembly CBANK1 + PCA9
Lower capacitor bank cover plate
Soft charge card PCA11 IGBT gate driver card PCA5
DC inductor L1
Capacitor bank assembly CBANK2 + PCA10 Input terminal mounting plate assembly
Fan fuse FU4
AC input bus bar
Soft charge resistor assy R1 + CBL26
Main AC power input terminals TB1 Fan transformer TR1
IGBT snubber C2, C3, C4, C5, C6, C7 IGBT module IGBT1, 2
SCR/Diode module SCR1, 2, 3
Fan assembly F1 + C1 + CBL11 IGBT output bus bar
Current sensor L1, L2, L3
Output motor terminals TB2
E xp lod ed V iew V LT 4 25 2, 43 02 , 43 52 ; V LT 5 20 2, 52 52 , 53 02 ; V LT 6 22 2, 62 72 , 63 52 ; V LT 8 25 2, 83 02 , 83 52 V LT is a registered D anfoss trad em ark
Intro-3
R atings T ab le
Compact, Mains supply 3 x 380-500 V VLT type
5122
5152
5202
5252
5302
Normal overload current ratings (110 %): Output current
IVLT,Nominal [A] (380-440 V) IVLT, MAX (60 s) [A] (380-440 V) IVLT,Nominal [A] (441-500 V) IVLT, MAX (60 s) [A] (441-500 V)
212 233 190 209
260 286 240 264
315 347 302 332
395 434 361 397
480 528 443 487
Output
SVLT,Nominal [kVA] (400 V) SVLT,Nominal [kVA] (460 V) SVLT,Nominal [kVA] (500 V)
147 151 165
180 191 208
218 241 262
274 288 313
333 353 384
Typical shaft output
[kW] (400 V) [HP] (460 V) [kW] (500 V)
110 150 132
132 200 160
160 250 200
200 300 250
250 350 315
Output current
IVLT,Nominal [A] (380-440 V) IVLT, MAX (60 s) [A] (380-440 V) IVLT,Nominal [A] (441-500 V) IVLT, MAX (60 s) [A] (441-500 V)
177 266 160 240
212 318 190 285
260 390 240 360
315 473 302 453
395 593 361 542
Output
SVLT,Nominal [kVA] (400 V) SVLT,Nominal [kVA] (460 V) SVLT,Nominal [kVA] (500 V)
123 127 139
147 151 165
180 191 208
218 241 262
274 288 313
Typical shaft output
[kW] (400 V) [HP] (460 V) [kW] (500 V)
90 125 110
110 150 132
132 200 160
160 250 200
200 300 250
2619 2206
3309 2619
4163 3309
4977 4163
6107 4977
High overload torque (160 %):
Power loss Normal overload [W] Power loss High overload [W] Limits and Ranges Warning Voltage Low Alarm Voltage Low
DC Bus V DC Bus V
423 402
423 402
423 402
423 402
423 402
Warning Voltage High Alarm Voltage High
DC Bus V DC Bus V
801 855
801 855
801 855
801 855
801 855
Brake On Voltage Brake On Voltage (Full Duty Cycle)
DC Bus V DC Bus V
795 815
795 815
795 815
795 815
795 815
SMPS Start Voltage SMPS Stop Voltage
DC Bus V DC Bus V
360 330
360 330
360 330
360 330
360 330
Overcurrent Warning Overcurrent Alarm (1.5 sec delay)
IVLT Out IVLT Out
327 327
392 392
480 480
582 582
730 730
Earth Fault Alarm
IVLT Out
80
95
120
151
180
Heatsink Over Temperature
Degrees C
75
80
95
95
105
DC Bus Ripple Vac DC Bus Ripple Vac
50 50
50 50
50 50
50 50
50 50
Mains Phase Warning Mains Phase Alarm
(5 sec delay) (25 sec delay)
Fan On Low Speed Temperature Fan On High Sped Temperature Fan Off Temperature
Degrees C Degrees C Degrees C
45 60 <30
45 60 <30
45 60 <30
45 60 <30
45 60 <30
Fan Voltage Low Speed Fan Voltage High Speed
Fan Vac Fan Vac
200 230
200 230
200 230
200 230
200 230
Intro-4
V LT is a registered D anfoss trad em ark
SECTION 1 OPERATOR INTERFACE AND DRIVE CONTROL
INTRODUCTION VLT drives are designed w ith self-diagnostic circuitry to iso late fau lt co nditions and activate d isp lay m essages w hich greatly sim plify troubleshooting an d service.The operating status o f the drive is d isp layed in real-tim e. Virtually every com m and given to the drive results in som e indication on the localco ntrol panel(LC P )disp lay.Faultlogs are m aintained w ithin the drive for fault history. The drive m onitors supply an d outputvoltag es along w ith the operationalco ndition of the m otor and load . W hen the d rive issues a w arning oralarm ,itcann otbe assum ed thatthe fault lies w ithin the drive itself. In fact, for m ost service calls, the fault condition w illbe found outside of the drive. M ost ofthe w arning s and alarm s tha tthe d rive d isplays a re g enerated by response to fau lts outside o f the drive. This service m an ual provides techniques and testprocedures to help isolate a fault co ndition w hether in the d rive o r elsew here.
O n the V LT 40 00 /60 00 /80 00 series d rives, the [D IS P LA Y/ S TA TU S ] key is identified as the [D IS P LA Y M O D E] key and op erates in the sam e m anner described .
Fam iliarity w ith the inform ation provided on the disp lay is im portan t.A dditionaldiag nostic d ata can b e accessed easily throu gh the L C P.
P ressing the [D IS P LA Y /S TA TU S ] key on the keypad toggles betw een the defaultsetting and the program m ab le three m eter disp lay in line 1.
Normal Display In norm aloperationalm ode after start up, the top line o f the disp lay (line 1)identifies the value disp layed in line 2.The large disp lay (line 2)show s a value, in this c ase the drive output in hertz. The setup num ber and direction of m otor rotation is also sh ow n.The bottom line (line 4)is the status line.This line disp lays the current op erational status o f the d rive. The illustration below indicates that the drive is running at 40 H Z output.
Line 1 Line 2
FREQUENCY
40. 0Hz
SETUP
1
Line 1
66% 82. 1%
19. 4A
40. 0Hz
SETUP
1
RUNNI NG To identify the 3 m eters d isp layed in line 1 ,press and ho ld the [D IS P LA Y/STA TU S]key.The identity o f the m eter is d isp layed w hile the ke y is pressed.
Line 3 Line 4
RUNNI NG
P ressing the up [+ ] or dow n [-] keys on the keypad in this m od e chang es the d ata sho w n in line 2. Thirty-one different diagnostic values are identified (in line 1)and disp layed (in line 2) by scrolling through the disp lay data. Setpoints, feed back, operationalhours,digitalan d analog inputstatus,relay o utputstatus,and m an y other system functions are identified and theirvalues show n in real-tim e.
REF% TORQ% CURR. A
40. 0Hz
SETUP
1
RUNNI NG
Th e values displayed in lines 1 and 2 can be p rog ram m ed from a list of options. S ee program m ing in the o perator's m anualfordetails. 1-1 V LT is a reg istered D an foss trad em ark
Status Display
Factory Default Display Settings
The status line o fthe d isp lay (line 4 )reports inputs com m anding drive operations.
A ny ofthe values show n by scrolling through the d isp lay in line 2 are also available to disp lay in the three m eter disp lays on line 1. S ee the drive instruction m an ual for procedures on prog ram m ing d rive param eters.
The V LT 5000 series drives have a slightly differentstatus disp lay form atthan the VLT 40 00 /60 00/80 00 series d rives.
Factory defaultvalues and associated param eters forVLT 5000 series d rives are show n b elow .
FREQUENCY
60. 0Hz
SETUP
1
AUTO REM. RUNNI NG HAND LOCAL STOP RAMPI NG OFF J OGGI NG .. .. STAND BY 1
2
3
1. Fo rthe V LT 400 0/6000 /80 00 ,the firststatus display ind icates w here the startco m m and co m es from ,au tom atic o r hand start. In auto start,the drive looks for a rem ote startsignal.In hand start,the drive receives a localinput through the [H A N D S TA R T]key. 2. Th e second status d isplay ind icates w here the speed com m and com es from ,rem ote or local. Lo calrespond s to the [+ ]and [-]keys o n the keypad .R em ote is tied to auto startan d looks for an externalreference signal. 3. The third display show s the operationalstatus of the d rive:running,stopped ,stan d by,ram ping, and so on. For the VLT 5000 series, the status d isp lay on line 4 is not segm en ted .It show s the o perationalstatus ofthe d rive w ith the localor rem ote indication as p artofthe disp lay title. Tab les 1-1 an d 1-2 list the disp lays show n in the status line and define their m eaning . B ecause the V LT 500 0 series an d V LT 4 000/6000/8000 series h ave differen t disp lay status indications, the d efinitions appearin separate tab les. Fam iliarity w ith the status disp lay p rovides inform ation regarding the o perationalm ode o fthe d rive.The status line d isp lays are not program m able.
1-2
V LT is a reg istered D anfoss trad em ark
Line 1 disp lays:
Line 2 disp lay:
010 R eference (% ) 011 M otor current(A ) 012 P ow er (kW )
00 9 F requency (H z)
Factory defaultvalues and associated param eters forVLT 4000 /60 00 /80 00 series d rives are show n b elow . Line 1 disp lays:
Line 2 disp lay:
008 R eference (% ) 009 M otorcurrent(A ) 010 P ow er(hp)
00 7 F requency (H z)
Tab le 1-1 defines the status line disp lay show n in V LT 5000 series drives. Tab le 1 -1. V LT 5000 S eries S tatus D efinitions
DISPLAY
DESCRIPTION
Automatic motor adaptation enabled in parameter 107, Automatic AUTO MOTOR Motor Adaptation, AMA and drive performing adaptation function. ADAPT BRAKE CHECK OK Brake check function is completed and brake resistor and transistor tested successfully. BRAKING Drive brake is functioning and motor is being slowed. BRAKING MAX Drive brake functioning at maximum. Drive brakes to its maximum when running 100% duty cycle. CATCH UP Drive output frequency increased by percentage value selected in parameter 219, Catch up/Slow down Value. CONTROL READY Condition causing UNIT NOT READY status has been rectified and drive is ready for operation. CURRENT HIGH Warning of drive output current higher than value set in parameter 224, Warning: High Current . Drive will continue to operate. CURRENT LOW Warning of drive output current lower than value set in parameter 223, Warning: Low Current . Drive will continue to operate. EXCEPTIONS Control microprocessor stopped for unknown cause and drive not XXXX operating. Cause may be due to noise on the power line, motor leads or control wires. FEEDBACK HIGH Warning of a feedback signal higher than value set in parameter 228, Warning: High Feedback . Drive will continue to operate. FEEDBACK LOW Warning of a feedback signal lower than value set in parameter 227, Warning: Low Feedback . Drive will continue to operate. FREEZE OUTPUT Drive output frequency frozen at current rate via digital input or serial communication. FREQUENCY Warning of drive frequency higher than value set in parameter 226, HIGH Warning: High Frequency . Drive will continue to operate. FREQUENCY LOW Warning of drive frequency lower than value set in parameter 225, Warning: Low Frequency . Drive will continue to operate. LOCAL/DC STOP Local control selected and drive stopped via a DC braking signal on terminal 27 or serial communication. LOCAL/LCP STOP Local control selected and drive is stopped via control panel. Coast signal on terminal 27 high. LOCAL/QSTOP Local control selected and drive stopped via a quick-stop signal on terminal 27 or serial communication. LOCAL/RAMPING Local control selected and motor speed and drive output frequency is changing. LOCAL/RUN JOG
LOCAL/RUN OK LOCAL/STOP LOCAL/UNIT READY
Local control selected and drive is running at a fixed frequency set in parameter 213, Jog Frequency via digital input or serial communication. Local control selected and motor is running and speed corresponds to reference. Local control selected and drive stopped via control panel, digital input or serial communication. Local control selected and 0 V on terminal 27.
V LT is a reg istered D an foss trad em ark
1-3
Tab le 1 -1. V LT 5000 S eries S tatus D efinitions (co ntinued )
DISPLAY OFF1 OFF2 OFF3 OVER VOLTAGE CONTROL QUICK DISCHARGE OK REM/BUS JOG1 REM/BUS JOG2 REM/DC STOP REM/LCP STOP
REM/QSTOP REM/RAMPING REM/RUN JOG
REM/RUN OK REM/STOP REM/UNIT READY SLOW DOWN STAND BY START FORW./REV START INHIBIT
UNIT NOT READY
1-4
DESCRIPTION Stop command (Ramp Down) received via serial communication, and Fieldbus selected in parameter 512. Stop command (Coast) received via serial communication, and Fieldbus selected in parameter 512. Stop command (Q Stop) received via serial communication, and Fieldbus selected in parameter 512. Parameter 400, Overvoltage Control , enabled. Drive is attempting to avoid a trip from overvoltage by extending decel ramp time. Quick discharge function has been completed successfully. Remote control selected and Fieldbus selected in parameter 512. Jog 1 command has been given via serial communication. Remote control selected and Fieldbus selected in parameter 512. Jog 2 command has been given via serial communication. Remote control selected and drive stopped via a DC stop signal on a digital input or serial communication. Remote control selected and drive is stopped via control panel. Coast signal on terminal 27 high. Start command via remote digital input or serial communication is overridden. Remote control selected and drive stopped via a quick-stop signal on terminal 27 or serial communication. Remote control selected and motor speed and drive output frequency is changing. Remote control selected and drive is running at a fixed frequency set in parameter 213, Jog Frequency via digital input or serial communication. Remote control selected and motor is running and speed corresponds to reference. Remote control selected and drive stopped via control panel, digital input or serial communication. Remote control selected and 0 V on terminal 27. Drive output frequency reduced by percentage value selected in parameter 219, Catch up/Slow down Value. Drive will start when a start signal received via digital input or serial communication. Input on digital inputs and parameter data are in conflict. OFF1, OFF2, OFF3 condition has been rectified. Drive cannot start until OFF1 bit is toggled (OFF1 set from 1 to 0 then to 1). Fieldbus selected in parameter 512. Drive not ready for operation because of a trip or because OFF1, OFF2 or OFF3 is a logic ‘0.’ (Only on units with external 24 VDC supply.)
V LT is a reg istered D anfoss trad em ark
Tab le 1-2 defines the status line display show n in V LT 400 0/ 6000/8000 series drives. Tab le 1-2. V LT 4000/6000/8000 S eries S tatus D efinitions DISPLAY
AUTO HAND OFF
REM. LOCAL
AMA RUN AMA STOP AUTO RAMP CTR.READY DC STOP FRZ.OUT FRZ.REQ JOG JOG REQ. NOT READY RAMPING RUN REQ. RUNNING SLEEP SLEEP.BST STANDBY START
START DEL START IN. STOP UN.READY XXXX
DESCRIPTION CONTROL POINT Drive in Auto mode, which means that Run/Stop control is carried out remotely via input control terminals and/or serial communication. Drive in Hand mode, which means that Run/Stop control is carried out via keys on the keypad. OFF/STOP activated either by means of keypad or by digital input terminals. REFERENCE LOCATION REMOTE selected, which means reference is set via input control terminals or serial communication. LOCAL selected, which means reference is set with [+] and [-] keys on keypad. DRIVE STATUS Automatic motor adaptation enabled in parameter 107, Automatic Motor Adaptation, AMA and drive performing adaptation function. Automatic motor adaptation completed. Drive is now ready for operation after Reset enabled. Motor may start after drive reset. Parameter 208, Automatic Ramp, enabled. Drive is attempting to avoid a trip from overvoltage by extending decel ramp time. This status only active when a Profibus option card is installed. DC brake enabled in parameters 114 through 116. Drive output frequency frozen at fixed rate from input command. Start command to run at current frequency given but motor will not start until a Run Permission signal is received via a digital input. Jog enabled via digital input or serial communication. Drive is running at a fixed frequency set in parameter 209, Jog Frequency. Start command to run at jog frequency given but motor will not start until a Run Permission signal is received via a digital input. Drive not ready for operation because of a trip or because OFF1, OFF2 or OFF3 is a logic ‘0.’ Motor speed and drive output frequency is changing. Start command given but motor will not start until a Run Permission signal is received via digital input. Motor running and speed corresponds to reference. Parameter 403, Sleep Mode Timer, enabled. Motor stopped in sleep mode. It can restart automatically. Sleep boost function in parameter 406, Boost Setpoint, enabled. Drive is ramping up to boost setpoint. Drive able to start motor when a start command is received. Reversing and start on terminal 19, parameter 303, Digital Inputs, and Start on terminal 18, parameter 302, Digital Inputs, are both enabled. Motor will remain stopped until either signal becomes logic ‘0.’ Start delay time programmed in parameter 111, Start Delay . When delay time expires, drive will start and ramp up to reference frequency. This status only displayed if parameter 599, Profidrive [1] selected and OFF2 or OFF3 is a logic ‘0.’ Motor stopped via a stop signal from serial communication. Unit ready for operation but digital input terminal 27 is logic ‘0’ and/or a Coasting Command received via serial communication. Control microprocessor stopped for unknown cause and drive not operating. Cause may be noise on the power line, motor leads or control wires. V LT is a reg istered D an foss trad em ark
1-5
WARNINGS AND ALARMS
Warnings
W hen the drive fault circuitry d etects a fault condition, or a pending fault,a w arning oralarm is issued.A flashing disp lay on the LC P ind icates a n alarm or w arning co nd ition and the associated num ber code on line 2 . A w arning m ay precede an alarm .Tab le 1-3, Fault M essages ,defines w hether or no t a w arning precedes an alarm and w hetherthe d rive susp ends operations (trips).
D uring a w arning, the d rive w illrem ain operational, although the w arning w illflash for as long as the condition exists. The d rive m ay, ho w eve r, take a ction to red uc e the w arning co ndition.Forexam ple, ifthe w arning disp layed w ere Torque Limit (W arning 12), the drive w ould be red ucing speed to co m pensate for the o ver curren t co nd ition.In som e cases,if the condition is not co rrec ted or grow s w orse, an alarm cond ition w ould be activated and the drive o utput to the m otor term inated.Line 1 identifies the w arning in plain language and line 2 identifies the w arning num ber.
Alarms A n alarm causes the d rive to trip (susp en d operation). The drive has three trip co nditions w hich are disp layed on line 1:
MAI NS PHASE LOSS TRI P ( RESET)
ALARM: 12
WARN. 4
SETUP
1
SETUP
1
TORQUE LI MI T
TR IP (A U TO R ES TA R T) m eans the d rive is prog ram m ed to restartautom atically afterthe faultis rem oved.The num ber of au tom atic reset attem pts m ay b e continuo us or lim ited to a prog ram m ed num ber of attem pts. Th is w illchang e to TR IP (R ES ET)ifthe selected num ber ofau tom atic reset attem pts is exceeded. TR IP (R ES E T) requires resetting the d rive prior to operation after a fault is cleared. The d rive can be reset m anually by pressing the reset key on the keyp ad, a d igital input, or a serialbus com m and.Fo rVLT 5000 series drives,the stop and reset key are the sam e. If the stop/rest key is used to reset the d rive, the start key m ust be p ressed to initiate a run co m m and in either localor rem ote. TR IP LO C K (D IS C > M A IN S ) requires that the m ain A C inp ut pow er to the drive m ust be d isconn ected long enou gh forthe display to go b lank.The faultco ndition m ustbe rem oved and pow er reapplied .Follow ing pow er up,the fau ltindication w ill ch ange to TR IP (R ES ET)an d allow form an ual,digital,orserial bus reset. Line 2 displays a larm and the asso ciated nu m ber w hile line 3 identifies the alarm in plain language.
SERVICE FUNCTIONS S ervice inform ation forthe drive can be show n on disp lay lines 3 and 4.Tw enty-six differen titem s can b e accessed.Included in the data are co un ters thattab ulate operating hours,pow er ups and trips; faultlogs thatstore drive status values p resent at the 20 m ostrecentevents thatstopped the drive;and drive na m ep late d ata. The service inform ation is acce ssed b y disp laying item s in the d rive's 600s param eter group.
FREQUENCY
0. 0Hz Line 3 Line 4
SETUP
1
604 OVER TEMP' S 0003
P aram eter setting s are displayed by pressing the [M EN U ]key on the LC P keypad.
U se the [+ ] and [-] keys o n the LC P keyp ad to scrollthrough p aram eters.
S ee the operator's m anualfordetailed inform ation on accessing and displaying param eters and fordescriptions and procedures forservice inform ation availab le in the 600s p aram eter group.
1-6
V LT is a reg istered D anfoss trad em ark
FAULT MESSAGE TABLE Table 1 -3 lists the d rive’ s faultm essages and indicates w hether a w arning,alarm ,ora trip-locks occurs.A ftera trip-lock, input pow er m ust be rem oved, the cause of the fault co rrected , an d the inp utpow er restored to reset the drive.
W herever an “ X”is placed un der both w arning an d alarm , a w arning preced es the alarm . A n alarm alw ays preced es, or sim ultan eously accom pan ies, a trip-lock. W hich faults are rep orted m ay vary dep en ding on the particular drive m odel.
Tab le 1-3. F au lt M essages
No. 1 2 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 22 29 30 31 32 34 35 37 39 40 41 42 60 61 62 63 64 65 66 67 68 69 99
Description Warning Under 10 volts (10 VOLT LOW) X Live zero fault (LIVE ZERO ERROR) X Input phase imbalance (MAINS IMBALANCE) X Voltage warning high (DC LINK VOLTAGE HIGH) X Voltage warning low (DC LINK VOLTAGE LOW) X Overvoltage (DC LINK OVERVOLT) X Undervoltage (DC LINK UNDERVOLT) X Inverter overloaded (INVERTER TIME) X Motor overloaded (MOTOR TIME) X Motor temp high (MOTOR THERMISTOR) X Current limit reached (CURRENT LIMIT) X Overcurrent (OVERCURRENT) Ground fault detected (EARTH FAULT) Switch mode power fault (SWITCH MODE FAULT) Short circuit (CURR.SHORT CIRCUIT) Serial communication timeout (STD BUSTIMEOUT) X HP field bus timeout (HPFB TIMEOUT) X Fault in EEPROM on power card (EE ERROR POWER) X Fault in EEPROM on control card (EE ERROR CONTROL) X Auto motor adaptation fault (AMA FAULT) Heat-sink temperature high (HEAT SINK OVERTEMP.) Motor phase U missing (MISSING MOT.PHASE U) Motor phase V missing (MISSING MOT.PHASE V) Motor phase Wmissing (MISSING MOT.PHASE W) HPFB communication fault (HPFB COMM. FAULT) X Out of frequency range (OUT FREQ RNG/ROT LIM) X Inverter fault (GATE DRIVE FAULT) Check parameters 104 and 106 (CHECK P.104 & P.106) X Check parameters 103 and 105 (CHECK P.103 & P.106) X Motor too large (MOTOR TOO BIG) X Motor too small (MOTOR TOO SMALL) X Safety stop (EXTERNAL FAULT) Output frequency low (FOUT < FLOW) X Output frequency high (FOUT > FHIGH) X Output current low (I MOTOR < I LOW) X Output current high (I MOTOR > I HIGH) X Feedback low (FEEDBACK < FDB LOW) X Feedback high (FEEDBACK > FDB HIGH) X Reference low (REF. < REF. LOW) X Reference high (REF. > REF. HIGH) X Temperature auto derate (TEMP.AUTO DERATE) X Unknown fault (UNKNOWNALARM)
Alarm X X
X X X X X X X X X X X X
X X X X X X X
Trip Locked
X
X X X X
X
X
X
X
X
X
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1-7
DRIVE INPUTS AND OUTPUTS
Input Signals
The drive operates by receiving control signals. A building The drive can receive two types of remote input signals, digital management system, remote sensors, a speed command and analog. Digital inputs are wired to terminals 16, 17, 18, from associated equipment, or a PLC (programmable logic 19, 20 (common), 27, 29, 32, and 33. Analog inputs are wired controller) are examples of possible controllers. Inputs get to to terminals 53, 54, and 55 (common), or terminal 60. the drive in three possible ways. One way is through the keypad Analog signals can be either voltage (0 to +10 VDC) connected on the front of the drive when operating in local (hand) mode. to terminals 53 and 54, or current (0 to 20 mA or 4 to 20 mA) These include start, stop, reset and speed reference. Another connected to terminal 60. Analog signals can be varied like control source is through serial communication from a serial dialing a rheostat up and down. The drive can be programmed bus. A serial communication protocol supplies commands and to increase or decrease output in relation to the amount of references to the drive and reads status and data from the current or voltage. For example, a sensor or externa l controller drive. The serial bus connects to the drive through the RSmay supply a variable current or voltage. The drive output, in 485 serial port. Use of serial communication may require turn, regulates the speed of the motor connected to the drive installation of a corresponding option card. in response to the analog signal. The third way input signals get to the drive is through wiring Digital signals are a simple binary 0 or 1 which, in effect, act as connected to the drive control terminals. The drive control a switch. Digital signals are controlled by a 0 to 24 VDC signal. terminals are located below the LCP keypad (see Figure 1-1). A voltage signal lower than 5 VDC is a logic 0. A voltage higher than 10 VDC is a logic 1. Zero is open, one is close. Digital inputs to the drive are switched commands such as start, stop, reverse, coast, reset, and so on. (Do not confuse these digital inputs with serial communication formats where digital bytes are grouped into communication words and protocols.) The RS-485 serial communication connector is wired to terminals (+) 68 and (-) 69. Terminal 61 is common and may be used for terminating shields only when the control cable is run between VLT drives, not between drives and other devices. See Grounding Shielded Cables in this section for correct methods for terminating shielded control cable.
Output Signals
Figure 1-1. Control Terminals
The drive also produces output signals that are carried through either the RS-485 serial bus or terminals 42 and 45. Output terminals 42 and 45 operate in the same manner as the inputs. These terminals can be programmed for either a variable analog signal in mA or a digital signal (0 or 1) in 24 VDC. In addition, the terminals can provide a pulse reference of 0 to 32,000 pulses. Output analog signals generally indicate the drive frequency, current, torque and so on to an external controller or system. Digital outputs can be used to open or close a damper, for example, or send a start or stop command to auxiliary equipment. Additional terminals are 01, 02, and 03, which are a Form C relay output. Terminals 04 and 05 are a 1 A low voltage relay output. Terminals 12 and 13 provide 24 VDC low voltage power, often used to supply power to the digital input terminals (16-33). Those terminals must be supplied with power from either terminal 12 or 13, or from a customer supplied external 24 VDC power source. Improperly connected control wiring is a common service issue for a motor not operating or the drive not responding to a remote input.
1-8
VLT is a registered Danfoss trademark
Control Terminals
Control Terminal Functions
C on trol term inals m ust be prog ram m ed . Each term inalhas sp ecific functions itis capab le o fperform ing an d a num bered param eter asso ciated w ith it.S ee Tab le 1-4 below .The setting selected in the param eter enab les the function ofthe term inal.
The follow ing describes the functions o fthe controlterm inals. M any o fthese term inals have m ultiple fun ctions determ ined by p aram eter settings. S ee Figure 1 -2, Control Terminals
Itis im portantto confirm that the co ntrolterm inalis p rogram m ed for the c orrectfunction.
Elect rical Diagram .
Term inalN o.
Function
01,02,03
Form C relay output.M axim um 240 VAC ,2 A. M inim um 24 VD C , 10 m A or 24 VAC , 100 m A . C an be used for ind icating status and w arning s.P hysically located on pow er card.
U se the [+ ] and [-] keys o n the LC P keyp ad to scrollthroug h p aram eters.The 30 0s param eter group is used to setco ntrolterm inalvalues.
0 4,0 5
3 0 V A C , 4 2.5 V D C , 1 A relay o utp ut. C an be used forind icating status and w arning s.
S ee the o perator’ s m an ualfordetails on chan ging param eters and the functions available for each controlterm inal.
12,13
Vo ltage supp ly to digitalinputs and external transd ucers.Fo rthe 24 V D C to be used for digitalinputs, sw itch 4 on the controlcard m ust be closed (O N po sition).The m axim um output currentis 200 m A .
16 - 33
P rogram m able digitalinpu ts for controlling the drive.R = 2 kohm .Less than 5 V = log ic 0 (o p en ). G rea ter tha n 10 V = lo gic 1 (closed).
20
C om m on fordigitalinputs.
39
C o m m on foranalog and d igitaloutp uts.
42 ,45
A nalog and d igitaloutputs forindicating values such as freq uen cy, reference, cu rren t an d torque.The analog signalis 0 to 20 m A ,or4 to 20 m A ata m axim um of500 Ω. The digital signalis 24 VD C at a m inim um of 60 0 Ω.
50
10 VD C , 17 m A m axim um analog supply voltage forpotentiom eterortherm istor.
5 3,5 4
0 to 1 0 V D C vo ltag e inp ut,R = 1 0 k Ω. U sed fo r referen ce o r fee d b ack sig nals. A therm istor can b e co nn ected here.
P aram eter settings are displayed by p ressing the [M EN U ]key on the LC P keypad.
In addition,the digitalinputterm inalm ust be receiving a signal. C onfirm that the controlan d pow er sources are w ired to the term inal. Then ch eck the signal. S ign als can b e checked in tw o w ays. R elay status can be selected in the display using the [D IS P LA Y M O D E ] key as discu ssed previously,ora vo ltm eter m ay b e used to check for voltage atthe controlterm inal.S ee p rocedure d etails atInput Term inalTest in S ection 5. In sum m ary,forproper drive functioning,the drive inputco ntrol term inals m ust be: 1. w ired prop erly 2 . p ow ered 3. prog ram m ed correctly forthe intended function 4. receiving a sign al
Tab le 1 -4. C on trolTerm ina ls an d A ssociated P aram eter
Term 16 17 18 19 27 29 32 33 53 54 60 42 45 1-3 4-5 Para 300 301 302 303 304 305 306 307 308 311 314 319 321 323 326 C on trol term inals m ust be prog ram m ed . Each term inalhas sp ecific fun ction s it is cap ab le of perform ing and a num bered pa ram eter associated w ith it. The setting selected in the param eter enab les the fun ction of the term inal. S ee the O perator's M anua lfor details.
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1-9
55
Common for analog inputs. This common is isolated from the common of all other power supplies. If, for example, the drive’s 24 VDC power supply is used to power an external transducer, which provides an analog input signal, terminal 55 must be wired to terminal 39.
60
Programmable 0 to 20 mA or 4 to 20 mA, analog current input, R = 188 Ω. Used for reference or feedback signals.
61
RS-485 common.
68, 69
RS-485 interface and serial communication.
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Grounding Shielded Cables Itis recom m ended thatshielded co ntrolcables b e conn ected w ith cable clam ps at both ends to the m etal cabnet of the drive.Figure 1-3 show s g round cabling foroptim alresults.
Correct grounding C on trol cab les a nd cab les for serial co m m un ication m ust be fitted w ith c ab le clam ps at both e nd s to en sure the b est po ssible elec trica l connec tion.
Incorrect grounding D o no t use tw isted cable e nd s (pigtails) since these inc rea se shield im ped ance at high freq uencies.
Ground potential protection W hen the g rou nd po tential be tw een the d rive and the P LC or other interface d evice is d ifferen t, electricalnoise m ay occur that ca n d isturb the entire system . This can be reso lved by fitting an eq ualizing cable next to the controlcable. M inim um cable crosssection is 8 A W G .
50/60 Hz ground loops W hen using very long con trolcab les, 50 /60 H z ground loo ps m ay occur that can d isturb the en tire system . This can b e resolved by co nnecting on e en d of the shield w ith a 10 0 n F cap acitor and keep ing the lead short.
Serial communication control cables Lo w freq uency no ise currents betw een d rives can be elim inated by co nn ecting on e end ofthe shielded cable to d rive term ina l61. This term inal co nnects to groun d through a n internalR C link. It is recom m en ded to u se tw isted -pair cables to reduce the differential m od e interference b etw een con du tors.
Figure 1-3. G roun d ing S hield ed C ab les
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1-11
SECTION 2 INTERNAL DRIVE OPERATION
GENERAL
To provide an overview, the main drive components will be This section is intended to provide an operational over view of grouped into three categories consisting of the control logic the drive’s main assemblies and circuitry. With this information, section, logic to power interface, and power section. In the a repair technician should have a better unders tanding of the sequence of operation description, these three sections will be covered in greater detail while describing how power and drive's operation and aid in the troubleshooting process. control signals move throughout the drive. The VLT series drives covered in this manual are very similar in design and construction. For the purpose of troubleshooting, two main differences exist. First, the control card and LCP for Logic Section the VLT 5000 series differs from that of the other three series. The control card contains most of the logic section (see Figure Second, the power section is rated differently in a constant 2-2). The primary logic element of the control card is a torque drive (VLT 5000) versus a variable torque drive. The microprocessor, which supervises and controls all functions power section of a 125 hp VLT 5000 series is similar to that of of drive operation. In addition, separate PROMs contain the a 150 hp in the other three series , and so on. parameters to provide the user with programmable options. These parameters are programmed to enable the drive to meet specific application requirements. This data is then stored in an EEPROM which provides security during power-down and also allows the flexibility to change the operational characteristics of the drive.
DESCRIPTION OF OPERATION
An adjustable frequency drive is an electronic controller that A custom integrated circuit generates a pulse width modulation supplies a regulated amount of AC power to a standard three (PWM) waveform which is then sent to the interface cir cuitry phase induction motor in order to control the speed of the located on the power card. motor. By supplying variable frequency and voltage to the motor, the drive controls the motor speed, or maintains a constant speed as the load on the motor changes. The drive can also stop and start a motor without the mechanical stress associated with a line start. Local
Control Panel
In its basic form, the drive can be divided into four main sections: rectifier, intermediate circuit, inverter, and control and regulation (see Figure 2-1).
M I C R O P R O C E S S O R
DATA
ADRESS
RAM
PROM
E E P R O M
VVC
POWER
INTERMEDIATE CIRCUIT
INVERTER SECTION (IGBTs)
ANALOG INPUTS
A 2
CONTROL
RECTIFIER (SCR/DIODES)
D
PLUS
POWER FEEDBACK DIGITAL
MOTOR COILS
INPUTS 1
L1
U
L2
V
L3
W
D
ANALOG OUTPUTS
A 1
DIGITAL CHANNEL 1
SOFT CHARGE CIRCUITRY
RELAY
VLT is a registered Danfoss trademark
2-1
The P W M w aveform is created using an im proved control schem e called V V C plus , a further developm ent of the earlier V V C (V oltag e V ector C ontrol) system . V V C plus p rovides a variab le freq uency and voltag e to the m otor w hich m atches the req uirem ents ofthe m otor.The dynam ic resp onse ofthe system chan ges to m eet the variab le req uirem ents of the load . A nother part of the logic section is the local control panel (LC P ). This is a rem ovab le ke ypad /display m oun ted on the frontofthe d rive.The keypad provides the interfac e b etw ee n the drive's internaldigitallogic and the operator. A ll the drive's program m ab le p aram eter settings can b e up load ed into the EE P R O M of the LC P.This fun ction is useful for m aintaining a back up drive profile and param eter set. It ca n also b e u se d , thro ug h its d o w nlo ad functio n, in program m ing otherdrives o rto restore a program to a rep aired un it. The LC P is rem ovab le d uring operation to p revent un desired program ch anges. W ith the ad dition o f a rem ote m ounting kit, the LC P can be m ou nted in a rem ote location of up to ten fee t aw ay. C ontrolterm inals,w ith program m ab le functions,are provided for inp ut co m m an ds such as run ,stop,forw ard,reverse and sp eed reference. A dditionaloutputterm inals are p rovided to supply signals to run peripheraldevice s o rform onitoring an d reporting status. The co ntrolcard logic is cap ab le ofco m m unicating via serial link w ith outside d evices such as p ersona l co m puters or program m ab le logic controllers (P LC ). The co ntrolcard also provides tw o voltag e supplies for use from the controlterm inals.The 2 4 V D C is used for sw itch ing functions su ch as start, stop an d forw ard/reve rse. The 2 4 VD C sup ply is also cap ab le o fsup plying 200 m a ofpow er,part of w hich m ay be use d to p ow er externalencoders or other devices.A 10 V D C sup ply rated at 17m a is also availab le for use w ith sp eed reference circuitry. The analog and digitaloutputsignals are p ow ered throug h an internaldrive su pply.The three p ow er supplies are iso lated from one a nother to elim inate g round loop co nditions in the controlinputcircuitry. A single pole low voltag e relay on the co ntrolca rd ac tivates externaldevices b ased on the status o fthe drive.The co ntacts of the co ntrol card relay are rated for 50 VA C at 1 A m p. H ow ever,in U L ap plications,the rating is lim ited to 30 VD C at 1 Am p. The logic circuitry o n the controlcard allow forthe addition of o p tio n m o d u les fo r syn ch ro n izin g co n tro l, se rial co m m un ica tions, ad d itiona l relays, the ca sca d e p um p co ntroller,or cu stom operating so ftw are.
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Logic To Power Interface T he lo gic to p ow er interface iso lates the hig h vo ltage co m ponents ofthe pow er section from the low voltag e signals of the logic section. The interface section consists o f three separate circuit cards: the interface ca rd, power card, and card. gate driver The po w er card has been designed to acco m m od ate the controlcircuitry forthe next generation ofV LT drives. Forthis reason, an interface card, located betw een the co ntrolan d pow ercards in the currentseries ofdrives,provides translation betw een the tw o sign alschem es.M ostofthe com m unication betw ee n the c ontrollogic an d the rest of the d rive passes throu gh the po w er card.C om m unication w ith the pow ercard includ es m onitoring the D C bus vo ltag e, line voltag e, output current, along w ith control of inrush curren t an d the gate drive firing signals. M uch ofthe faultprocessing foroutputshortcircuitan d ground fau lt co nd itions is d one o n the p ow er ca rd . A cu stom application sp ecific integrated circuit(A S IC )continually m onitors output cu rren t co nd itions w ith respect to peak am plitude, rate of rise (di/dt) and leakage current (ground fault). A t the pointthatany o fthese conditions are considered critical,the gate drive signals are im m ed iately shut-offand an alarm signal is sentto the controllogic fordisp laying the faultinform ation. The po w ercard contains a sw itch m od e pow ersupp ly (S M P S ) w hich p rovides the u nit w ith 2 4 V D C , + 18 V D C , – 18 V D C an d 5 VD C operating voltag e. The logic an d interface circu itry is po w ered b y the S M P S . The S M P S is supp lied b y the D C bus vo ltag e. V LT 50 00 series d rives can be p urchased w ith the o ption of pow ering the S M P S w ith an external24 V D C pow er su pply. This enables operation o f the logic circuitry w itho ut the pow er section being energized . C ircuitry for controlling the cooling fan's auto transform er is also provided on the pow er card. In units w ith dynam ic b rake o ptions,the logic and firing circuitry for the brake operation is contained on the pow er card. A lso located on the pow er card is a relay for m onitoring the status of the d rive. The relay is Form C , m eaning it has one no rm ally op en co ntactand o ne n orm ally closed co ntacton a single throw .The co ntacts o fthe relay are rated fora m axim um load o f240 VA C at2 A m ps. The gate drive signals from the co ntrol card to the output transistors (IG B Ts)are isolated and buffered on the gate driver card.In units that have the d ynam ic b rake option,the d river circuits forthe brake transistors are also located on this c ard.
Power Section
The inverter section is made up of six IGBTs, commonly referred The high voltage power section consists of AC input terminals, to as switches. One switch is necessary for each half phase AC and DC bus bars, fusing, harnessing, AC output, and of the three-phase power, for a total of six. The six IGBTs are optional components. The power section (see Figure 2-3) also contained in a single module. Due to higher current handling contains circuitry for the soft charge and SCR/Diode modules requirements, the VLT 5202 - 5302 models contain two of in the rectifier; the DC bus filter circuitry containing the DC these six-pack style modules. In these units, each switch coils, often referred to as the intermediate or DC bus circuit; (half phase) is made up of two IGBTs in parallel. and the output IGBT modules which make up the inverter A Hall effect type current sensor is located on each phase of section. the output to measure motor current. This type of device is In conjunction with the SCR/Diode modules, the soft charge used instead of more common current transformer (CT) circuit limits the inrush current when power is first applied and devices in order to reduce the amount of frequency and phase the DC bus capacitors are charging. This is accomplished by distortion that CTs introduce into the signal. With Hall sensors, the SCRs in the modules being held off while charging current the average, peak, and ground leakage currents can be passes through the soft charge resistors, thereby limiting the monitored. current. The DC bus circuitry smoothes the pulsating DC voltage created by the co nversion from the AC supply. The DC coil is a single unit with two coils wound on a common core. One coil resides in the positive side of the DC bus and the other in the negative. The coil aids in the reduction of line harmonics. The DC bus capacitors are arranged into a capacitor bank along with bleeder and balancing circuitry. Due to the requirement for higher po wer capacity, the VLT 5202 - 5302 drives have two capacitor banks connected in parallel.
RECTIFIER (SCR/DIODES)
INTERMEDIATE CIRCUIT
INVERTER SECTION (IGBTs)
MOTOR COILS
L1
U
L2
V
L3
W
SOFT CHARGE CIRCUITRY
VLT is a registered Danfoss trademark
2-3
SEQUENCE OF OPERATION Rectifier Section W hen inputpow eris first applied to the drive,iten ters through the inp ut term inals (L1,L2,L3 )an d on to the disconne ct or/ an d R FI option, dep en ding on the unit's configuration (see Figure 2 -4).Ifequipped w ith o ptionalfuses,these fuses (FU 1, FU 2,FU 3)lim itdam ag e caused by a sho rtcircuitin the pow er section . Th e S C R s, in the co m bined S C R /D iod e m od ules, are n otgated so currentcan travelto the rectifier on the soft ch arge card.A dditionalfuses located on the softch arge card provide protection in the eventofa shortin the softch arge or fan circuits.Three phase pow er is also branch ed offand sen t to the p ow er card.Itprovides the p ow er card w ith a referen ce ofthe m ain supply voltag e and provides a supply voltag e for the co oling fans. D uring the charging process,the top diodes ofthe softcharge rectifierconductand rectify d uring the positive halfcycle.The diodes in the m ain rectifier conduct during the neg ative half cycle.The D C voltag e is applied to the b us capacitors through the softch arge resistor.The purpo se o fcharging the D C bus through this resistor is to lim it the high inrush current that w ou ld otherw ise b e p resen t. P ositive tem perature coefficient(P TC )resistors located on the so ft charge card are in series w ith the soft charge resistor. Freq uent cycling ofthe inp ut pow er or the D C bus c harging over an extended tim e can cau se the P TC resistors to heat up due to the cu rrent flow . R esistance of the P TC device increa ses w ith tem p erature, eve ntually ad d ing en ough resistance to the circuit to prevent significant current flow . This protects the so ftch arge resistorfrom dam ag e along w ith any other com po nents thatcou ld be dam aged by co ntinuo us attem pts to charge the D C bus. W hen the D C bu s reaches ap proxim ately 40 0 VD C , the low voltage pow er supplies are activated .A fter a short delay,an inrush en ab le signalis sentfrom the controlcard to the p ow er card S C R gating circu it. The S C R s are autom atically gated w hen forw ard b iased , acting, as a resu lt, sim ilar to an uncontrolled rectifier.
2-4
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W hen the D C bus capacitors are fully ch arged , the voltag e on the D C bus w illbe equalto the peak vo ltag e o fthe inp ut A C line. Theoretically, this can be calculated by m ultiplying the A C line value by 1.414 (VA C x 1.41 4).H ow ever,since A C ripple vo ltag e is p resen t on the D C bus, the actualD C value w illbe c loser to V A C x 1.38 un der un load ed co nd itions and m ay d rop to V A C x 1.32 w hile run ning un der load .Fo ra d rive co nnected to a nom inal460 V line, w hile sitting idle,the D C bus vo ltag e w illbe ap proxim ately 63 5 V D C . A s long as pow er is applied to the d rive,this vo ltage is p resent in the interm ediate circuit and the inverter circuit.Itis also fed to the S w itch M od e P ow erS up ply (S M P S )on the p ow ercard an d is used forgenerating allother low voltag e supplies.
Figure 2 -4. R ectifier C ircuit
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2-5
Intermediate Section Fo llo w ing the rectifier se ctio n, vo ltag e p asses to the interm ediate section.(see Figure 2-5).This rectified vo ltage is sm oothe d by an LC filter circu it co nsisting of the D C bus ind uctor and the D C bus ca pacitor bank. Th e D C bus ind uctor provides series im ped ance to changing current.This aids the filtering process w hile reducing harm onic distortion to the inputA C cu rren tw aveform norm ally inheren t in rectifiercircuits. The D C capacitor bank assem bly co nsists of six capacitors arranged in series/parallelconfiguration. H igher pow er units have tw o capacitorbanks assem blies. A lso co ntained w ithin the assem bly is the b leeder/balance circuitry. This circuitry m aintains eq ua l voltag e drops across each capacitor and provides a cu rren t path for discha rging the capacitors o nce po w er has b een rem oved from the d rive. A lso located in the interm ed iate section is the high freq uency (H F) filter card. It contains a high frequency filter circu it to red uce naturally occurring cu rren ts in the H F ran ge to preven t interference w ith other sensitive equipm en t in the area. The circuit, as w ith other R FI filter circuitry, can be sensitive to unbalanced phase-to-grou nd voltag es in the three-phase A C inputline.This can occasionally resultin nuisance o vervoltage alarm s. For this reaso n, the H F filter card co ntains a set of relay contacts in the ground connection ofthe filtercapacitors. The relay is tied into the R FI/H F sw itch on the interface card, w hich can be m an ually sw itched off. This d isco nn ects the ground reference s to allfilters should unbalance d phase-toground voltag es create n uisanc e o vervoltag e cond itions.
2-6
V LT is a registered D anfoss trad em ark
Figure 2-5.Interm ed iate S ec tion
V LT is a reg istered D anfoss trad em ark
2-7
Inverter Section In the invertersection (see Figure 2-6),gate signals are delivered from the co ntrolcard,through the pow er card an d gate d rive card to the gates of the IG B Ts. The series co nn ection of each set of IG B Ts is d elivered to the o utput, first passing through the curren tsensors. O nce a run com m and and speed reference are present,the IG B Ts beg in sw itching to create the output w aveform , as sho w n in Figure 2 -7.Lo oking at the phase-to-phase voltag e w aveform w ith an o scilloscope, itcan b e seen that the P ulse W idth M odulation (P W M )principalcreates a series ofpulses w hich vary in w idth. B asically, the pulses are narrow er as zero crossing is n ea red an d w ider the farther from zero crossing.The w idth is controlled by the pulse duration ofap plied D C voltag e. Tho ug h the voltag e w aveform is a co nsistant am plitude, the inductance w ithin the m otorw indings w illserve to averag e the voltag e d elivered and so,as the pulse w idth of the w aveform varies, the averag e voltag e seen by the m otor varies as w ell. This then equates to the resultan t cu rrent w aveform w hich takes on the sine w ave shap e that w e expect to see in an A C system . Th e freq uency of the w aveform is then determ ined by the rate a t w hich the pulses occur. B y em ploying a sophisticated co ntrolschem e,the drive is cap ab le ofdelivering a current w aveform that nearly replicates a true A C sine w ave. Th is w aveform , as generated by the D anfoss V V C plus P W M principle at the co ntrolcard, provides o ptim alperform an ce and m inim allosses in the m otor. H all effec t curren t senso rs m onitor the o utput cu rrent and deliverproportionalsignals to the p ow er ca rd w here they are buffered an d delivered to the co ntrol card. These cu rren t signals are used by the controlcard logic to d eterm ine p roper w aveform com pensation s b ased on load cond ition s. Th ey furtherserve to detectovercu rrentconditions,including ground fau lts and phase-to-phase sho rts o n the output.
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V LT is a registered D anfoss trad em ark
D uring no rm al operation, the pow er card an d co ntrolcard are m onitoring various functions w ithin the drive.The current sen sors provide current feedback inform ation. The D C bus voltag e and A C line voltag e are m onitored as w ell as the voltag e delivered to the m otor.A therm alsensorm oun ted on the he atsink provides tem perature feedback.
Figu re 2 -6. O utp ut V oltag e an d C urrent W aveform s
Figure 2 -7. Inverter S ection
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Brake Option Fo r drives equipped w ith the dynam ic b rake o ption, a b rake IG B T along w ith term inals 81(R -) an d 82(R + ) is included for co nnecting an externalbrake resistor. The function ofthe brake IG B T (see Figure 2-8)is to lim itthe voltag e in the interm ed iate circu it, w hen eve r the m axim um voltage lim itis exceeded.Itdoes this by sw itching the externally m ou nted resistor across the D C bu s to rem ove excess D C voltag e p resent on the bus capacitors.Excess D C bus vo ltag e is generally a resultofan overhauling load causing regenerative energy to be returned to the D C bus.This occurs,forexam ple, w he n the load drives the m otor causing the vo ltag e to return to the D C bus circu it.
P lac ing the b rake resistor externally has the advantag es of selecting the resistor based on application n eed,dissipating the energy outside o f the controlpanel, and protec ting the drive from overheating ifthe b rake resistor is overloaded. The B rake IG B T gate signal origina tes on the control card an d is d elivered to the brake IG B T via the pow er card and gate drive card. A dditionally, the pow er and control ca rds m onitor the brake IG B T and brake resistor co nn ection for shortcircuits and overloads.
Figure 2-8. B rake O p tion
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Cooling Fans A lldrives in this size range are equipped w ith cooling fans to provide airflow along the heatsink. U nits in N E M A 1 (IP 20) an d N E M A 12 (IP 54) en closures h ave, in addition, a fan m ounted in the en closure doorto provide ad ditionalairflow to the rest ofthe unit. A llfan s are p ow ered from an au to tran sform er that provides 230 V A C . O n/off and high/low speed co ntrolof the fans is provided to reduce o verallacousticalnoise an d extend the life ofthe fans. R eg ardless ofthe heatsink tem perature, the fan s are started sh ortly after m ain input pow er is a pplied to the drive. If the heatsink tem perature is b elow 86°F (30°C ),the fans w illturn offafter a shortinterval.A ta heatsink tem perature ofgreater than 1 13°F (45°C ), the fans are sw itched on at low speed. This eq uates to ap proxim ately 20 0 VA C ap plied to the fans. A t a heatsink tem perature o f m ore tha n 1 40°F (60°C ), full voltage is applied to the fan s to obtain fullsp ee d. W hen the heatsink tem perature returns to less tha n 131°F (55°C ), the fans return to low speed. B elow 86°F (30°C )the fans sw itch off. S ince the internalam bien ttem perature is m aintained by one or m ore 2 30 VA C fans, the transition betw een low and high sp eeds also occurs ifthe internalam bien trises,reg ardless of hea tsink tem p erature. The internal am b ien t tem p erature sensoris located on the pow ercard.Ifthe internaltem perature rises to greaterthan 149°F (65°C ),the fans w illsw itch to high sp ee d,regardless o fthe heatsink tem perature. Ifthe internal am bienttem perature returns to 122°F (50°C )and the heatsink tem perature rem ains b elow 140°F (60°C ),the fan s w illreturn to low speed . The fan s sw itch to high sp ee d sho uld a h ea tsink over tem p erature trip o ccur. In ad d itio n, reg ard less o f any tem perature, w he n the load cu rrent on the drive reaches 60% ofits continu ous rating the fan s are sw itch ed on at low sp eed an d the n follow the tem peratures a s listed ab ove.
Load Sharing U nits w ith the built-in load sharing option contain term inals 8 9 (+)D C an d 88 (-)D C .W ithin the d rive,these term inals co nnect to the D C b us in front of the D C link rea ctor an d b us capacitors. The use ofthe load sharing term inals can take o n tw o different configurations. In o ne m etho d, the term inals are u sed to tie the D C bus circuits o fm ultiple drives together.This allow s forthe possibility ofone d rive that is in a regenerative m ode to share its excess bus voltag e w ith an other drive that is in the m otoring m ode. W hen ap plied co rrectly,this can red uce the ne ed forexterna l dynam ic b rake resistors w hile also saving en ergy. In theo ry, the nu m ber of drives that can be c onn ected in this w ay is infinite,how ever,the drives m ustbe ofthe sam e voltage rating.
In ad dition, dep en ding on the size an d num ber of drives, it m ay b e n ecessary to installD C reactors an d D C fuse s in the D C link connection s and A C reactors on the m ains.A ttem pting such a configuration req uires sp ecific considerations and should notbe attem pted w ithoutfirstco nsulting D an foss A pplication Engineering. In the seco nd m ethod,the drive is p ow ered exclusively from a D C source. This is a bit m ore com plicated . First, a D C source is req uired . S econd , a m eans to soft charge the D C bus atpow er up is req uired .Last,a 2 30 VA C source is req uired to pow er the fan s w ithin the d rive.A gain such a c onfiguration should not be attem pted w ith out first co nsulting D an foss A pplication E ngineering.
Specific Card Connections C on nec tor FK 10 2 on the po w er card p rovide s for the co nn ection ofan externaltem perature sw itch .S uch an inp ut co uld be used to m onitorthe tem perature o fan externalbrake resistor.Tw o inputconfigurations are p ossible.A norm ally closed sw itch m ay be connected b etw een term inals 104 and 10 6 or a norm ally open sw itch b etw een term inals 10 4 and 10 5.S hould the inputch an ge states,the d rive w ould trip on an A larm 29, O vertem perature.Th e inp ut S C R s w ou ld also be d isab led to prevent further en ergy from being supplied to the D C bus. If no such input is u sed, or the norm ally o pen co nfiguration is selected ,a jum per m ust be installed betw een term ina ls 1 04 and 106. FK 103 provides for the co nn ection of 23 0 V A C to allow pow ering the A C co oling fans from an externalsource.This is req uired w hen the d rive is used in a load sharing ap plication w here no A C pow er is provided to the m ain inp ut term inals. To m ake use ofthis provision ,the jum pers w ould be rem oved from term ina ls 10 0 and 102,101 and 103.The au xiliary 23 0 V A C po w er supp ly w ould b e connected to term inals 100 and 101. There a re tw o FK 100 term inals, one on the interface card and on e on the p ow er card. The pow er card FK 100 provides a ccess to au xiliary relay 1 . This is a form C set ofco ntacts,m eaning one no rm ally open and one no rm ally closed co ntact on a sing le throw . Th e contacts are rated for a m axim um of24 0 V A C ,2 A m ps and a m inim um of24V D C ,10m A or 24 V A C ,100m A .The relay can be p rogram m ed via p aram eter 323 to ind icate d rive status. The interface card F K 100 is provided to accep t24 V D C from an externalsource.This inputprovides controlpow er to keep the controllogic and an y installed options p ow ered up an d com m unicating even w ith the m ain sup ply pow er rem oved from the drive.This is p articularly usefulform aintaining a bus co m m un ication s netw ork w hile so m e d rives are n ot being po w ered b y the m ains. Term inalpositions on the pow ercard labeled M K 40 0,M K 10 3, and FK 101 are reserved for future use. V LT is a reg istered D anfoss trad em ark
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SECTION 3 TROUBLESHOOTING TROUBLESHOOTING TIPS
Exterior Fault Troubleshooting
Before attempting to repair a drive, here are some tips to follow There may be slight differ ences of servicing a drive that has to make the job easier and possibly prevent unnecessary been operational for some extended period of time compared damage to functional components. to a new installation. With good troubleshooting techniques, however, it is not safe to make many assumptions. To assume 1. Note all warnings concerning voltages present in a motor is wired properly because the drive has been in service the drive. Always verify the prese nce of AC input for some time may overlook loose connections, improper voltage and DC bus voltage before working on programming, or added equipment, for example. It is best to the unit. Some points in the drive are referenced develop a detailed approach, beginning with a physical to the negative DC bus and are a t bus potential inspection of the system. See Table 3-1, Visual Inspection, for even though it may appear on diagrams to be a items to examine. neutral reference.
Fault Symptom Troubleshooting
2. Never apply power to a unit that is suspected of being faulty. Many faulty components within the drive can cause damage to other components when power is applied. Always perform the procedure for testing the unit after repair as described in Section 5, Test Procedures. 3. Never attempt to defeat any fault protection circuitry within the drive. That will re sult in unnecessary component damage and may cause personal injury. 4. Always use factory approved replacement parts. The drive has been designed to operate within certain specifications. Incorrect parts may effect tolerances and result in further damage to the unit. 5. Read the instruction and service manuals. A thorough understanding of the unit is the best approach. If ever in doubt, consult the factory or authorized repair center for assistance.
This troubleshooting section is divided into sections based on the symptom being experienced. To start Table 3-1 provides a visual inspection check list. Many times the root cause of the problem may be due to the way the drive has been installed or wired. The check list provides guidance through a variety of items to inspect during any drive service process. Next, symptoms are approached as the technician most commonly discovers them: reading an unrecognized drive display, problems with motor operation, or a warning or alarm displayed by the drive. Remember, the drive processor monitors inputs and outputs as well as internal drive functions, so an alarm or warning does not necessary indicate a problem within the drive itself. Each incident has further descriptions on how to troubleshoot that particular symptom. When necessary, further referrals are made to other parts of the m anual for additional procedures. Section 4, Drive and Motor Applications, presents detailed discussions on areas of drive and system troubleshooting that an experienced repair technician should understand for effective analysis. Finally, a list of tests called After Repair Tests is provided. These tests should always be performed when first starting a drive, when approaching a drive that is suspected of being faulty, or anytime following a repair to the drive. 3.0 Fault Symptoms 3.1 Display 3.1.1 No Display 3.1.2 Intermittent Display 3.1.3 Display Line 2 Flashing 3.1.4 WRONG Displayed 3.2 Motor 3.2.1 Motor Will Not Run 3.2.2 Incorrect Motor Operation 3.3 Warnings and Alarms 3.4 After Repair Tests
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3-1
Visual Inspection The table below lists a variety of conditions that should be inspected for visually as part of any initial troubleshooting procedure.
Inspect For Drive display Input power wiring Output to m otor wiring Ground ing
Control wiring
Programm ing Motor
Cable routing
Au xilia ry equipment
Drive cooling Drive interior
EMC considerations Vibration
Environmental conditions
Proper clearance
3-2
Description Warnings, alarms, drive status, fault history and many other important items are available through the display on the local control panel of drive. Check for loose connections. Check for proper fusing. Check for blown fuses. Check for loose connections. Check for switching components in output circuit. Check for faulty contacts in switch gear. The drive requires a dedicated ground wire from its chassis to the building ground. It is also suggested that the motor be grounded to the drive chassis as well. The use of conduit or mounting of the drive to a metal surface is not considered a suitable ground. Check for good ground connections that are tight and free of oxidation. Check for broken or damage d wires and connections. Check the voltage source of the signals. Though not always necessary depending on the installation conditions, the use of shielded cable or a twisted pair is recommended. Ensure the shield is terminated correctly. Refer to the section on grounding shielded cables in Section 1. Check that drive parameter settings are correct according to motor, application, and I/O configuration. Check nameplate ratings of motor. Ensure that motor ratings coincide with drives. Check that drive's motor parameters (102 – 106) are set according to motor ratings. Avoid routing motor wiring, AC line wiring, and signal wiring in parallel. I f parallel routing is unavoidable, try to maintain a sepa ration of 6 - 8 inches between the cables or separate them with a grounded conductive partition. Avoid routing cables through free air. Look for auxiliary equipment, switches, disconnects, or input fuses/circuit breakers that may reside on input power side of drive or output side to motor. Examine operation and condition of these items as possible causes for operational faults. Check function and installation of pressure sensors or encoders (etc.) used for feedback to drive. Check operational status of all cooling fans. Check door filters on NEM A 12 (IP54) units. Check for blockage or constrained air passages. Drive interior must be free of dirt, metal chips, moisture, and corrosion. Check for burnt or damaged power components or carbon deposits that were the result of a catastrophic component failure. Check for cracks or breaks in the housings of power semiconductors, or pieces of broken component housings loose inside the unit. Check for proper installation with regard to electromagnetic capability. Refer to the drive instruction manual and Section 4 of this manual for further details. Though somewhat subjective look for an unusual amoun t of vibration that the drive may be subjected to. The drive should be mounted solidly or the use of shock mounts employed. Under specific conditions these units can be operated within a maximum ambient of 50°C (122°F). Humidity levels must be less than 95% noncondensing. Check for harmful airborne contaminates such as sulfur based compounds. These drives require a top and bottom clearance of nine (9) inches to ensure proper air flow for cooling. Drives with exposed heat sinks out the back of the drive must be mounted on a flat solid surface.
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3.0 FAULT SYMPTOMS
3.1.3 Display (Line 2) Flashing
This indicates that a local stop command has been given by pressing the stop key on the front of the LCP keypad. The 3.1 DISPLAY drive cannot accept any further run command until the local stop is cleared. This is accomplished by pressing the [LOCAL START] key. For the VLT 4000/6000/8000 the [HAND START] 3.1.1 No Display The LCP display provides two display indications. One by means or [AUTO START] keys provide the same result. of the backlit LCD alphanumeric display. The other is three LED indicators lights near the bottom of the LCP. If the green power on LED is illuminated but the backlit display is dark , this Drive may start immediately. If drive is being indicates that the LCP itself is defective and must be replaced. operated in local control, or remote control with a maintained run signal, drive will start immediately. ALARM WARNING ON Be certain, however, that the display is completely dark. Having a single character in the upper corner of the LCP or just a dot indicates that communications may have failed with the control card. This is typically seen when a se rial bus communication option has been installed in the drive and is either not connected properly or is malfunctioning. If neither indication is available, then the source of the problem may be elsewhere. Proceed to the No Display test in Section 5 to carry out further troubleshooting steps.
3.1.4 WRONG or WRONG LCP Displayed If the message WRONG or WRONG LCP appears, this is due to a faulty LCP or the use of an incorrect LCP, such as an LCP from a VLT 6000 series drive being connected to a VLT 5000 series unit. Replace the LCP with a correct and functioning one.
3.1.2 Intermittent Display Cutting out or flashing of the entire display and power LED indicates that the power supply (SMPS) is shutting down as a result of being overloaded. This may be due to improper control wiring or a fault within the drive itself. The first step is to rule out a problem in the control wiring. To do this, disconnect all control wiring by unplugging the control terminal blocks from the control card. If the display stays lit, then the problem is in the control wiring (external to the drive). All control wiring should be checked for shorts or incorrect connections. If the display continues to cut out, follow the procedure for No Display as though the display were not lit at all.
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3-3
3.2 MOTOR This indicates that bit #1 (or #2, or #3) in the control word is logic “0”. This will only occur when the drive is being co ntrolled In the event that this symptom is detected, first verify that the via the serial communication bus. unit is properly power up (display is lit) and that there are no warning or alarm messages displayed. The most common A correct control word must be transmitted to the drive over cause of this is either incorrect control logic or an incorrectly the communication bus to correct this.
3.2.1 Motor will not run
programmed drive. Such occurrences will result in one or more of the following status messages being displayed. (VLT 5000 only) One of the digital input terminals 16, 17, 27, 29, 32, or 33 The “Stop/Reset” key (VLT 5000) has been pressed. Line 2 of (parameters 300, 301, 304, 305, 306, or 307) is programmed the display will also be flas hing when this occurs. for “Stop Inverse” and the corresponding terminal is low (logic “0”). Press the “Start” key. Note: For VLT 4000/6000/8000, the status message “Stop” will be displayed. Pressing the “Hand Start” or “Auto Start” will correct this.
Ensure that the above parameters are programmed correctly and that any digital input programmed for “Stop Inverse” is high (logic “1”).
This indicates that there is no start signal at terminal 18. Ensure that a start command is present at terminal 18. Refer to the Input Terminal Signal Test in Section 5.
Terminal 27 is low (no signal). Ensure that terminal 27 is logic “1”. Refer to the Input Terminal Signal Test in Section 5.
This indicates that a run command has been given to the drive but the reference (speed command) is zero or missing. Check control wiring to ensure that the proper reference signal is present at the drive input terminals and that the unit is properly programmed to accept the signal provided. Refer to the Input Terminal Signal Test in Section 5.
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Check that parameter 620 is not set to “Run With Inverter Disabled”. If the unit is equipped with external 24VDC option, check that the main power is applied to the drive . Note: In this case, the display will alternately flash Warning 8.
3.2.2 Incorrect Motor Operation Occasionally, a fault can occur where the motor will continue to run, but not in the correct manner. The symptoms and causes may vary considerably. Many of the possible problems are listed below by symptom along with recommended procedures for determining their causes.
Possible open winding in motor or open connection to motor. Perform Output Phase Imbalance Test in section 5 to ensure drive is providing correct output (see Motor Runs Rough above). Check motor for open windings. Check all motor wiring connections.
Possible incorrect reference (speed command). Ensure that the unit is programmed correctly according to the reference signal being used, and that all reference limits are set correctly as well. Perform Input Terminal Signal Test in section 5 to check for faulty reference signals.
Possible fault in brake circuit. Possible incorrect setting in brake parameters. Ramp down time too short. Note: May be accompanied by an alarm or warning message. Check all brake parameters and ramp down time (parameters 208, 400, 401, 402).
Possible incorrect parameter settings, faulty current feedback Perform Brake Check in section 5. circuit, loss of motor (output) phase. Check settings of all motor parameters, including all motor compensation settings (Slip Compensation, Load Compensation, etc.) For Closed Loop operation, check PID settings. Perform Input Terminal Signal Test in section 5 to check for faulty reference signals. Perform Output Phase Imbalance Test in section 5 to check f or loss of motor phase.
Possible over magnetization (incorrect motor settings), or an IGBT misfiring. Note: Motor may also stall when loaded or the drive may trip occasionally on Alarm 13. Check setting of all motor parameters. Perform Output Phase Imbalance Test in section 5. If output voltage is unbalanced, perform Gate Drive Signal Test in section 5.
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3.3 WARNING AND ALARM MESSAGES
WARNING 5 DC LINK VOLTAGE HIGH
WARNING 1 10 VOLT LOW
The intermediate circuit voltage (DC) is above the upper warning limit of 825VDC. The VLT is still operational.
The 10 VDC supply on terminal 50 of the control card is too low. Max capacity of terminal 50 is 17ma. The 10 VDC supply on terminal 50 is supplied from a 13 volt regulator that supplies option boards and the LCP. This condition may be caused by overloading terminal 50 or a short circuit in the Speed Potentiometer or related wiring.
Ramp Down time too short. (Parameter 208 or 210 for VLT 5000, 207 for VLT 4000/6000/ 8000.)
WARNING 6 DC LINK VOLTAGE LOW
If the 10 VDC is missing or low the most common link would The intermediate circuit voltage (DC) is below the lower warning be the control card as the faulty part (after the exte rnal wiring limit of 435VDC. The VLT is still operational. was removed and verified). Also see the Analog Input Test AC line voltage too low. (5.2.14.2) in Section 5. Check AC input line voltage.
WARNING/ALARM 2 LIVE ZERO ERROR
WARNING/ALARM 7 The current signal on terminal 60 is less than 50% of the value DC LINK OVERVOLT programmed in parameter 315, and parameters 317 and 318 The intermediate circuit voltage (DC) is above the overvoltage have been programmed for the time out function to be active. limit of 850VDC. It may be necessary to use dynamic braking. It is possible to choose between a warning only or a warning As an alternative in the VLT 5000, the Over Voltage Control and trip based on the selection of parameter 318. Manual (OVC) scheme can be activated in parameter 400. For the reset is possible once the fault is corrected. VLT 4000/6000/8000, the OVC function is always active and the setting of parameters 400 and 410 have no effect on this Faulty connection in control wiring, or faulty signal generating alarm. device (PLC, transducer, etc.). The voltage level detected will be displayed. Check connections of control wiring. Perform the Analog Input Test (5.2.14.2) in Section 5. Manual reset is possible.
WARNING/ALARM 3 NO MOTOR
Warns for 5 sec.; trips after 25 s ec.
(Not applicable for the VLT 4000/6000/8000 series.)
Ramp Down time (Parameter 208 or 210 for VLT 5000, 207 for VLT 4000/6000/8000) significantly too short.
The motor check function has been activated in parameter 122. During stop conditions the motor check is pe rformed.
See Overvoltage Trips in Section 4 for more details.
This warning will appear if the VLT fails to detect a motor.
WARNING/ALARM 8 DC LINK UNDERVOLT
Ensure connection between drive and motor.
The intermediate circuit voltage (DC) is below the Under voltage limit of 400 VDC. The unit will trip after a set period of time. On WARNING/ALARM 4 the VLT 5000 extended units with an external 24VDC supply, AC LINE PHASE LOSS this message will be displayed as long as input power is This alarm is derived from reading the AC ripple on the DC removed, however, the unit will not trip. Bus. It is intended to indicate a missing phase on the input AC The voltage level detected will be displayed. Manual reset is main voltage. possible. One phase of the input AC line is missing or ex tremely low, or AC line voltage too low for too long time. severe waveform distortion is present on the input line. Measuring the voltage and current, and verifying the wave form of both the input AC line and the output to the motor may be the first step to restoring proper operation of the drive. Refer to section 5, Dynamic Test Procedures, Input Voltage Test, Input Phase Imbalance Test, Output Phase Imbalance Test. See Mains Phase Loss Trips in Section 4 for more details. 3-6
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Check AC input line voltage. See Input Voltage Test in Section 5.
WARNING/ALARM 9 INVERTER TIME
WARNING/ALARM 12 TORQUE LIMIT/CURRENT LIMIT
The unit has been operating with the output current having The torque requirement of the motor is higher than the value been in the intermittent range (between 100% and 150%) for set in parameter 221 for the VLT 5000 or 215 for the VLT too long. A warning will be displayed when the ETR counter 4000/6000/8000 (in motor operation) or parameter 222 reaches 98%. When the counter reaches 100%, the drive will (regenerative operation). The warning will be present until the trip. The unit can be programmed to display the ETR counter. time programmed in parameter 409 for VLT 5000 or 412 for the VLT 4000/6000/8000 expires. Improperly sized drive and/or motor. Improperly programmed drive. Manual reset is possible. Compare the output current (as displayed b y the LCP) to the This normally indicates a mechanical overload on the motor, rated current of the drive and motor. or incorrect setting of para. 221, 222, (or 215 for the VLT 4000/6000/8000) or incorrectly set ramp up time (par a. 207 Ensure that the drive is programmed properly for the application. [206 - VLT 4000/6000/8000). See section 4, Drive and Motor Applications for more information. Check mechanical load on motor. Manual reset is only possible after the counter has gone below 90%.
WARNING /ALARM 10 MOTOR TIME
Ensure that para. 221, 222 [215] are set correctly. Check ramp up settings. See Drive and Motor Application in Section 4 for more information.
The unit’s ETR function has calculated an over temperature condition in the motor. This calculation is based on motor WARNING/ALARM 13 current, speed and the length of time these conditions exist, OVERCURRENT based on the settings of parameters 102 through 106. Based The peak output current limit of the unit has exceeded 165% on the selection in parameter 128 the unit will display a warning of the unit’s rating. After 1.5 seconds the unit will trip. or an alarm when the counter reaches 100%. This fault may be caused by shock loading or fast accel ramps Overloaded motor (mechanical) with high inertia loads. Incorrect settings of various group 1 parameters may also be the cause. Verify parameters 102 - 106 are set correctly. Check for mechanical overloading on motor shaft. Manual reset is possible after the ETR counter has counted to zero.
WARNING/ALARM 11 MOTOR THERMISTOR The motor thermistor function has been activated in parameter 128 and a thermistor is connected to either terminal 53 or 54 and programmed as such in parameter 308 or 311. Parameter 128 provides a choice of warning or alarm. Manual reset is possible. This warning or trip occurs when the input to terminal 53 or 54 is more than 3K Ohms impedance between that terminal and terminal 50 or when the voltage to the selected terminal is greater than 8 VDC. This could indicate an overheated motor. It is also possible that the connection has been broken.
This fault results in a Trip Locked condition. See Drive and Motor Application in Section 4 for more information.
ALARM 14 EARTH FAULT The unit has sensed output leakage current sufficient enough to determine that there is a ground fault in the motor or motor wiring. This fault results in a Trip Locked condition. Short circuit to ground in motor or motor wiring, or faulty current sensor. Measure resistance to ground of motor leads with megohmmeter to check for earth faults. Perform current sensor test (section 5). See Internal Drive Problems in Section 5.
Check for overheated motor (if Thermistor function is being used). Check for open connection by measuring voltage between corresponding terminal and terminal 55. A reading of greater than 8 VDC indicates an open connection.
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3-7
ALARM 15 SWITCH MODE FAULT
WARNING 20 EE ERROR CTRL CARD
The internal plus and/or minus 18 VDC power supply voltage is not within the specified range.
Fault in the EEPROM on the control card. A fault exists in the ability of the VLT to read and write information to the control card EEPROM.
This fault results in a Trip Locked condition. This is normally due to a faulty Control Card. Remove all I/O connectors from Control Card. If message remains, replace Control Card. See Switch Mode Power Supply Test (5.2.2) in Section 5.
ALARM 16 CURR.SHORT CIRCUIT This indicates that the instantaneous output current has exceeded the maximum level for that drive. This fault results in a Trip Locked condition. Refer to over current section in the application se ction.
Failed EEPROM on Control Card. The drive will operate normally and in most cases once the power is cycled the warning clears. If the problem halts operation replacement of control card m ay be needed.
ALARM 21 AUTO MOTOR ADAPT OK (Not applicable for the VLT 4000/6000/8000.) Auto-optimization OK. The automatic motor tuning function (AMA) has been completed successfully. It is necessary to manually reset to resume normal operation.
This is due to a phase to phase short circuit in motor or motor AMA Function has been completed successfully. wiring. No corrective action is needed. This alarm is displayed upon completion of AMA to indicate a requirement to reset the drive Check motor and cabling for shorts. after performing AMA.
WARNING/ALARM 17 STD BUS TIMEOUT
ALARM: 22 AUTO MOT ADAPT FAIL
Indicates the serial communication with the VLT has failed and the time out function has been activated. The delay time Auto-optimization not OK. The automatic motor tuning function programmed determines how long the warning will be present failed. The possible causes as shown in the display are listed below. The numbers in brackets will be logged as the value in before a trip, provided “stop and trip” has been selected. parameter 617. Manual reset is possible. Check settings of p. 102 - 106, and restart AMA. Loss of serial communication signal due to faulty wiring or communication equipment (PC, PLC, RS232/485 Adaptor, etc.) In case of non-standard motor, set p. 107 to “Enable RS” and restart AMA. Check connections on serial communication cable. Check [0] operation of communication equipment.
WARNING/ALARM 18 HPFB BUS TIMEOUT
AMA function was unable to be car ried out due to incorrect settings or incorrect results of AMA tests.
Indicates the communication between a field bus option (such Parameter 102, 103 or 105 has been set incorrectly. as DeviceNet) and the VLT has failed and the time out function Correct the setting and restart AMA. has been activated in parameter 804. The delay time programmed in parameter 803 determines how long the [1] warning will be present before a trip, provided “stop and trip” has been selected in parameter 804. Manual reset is possible. AMA function was unable to be car ried out due to incorrect settings or incorrect results of AMA tests. Faulty connection in communication wiring, or faulty control node (PLC) in communication network. Check connections The value entered in parameter 105 is too small for the VLT 5000. on serial communication cable. Enter correct the value. Note: the motor nameplate current, and the value entered in parameter 105, must be greater than 35% of the nominal rating of the VLT in order to carry out AM A. 3-8
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ALARM: 22 (continued) AUTO MOT ADAPT FAIL
WARNING/ALARM 23 BRAKE TEST FAILED
[2]
(Not applicable for the VLT 4000/6000/8000.)
AMA has detected asymmetrical impedance in the windings of the motor connected.
When a unit with braking is powered-up and a stop command is present, a brake test is performed automatically by the unit. If the result of this test indicates a fault condition in the brake circuit and parameter 404 is set to warning, a warning will be displayed. If Trip has been set in 404 an alarm will occur. The unit will be able to operate in this condition, however, the brake function will be inoperative.
The motor may be defective. Check motor and motor connections. [3] AMA function was unable to be c arried out due to incorrect settings or incorrect results of AMA tests.
Manual reset is possible.
The motor is too large for AMA to be carried out or the setting in parameter 102 is incorrect.
Possible causes for this are: No brake resistor connected, or a faulty connection to the brake resistor, defective brake resistor or a defective brake IGBT, faulty brake firing circuit (Power Card).
Ensure that the motor is sized correctly. Correct the setting and restart AMA. [4] AMA function was unable to be c arried out due to incorrect settings or incorrect results of AMA tests.
Check all brake resistor c onnection, check resistor, perform Brake IGBT test (Static Test Section).
WARNING 25 BRAKE RESISTOR FAULT
(Not applicable for the VLT 4000/6000/8000.) The motor is too small for AMA to be carried out or the setting in parameter 102 is incorrect. The brake resistor or the connection is short circuited. The unit will be able to operate in this condition, however, the brake Ensure that the motor is sized correctly. Correct the setting function will be inoperative. and restart AMA. Manual reset is possible. [5] Ground fault in brake resistor circuit, shorted resistor cable, AMA has failed after attempting to tune for a period in excess too low resistance in resistor. of what should be normal. Check all brake resistor connections for short circuits, check It is possible that the signal data b eing returned is noisy. resistor value. It is possible to make several attempts under these conditions and eventually get the unit to pass.
WARNING 26 BRK PWR WRN 100%
[6]
(Not applicable for the VLT 4000/6000/8000.)
The AMA function cannot be completed due to the application of a stop command by the user.
Failed Control Card or noise interference.
Brake resistor power 100%. The monitoring function has been activated in parameter 403. The power transmitted to the brake resistor is monitored over a 120 second period. The power is based on the values entered in parameters 401 and 402. If the calculated power being dissipated exceeds 100% a warning will occur based on the choice in parameter 403. If warning is selected the warning will disappear when the dissipated power drops below 80%.
Repeat AMA procedure, if fault reoccurs, replace Control Card.
Manual reset is possible.
[8]
Overhauling motor load, load inertia too high, ramp down time incorrectly set.
Repeat AMA procedure. [7] A fault has occurred internal to the VLT.
The parameter values programmed for the motor are outside the typical characteristics of the drive’s internal motor table. This is due to the use of a non-standard motor.
Check ramp down time (para. 208) settings. Check for overhauling motor load. If load inertia is too high, load must be reduced or drive and resistor must be resized .
Set p. 107 to “Enable RS” and restart AMA. If this fault reoccurs, AMA cannot be performed on this particular motor. [9] MOTOR ROTATES
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3-9
WARNING 27 BRAKE IGBT FAULT
ALARM 32 MISSING MOT. PHASE W
(Not applicable for the VLT 4000/6000/8000.)
The unit has detected an open circuit in the W phase.
The brake transistor is shorted. As a result of the shorted This fault may be manually reset. transistor substantial power may be transm itted to the brake Parameter 234 (VLT 5000 only) can disable the tripping or resistor. missing motor phase. Disconnect main input power to the VLT. Perform Brake IGBT This can be due to a faulty connection between drive and Test (5.2.11) in Section 5. motor, or a faulty motor.
ALARM 29 HEAT SINK OVER TEMP
Check motor wiring.
The heatsink temperature has exceeded 95°C. This fault results in a Trip Locked condition.
See Output Phase Imbalance Test (5.2.8) in Section 5.
sink or air flow path, defective therma l sensor.
This ind ica tes tha t the Quick Dis cha rge fea tur e is not functioning. Sequence of operation not correct.
ALARM 33 The possible causes are: defective cooling fan, blocked heat QUICK DISCHARGE NOT OK Check fan operation. Check for airflow blockage. Check for proper clearance above and below drive (see Instruction This fault results in a Trip locked condition. This feature is manual). Check fan filters (NEMA 12 units). Perform Heatsink available only with the VLT 5000 EB version. Temperature Sensor Test (5.1.6) in Section 5. Possible causes are: No 24V external power supply, brake ALARM 30 resistors not connected properly.
MISSING MOT. PHASE U The unit has detected an open circuit in the U phase. This fault may be manually reset. Parameter 234 (VLT 5000 only) can disable the tripping or missing motor phase.
Check connections of Brake resistor and External 24V Power Supply.
WARNING/ALARM 34 PROFIBUS COMMUNICATION FAULT The Profibus option is no longer communicating.
This can be due to a faulty connection between drive and A trip can be manually reset. motor, or a faulty motor. In a warning state this may indicate the cable has been Check motor wiring. disconnected or the master (PLC) has stopped. See Output Phase Imbalance Test (5.2.8) in Section 5.
ALARM 31 MISSING MOT. PHASE V The unit has detected an open circuit in the V phase. This fault may be manually reset. Parameter 234 (VLT 5000 only) can disable the tripping or missing motor phase.
In an alarm state it may indicate the option card is disturbed by noise or possibly defective. Check connections on serial communication cable. Check PLC.
WARNING 35 OUT OF FREQ. RANGE
This warning will only be displayed when operating in Process Closed Loop and the output frequency of the VLT is above or This can be due to a faulty connection between drive and below the limits programmed in parameters 201 and 202. motor, or a faulty motor. Parameter 455 (VLT 5000 only) can be programmed to disable this warning. Check motor wiring. This warning could indicate a loss of feedback or an undesired See Output Phase Imbalance Test (5.2.8) in Section 5. condition in the regulation process. Check connections in feedback circuit. Check process operation. Note: Some applications may be designed to operate normally in this mode. No action is necessary in this case. 3-10
VLT is a registered Danfoss trademark
WARNING/ALARM 36 MAINS FAILURE
WARNING 41 MOTOR TOO BIG
(Not applicable for the VLT 4000/6000/8000.)
AMA function has detected an error in calculating motor data.
The mains failure function has been activated in parameter The motor is too large for the VLT or the setting of parameter 407. A choice of actions is available including whether or not 102 is incorrect. to trip . A trip can be manually reset. Check the motor and setting and choose “Continue” or “Stop”. This is due to a loss of AC mains voltage. If stop is selected AMA will have to b e started over. Check AC mains voltage.
ALARM 37 INVERTER FAULT Indicates an IGBT is defective. This fault results in a Trip Locked condition. NOTE: Do not reset and reattempt to start the drive without taking corrective action. Further damage may re sult.
WARNING 42 MOTOR TOO SMALL AMA function has detected an error in calculating motor data. The motor is too small for the VLT or the setting of parameter 102 is incorrect. Check the motor and setting and choose “Continue” or “Stop”. If stop is selected AMA will have to b e started over.
Faulty IGBT.
ALARM 43 BRAKE FAULT
Measure gate to emitter resistance on all IGBTs.
(Not applicable for the VLT 4000/6000/8000.)
WARNING 39 CHECK Parameter 104, 106
A test of the brake function has failed.
The possible causes as shown in the display are listed below. The numbers in brackets will be logged as the value in parameter The settings in parameter 102, 104 or 106 are possibly set 617. incorrectly. These failures result in a Trip Locked condition. AMA function has detected an error in calculating motor data.
Check the setting and choose “Continue” or “Stop”. If stop is selected AMA will have to be started over.
WARNING: 40 CHECK Parameter 103, 105 AMA function has detected an error in calculating motor data.
Make corrections as needed. [0] During power up the brake test failed to find a resistor connected, or the resistance between terminals 81, 82 is too high.
The settings in parameter 102, 103 or 105 are possibly set Verify that the brake resistor is properly connected to terminals incorrectly. 81, 82. Check the setting and choose “Continue” or “Stop”. If stop is [1] selected AMA will have to be started over.
WARNING 41 MOTOR TOO BIG AMA function has detected an error in calculating motor data. The motor is too large for the VLT or the setting of parameter 102 is incorrect.
During the brake test the VLT 5000 has found a short circuit at the brake terminals, or the resistance between terminals 81, 82 is too low. Verify no shorts exist at the terminals and the brake resistor is the proper value for the VLT 5000.
[2] Check the motor and setting and choose “Continue” or “Stop”. The brake transistor is shorted If stop is selected AMA will have to be started over. As a result of the shorted transistor substantial power may be transmitted to the brake resistor. Disconnect input power to the unit. Perform Brake IGBT Test (5.2.11) in Section 5). It may be possible to run the drive with the brake resistor disconnected, however the braking function will be inoperative. VLT is a registered Danfoss trademark
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WARNING/ALARM 44 ENCODER FAULT
WARNING: 65 FEEDBACK
This message active for VLT 5000 units programmed for Speed The re su lting fe ed ba ck va lue is lowe r than the va lue Closed Loop operation only. The measured feedback differs programmed in parameter 227 Warning: Low feedback. from the reference by more than 3 x slip RPM. This is a customer programmable indicator of operating The encoder signal is interrupted from terminal 32 or 33. conditions. Check the connections of encoder device.
No corrective action needed.
ALARM 60 EXTERNAL FAULT
WARNING: 66 FEEDBACK>FDB HIGH
Terminal 27 must have a logic “1” for the unit to operate.
This is a customer programmable indicator of operating conditions.
Parameter 304 has been programmed for Safety Interlock and The resulti ng fee dback val ue is hig her tha n the value programmed in parameter 228 Warning: High feedback. a logic “0” is present at ter minal 27.
This fault can be manually reset.
The following Warning/Alarms are only applicable to the VLT 4000/6000/8000 series drives.
WARNING: 62 FOUT>FHIGH
No corrective action needed.
WARNING: 67 REF.
Output frequency high.
This is a customer programmable indicator of operating conditions.
The output frequency is higher than the value programmed in parameter 224 Warning: High frequency.
No corrective action needed.
This is a customer programmable indicator of operating conditions. No corrective action needed.
WARNING: 68 REF.>REF HIGH The remote reference is higher than the value programmed in parameter 226 Warning: High reference.
WARNING/ALARM: 63 I MOTOR
This is a customer programmable indicator of operating conditions.
Output current low.
No corrective action needed.
The output current is lower than the value programmed in parameter 221 Warning: Low current
WARNING: 69 TEMP.AUTO DERATE
Select the required function in parameter 409 function in case of no load.
Temperature auto derate. The heatsink temperature has exceeded the max value and the auto derating function (par. 411) is active. Warning: Temp. auto derate.
WARNING: 64 I MOTOR>I HIGH The output current is higher than the value programmed in parameter 222 Warning: High current.
See Warning/Alarm 29
WARNING: 99 UNKNOWN ALARM
This is a customer programmable indicator of operating An unknown fault has occurred which the software is not able to handle. conditions. No corrective action needed.
This may be due to noise interference, or a faulty Control Card. Cycle power and or reinitialize the VLT to clear the fault. Possible replacement of control card is needed.
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VLT is a registered Danfoss trademark
3.4 AFTER REPAIR TESTS Following any repair to a drive or for testing a drive suspected of being faulty, the following procedure must be followed to ensure that all circuitry in the drive is functioning properly before putting the unit into operation. 1. Perform visual inspection procedures as described in Table 3-1. 2. Perform static test procedures 5.1.1 to 5.1.3 to ensure drive is safe to start. 3. Disconnect motor leads from output terminals (U, V, W) of drive. 4. Apply AC power to drive. 5. Give drive a run command and slowly increase reference (speed command) to approximately 40 Hz. 6. Using an analog volt meter or a DVM capable of measuring true RMS, measure phase-to-phase output voltage on all three p hases: U to V, U to W, V to W. All voltages must be balanced within 8 volts. If unbalanced voltage is measured, refer to Input Voltage Test (5.2.1.1) in Section 5. 7. Stop drive and remove input power. Allow 15 minutes for DC capacitors to fully discharge. 8. Reconnect motor leads to drive output terminals (U, V, W). 9. Reapply power and restart drive. Adjust motor speed to a nominal level. 10. Using a clamp-on style ammeter, measure output current on each output phase. All currents should be balanced. If unbalanced current is measured, refer to Current Sensor Test (5.2.12) in Section 5.
VLT is a registered Danfoss trademark
3-13
SECTION 4 DRIVE AND MOTOR APPLICATIONS
Torque Limit, Current Limit, and Unstable Motor Operation
Parameter 107 activates the automatic motor adaptation (AMA) function. When AMA is performed, the drive measures the electrical characteristics of the motor and sets various drive parameters based on the findings. Two key parameter values set by this function are stator resistance and stator reactance, parameters 108 and 109. If unstable motor operation is experienced and AMA has not been per formed, it should be done. AMA can only be performed on single motor applications within the programming range of the drive. Consult the instruction manual for more on this function.
Excessive loading of the drive may result in warning or tripping on torque limit, over current, or inverter time. This is not a concern if the drive is properly sized for the application and intermittent load conditions cause anticipated operation in torque limit or an occasional trip. However, nuisance or unexplained occurrences may be the result of improperly setting specific parameters. The following parameters are important in matching the drive to the motor for optimum operation. These setting need careful attention, particular ly for the Parameters 108 and 109, as stated, should be set by the selectable torque drives of the VLT 5000 series. For the VLT AMA function or left at the factory default values. Never adjust 4000/6000/8000 series, torque settings are constant. these parameters to random values even though it may seem to improve operation. Such adjustments can result in Parameters 100 and 101 set the mode in which the drive unpredictable operation under changing conditions. will operate.
Parameter 221, Torque Limit , sets the limit for drive torque. Parameters 102 through 107 match the drive to the motor The factory setting is 160% for VLT 5000 series and 110% for and adapt to the motor characteristics. VLT 4000/6000/8000 series and will vary with motor power setting. For example, a drive programmed to operate a smaller Parameters 221 and 409 set the torque control features rated motor will yield a higher torque limit value than the same of the drive for the application. drive programmed to operate a larger size motor. It is important that this value not be set too low for the requirements of the Parameter 100, Configuration, sets the drive for open or closed application. In some cases, it may be desirable to have a loop operation or torque mode operation. In a closed loop torque limit set at a lesser value. This offers protection for the configuration,a feedback signal controls the drive speed. The application in that the drive will limit the torque. It may, however, settings for the PID controller play a key role for stable operation require higher torque at initial start up. Under these in closed loop, as described in the operator's manual. In open circumstances, nuisance tripping m ay occur. loop, the drive calculates the torque requirement based on Parameter 409, Trip Delay Torque, works in conjunction with current measurements of the motor. torque limit in the VLT 5000 series. This parameter selects the Parameter 101, Torque Characterisitcs, for the VLT 5000 series, length of time the drive operates in torque limit prior to a trip. sets the drive for constant or variable torque operation. It is The factory default value is off. This means that the drive will imperative that the correct torque characteristic is selected, not trip on torque limit, but it does not mean it will never trip based on the application. If, for example, the load type is from an overload condition. Built into the drive is an internal constant torque, such as a conveyor, and variable torque is inverter thermal protection circuit. This circuit monitors the selected, the drive may have gr eat difficulty starting the load, output load on the inverter. If the load exceeds 100% of the if started at all. Consult the factory if uncertain about the torque continuous rating of the drive, a timer is activated. If the load characteristics of an application. remains excessive long enough, the drive will trip on inverter time. Adjustments cannot be made to alter this circuit. Parameters 102 through 106 configure the drive for the Improper parameter settings effecting load current can result connected motor. These are motor power, voltage, frequency, in premature trips of this type. The timer can be displayed. current, and rated motor speed. Accurate setting of these parameters is very important. Enter the motor data requred as listed on the motor nameplate. For effective and efficient load control, the drive relies on this information for calculating the output waveform in response to the changing demands of the application.
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Overvoltage Trips
Mains Phase Loss Trips
This trip occurs when the DC bus voltage reaches a level of approximately 840 VDC. Prior to the trip, the drive will display a high voltage warning. Most times an over voltage condition is due to fast deceleration ramps with respect to the inertia of the load. During deceleration of the load, inertia of the system acts to sustain the running speed. Once the motor frequency drops below the running speed, the load begins overhauling the motor. At this point the motor becomes a generator and starts returning energy to the drive. This is called regenerative energy. Regeneration occurs when the speed of the load is greater than the commanded speed. This return voltage is rectified by the diodes in the IGBT modules and raises the DC bus. If the amount of returned voltage is too high, the drive will trip.
The drive actually monitors phase loss by monitoring the amount of ripple voltage on the DC bus. Ripple voltage on the DC bus is a product of a phase loss. The main concern is that ripple voltage causes overheating in the DC bus c apacitors and the DC coil. Left unchecked, the lifetime of the capacitors and DC coil would be drastically reduced.
There are a few ways to overcome this situation. One method is to reduce the deceleration rate so it takes longer for the drive to decelerate. A general rule of thumb is that the drive can only decelerate the load slightly faste r than it would take for the load to naturally coast to a stop. A second met hod is to allow the overvoltage control circuit to take care of the deceleration ramp. When enabled in parameter 400, the overvoltage control circuit regulates deceleration at a rate that maintains the DC bus voltage at an acceptable level. One caution with overvoltage control is that it will not make corrections to unrealistic ramp rates. For example, if the deceleration ramp needs to be 100 seconds due to the inertia, and the ramp rate is set at 3 seconds, overvoltage control will initially engage and then disengage and allow the drive to trip. This is pu rp os el y do ne so th e unit s op er at io n is no t misinterpreted. A third method in controlling regenerated energy is with a dynamic brake. With this system the optional brake electronics are built into the VLT 5000 drive with an external resistor bank mounted outside of the drive. The drive monitors the level of the DC bus. Should the level become too high, the drive switches the resistor across the DC bus and dissipates the unwanted energy into the resistor bank. This will actually increase the rate of deceleration. Less often is the case that the overvoltage condition is cause d by the load while it is running at speed. In this case the dynamic brake option can be used or the overvoltage control circuit. It works with the load in this way. As stated earlier, regeneration occurs when the speed of the load is greater than the commanded speed. Should the load become regenerative while the drive is running at a steady state speed, the overvoltage circuit will increase the frequency to match the speed of the load. The same restriction on the amount of influence applies. The drive will add about 10% to the base speed before a trip occurs. Otherwise, the speed could continue to rise to potentially unsafe levels.
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VLT is a registered Danfoss trademark
When the input voltage becomes unbalanced or a phase disappears completely, the ripple voltage increases causing the drive to trip and issue an Alarm 4. In addition to missing phase voltage, increased bus ripple can be caused by a line disturbance or imbalance. Line disturbances may be caused by line notching, defective transformers or other loads that may be effecting the form factor of the AC waveform. Line imbalances which exceed 3% cause sufficient DC bus ripple to initiate a trip. Output disturbances can have the same effect of increased ripple voltage on the DC bus. A missing or lower than normal output voltage on one phase can cause increased ripple on the DC bus. Should a mains imbalance trip occur, it is necessary to check both the input and output voltage of the drive. Severe phase imbalance or phase loss can easily be detected with a volt meter. Line disturbances most likely need to be viewed on an oscilloscope. Conduct tests for input phase imbalance, input waveform, and output phase imbalance a s described in Section 5.
Control Logic Problems Problems with control logic can often be difficult to diagnose, since there is usually no associated fault indication. The typical complaint is simply that the drive does not respond to a given command. There are two basic commands that must be given to any drive in order to obtain an output. First, the drive must be told to run (start command). Second, the drive must be told how fast to run (reference or speed command). The drives are designed to accept a variety of signals. First determine what types of signals the drive is receiving. There are eight digital inputs (terminals 16, 17, 18, 19, 20, 27, 29, 32, 33), three analog inputs (53, 54, 60), and the serial communication bus (68, 69). The presence of a correct reading will indicate that the desired signal has been detected by the microprocessor of the drive. See Drive Inputs and Outputs in Section 1.
requirements of the particular installation. References are set in the 200s parameter group. Incorrectly set I/O configuration usually results in the drive not responding to the function as commanded. It must be remembered that for every control terminal input or output there are corresponding parameters settings. These determine how the drive responds to an input signal or the type of signal present at that output. Utilizing an I/O function must be thought of as a two step process. The desired I/O terminal must be wired properly, and the corresponding parameter must be set accordingly. Control terminals are programmed in the 300s parameter group.
Motor/Load Problems Problems with the motor, motor wiring or mechanical load on the motor can develop in a number of ways. The motor or motor wiring can develop a phase-to-phase or phase-toground short resulting in an alarm indication. Checks must be made to determine whether the problem is in the motor wiring or the motor itself.
Using the status information displayed by the drive is the best method of locating problems of this nature. By changing parameter 009 (VLT 5000) or parameter 007 (VLT 4000/6000/ 8000), line 2 of the display can be set to indicate the signals A motor with unbalanced, or non-symmetrical, imp edances coming in. The presence of a correct reading indicates that on all three phases can result in uneven or rough operation, or the desired signal is detected by the microprocessor of the unbalanced output currents. Measurements should be made drive. with a clamp-on style ammeter to determine whether the If there is not a correct indication, the next ste p is to determine current is balanced on the three output phases. See 5.2.8, whether the signal is present at the input terminals of the drive. Output Phase Imbalance Test procedure. This can be performed with a voltmeter or oscilloscope in An incorrect mechanical load will usually be indicated by a accordance with the 5.2.14, Input Terminal Signal Test. torque limit alarm or warning. Disconnecting the motor from If the signal is present at the terminal, the control card is the load, if possible, can determine if this is the case. defective and must be replaced. If the signal is not present, Quite often, the indications of motor problems are similar to the problem is external to the drive. The circuitry providing the those of a defect in the drive itself. To determine whether the signal along with its associated wiring must then be checked. problem is internal or external to the drive, disconnect the motor from the drive output terminals. Perform the output phase Programming Problems Difficulty with drive operation can be a result of improper imbalance test procedure (5.2.8) on all three phases with an programming of the drive parameters. Three areas where analog voltmeter. If the three voltage measurements are programming errors may affect drive and motor operation are balanced, the drive is functioning correctly. The problem motor settings, references and limits, and I/O configuration. therefore is external to the drive. See Drive Inputs and Outputs in Section 1. The drive must be setup correctly for the motor(s) connected to it. Parameters 102 – 106 must have data from the motor nameplate entered into the drive. This enables the drive processor to match the drive to power characteristics of the motor. The most common result of inaccurate motor data is the motor drawing higher than normal amounts of current to perform the task expected of it. In such cases, setting the correct values to these parameters and performing the automatic motor adaptation (AMA) function will usually solve the problem.
If the voltage measurements are not balanced, the drive is malfunctioning. This typically means that one or more output IGBT is not switching on and off correctly. This can be a result of a defective IGBT or gate signal from the gate driver card. Perform the IGBT gate signal test (5.2.9).
Any references or limits set incorrectly will result in less than acceptable drive performance. For instance, if maximum reference is set too low, the motor will b e unable to reach full speed. These parameters must be set according to the VLT is a registered Danfoss trademark
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INTERNAL DRIVE PROBLEMS The vast majority of problems related to failed drive power components can be identified by performing a visual inspection and the static tests as described in the test section. There are, however, a number of possible problems that must be diagnosed in a different manner. The following discusses many of the most common of these problems.
Overtemperature Faults In the event that an overtemperature indication is displayed, determine whether this condition actually exists within the drive or whether the thermal sensor is defective. Of course, this can easily be detected by feeling the outside of the unit, if the overtemperature condition is still present. If not, the temperature sensor must be checked. This can be done with the use of an ohmmeter in accordance with the thermal sensor test procedure.
Current Sensor Faults
When the sensor becomes defective, the output voltage level varies by more than the 15mv allowed. The defective current sensor in that phase indicates current flow when there is none. This results in the sum of the three output currents being a value other than zero, an indication of leakage current flowing. If the deviation from zero (current amplitude) approaches a specific level, the drive assumes an earth fault and issues an alarm. The simplest method of determining whether a current sensor is defective is to disconnect the motor from the drive, then observe the current in the display of the drive. With the motor disconnected, the current should, of course, be zero. A drive with a defective current sensor will indicate some current flow. Because the current sensors for the higher horsepower drives have less resolution, an indication of a fraction of an amp on a drive is tolerable. However, that value should be considerably less than one amp. Therefore, if the display shows more than one amp of current, there is a defective current sensor.
When a current sensor fails, it is indicated sometimes by an To determine which current sensor is defective, measure the overcurrent alarm that cannot be reset, even with the motor voltage offset at zero current of each curre nt sensor. See the leads disconnected. Most often, however, the drive will current sensor test procedure (5.2.12). experience frequent false earth fault trips. This is due to the DC offset failure mode of the sensors. To explain this it is necessary to investigate the internal makeup of a Hall effect type current sensor. Included inside the device is an op-amp to amplify the signal to usable levels in the receiving circuitry. Like any op-amp, the output at zero input level (zero current flow being measured) should be zero volts, exactly half way between the plus and minus power supply voltages. A tolerance of +/- 15mv is acceptable. In a three phase system that is operating correctly, the sum of the three output currents should always be zero.
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A disturbance to other nearby equipm ent is more common. Generally, other industrial control equipment has a high level of EMI immunity. However, non-industrial, commercial, and Following is an overview of general signal and power wiring consumer equipment is often susceptible to lower lev els of considerations when addressing the Electromagnetic EMI. Detrimental effects to these systems may include the Compatibility (EMC) concerns for typical commercial and following: industrial equipment. Only certain high-frequency phenomena (RF emissions, RF immunity) are discussed. Pressure/flow/temperature signal transmitter Low-frequency phenomena (harmonics, line voltage signal distortion or aberrant behavior imbalance, notching) are not covered. Special installations or compliance to the European CE EMC directives will Radio and TV interference require strict adherence to relevant standards and is not presented here. Telephone interf erence
Signal and Power Wiring Considerations for Drive Electromagnetic Compatibility
Effects of EMI
Computer network data loss
While Electromagnetic Interference (EMI) related disturbances to drive operation are uncommon, the following detrimental EMI effects may be see n:
Sources of EMI
Motor speed fluctuations Serial communication transmission errors Drive CPU exception faults Unexplained drive trips
Rectifier
Digital control system faults
Modern adjustable frequency drives (see Figure 4-1) utilize Insulated-Gate Bipolar Transistors (IGBTs) to provide an efficient and cost effective means to create the P ulse Width Modulated (PWM) output waveform necessary for accurate motor control. These devices rapidly switch the fixed DC bus voltage creating a variable frequency, variable voltage PWM waveform. This high rate of voltage change [d V/dt] is the primary source of the drive generated EMI.
DC Bus
Inverter
Filter reactor
AC Line
Motor
IGBT
Filter capacitor
Sine wave
PWM waveform
The high rate of voltage change caused by the IGBT switching creates high frequency EMI.
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4-5
EMI Propagation Drive generated EMI is both conducted to the AC line and radiated to nearby conductors. See Figures 4-2 and 4-3 for illustrations.
VFD Motor AC Line
Motor cable
VLT
Stray capacitance
Ground
Potential 1
St
Potential 2
Potenti
Stray capacitance between the motor conductors, equipment ground, and other nearby conductors results in induced high frequency currents.
High ground circuit impedance at high frequencies results in an instantaneous voltage at points reputed to be at “ground potential.” This voltage can appear throughout a system as a common mode signal that can interfere with control signals. Theo retic ally, thes e curre nts will retur n to the driv e’s DC bus via the ground circuit and a High Frequency (HF) byp ass network within the drive itself. However, imperfections in the drive grounding or the equipment ground system can cause some of the currents to travel out to the power network.
VFD AC Line
Motor Motor cable
VLT
Stray capacitance
Signal wiring
Unprotected or poorly routed signal conductors located close to or in parallel to motor and AC line conductors are susceptible to EMI .
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VLT is a registered Danfoss trademark
to BMS
Signal conductors are especially vulnerable when they are run parallel to the power conductors for any distance. EMI coupled into these conductors can affect either the drive or the interconnected control device. See Figure 4-4. While these currents will tend to travel back to the drive, imperfections in the system will cause some current to flow in undesirable paths thus exposing other locations to the EMI.
VFD Motor AC Line
Motor cable
VLT
Stray capacitance
AC Line
HF currents can be coupled into the AC line supplying the drive when the AC line conductors are located close to the motor cables.
Preventative Measures EMI related problems are more effectively alleviated during the design and installation phases rather then after the system is in service. Many of the steps listed here can be implemented at a relatively low cost when compared to the cost to later identify and fix the problem in the field.
Signal cable selection Single conductor 600 volt rated wires provide the least protection from EMI. Twisted-pair and shielded twist-pair cables are available which are specifically designed to minimize the effects of EMI. While unshielded twisted-pair cables are often adequate, shielded twisted-pair cables provide another degree of protection. The signa l cable’s shield should be terminated in a manner that is appropriate for the connected equipment. Avoid terminating the shield through a pigtail connection as this increases the HF impedance and spoils the effectiveness of the shield. Refer to Section 1, Grounding Shielded Cables.
Grounding The drive and motor should be solidly grounded to the equipment frame. A good HF connection is necessary to allow the HF currents to return back to the drive rather than to travel thorough the power network. The ground connection will be ineffective if it has high impedance to HF currents, therefore it should be as short and direct as A simple alternative is to twist the existing single conductors practical. Flat braided cable has lower HF impedance than to provide a balanced capacitive and inductive coupling round cable. Simply mounting the drive or motor onto a thus canceling out differential-mode interference. While not painted surface will not create an effective ground as effective as true twisted-pair cable, it can be connection. In addition, running a separate ground implemented in the field using the materials on hand. conductor directly betwe en the drive and the driven motor is recommended. Cable routing Avoid routin g motor wiring, AC line wiring, and signal wiring in parallel. If parallel routing is unavoidable, try to maintain a separation of 6 - 8 inches between the cables or separate them with a grounded conductive partition. Avoid routing cables through free air.
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4-7
Motor cable selection. The management of the motor conductors has the greatest influence on the EMI characteristics of the system. These conductors should receive the highest attention whenever EMI is a problem. Single conductor wires provide the least protection from EMI emissions. Often if these conductors are routed separately from the signal and AC line wiring then no further consideration is needed. If the conductors are routed close to other susceptible conductors, or if the system is suspected of causing EMI problems then alternate motor wiring methods should be considered. Installing shielded power cable is the most effective me ans to alleviate EMI problems. The cable’s shield forces the noise current to flow directly back to the drive before it gets back into the power network or takes other undesirable and unpredictable high frequency paths. Unlike most signal wiring, the shielding on the mo tor cable should be terminated at both ends. If shielded motor cable is not available, then 3 phase conductors plus ground in a conduit will provide some degree of protection. This technique will not be as effective as shielded cable due to the unavoidable contact of the conduit with various points within the equipment.
4-8
VLT is a registered Danfoss trademark
Serial communications cable selection There are various serial communication interfaces and protocols on the market. Each of these recommends one or more specific types of twisted-pair, shielded twisted-pair, or proprietary cables. Refer to the manufacturer’s documentation when selecting these cables. Similar recommendations apply to serial communication cables as to other signal cab les. Using twisted-pair cables and routing them away from power conductors is encouraged. While shielded cable provides additional EMI protection, the shield capacitance may reduce the maximum allowable cable length at high data rates.
Proper EMC Installation Shown in Figure 4-5 is a correct installation with EMC considerations in mind. Although most insta llations will not follow all the recommended practices the closer an installation resembles this example the better immunity the network will have against EMI. Should EMI problems arise in an installation, refer to this example. Attempt to replicate this installation recommendation as closely as possible to alleviate such problems.
SECTION 5 TEST PROCEDURES
INTRODUCTION
! DANGER Touching electrical parts of drive may be fatal even after equipment has been disconnected from AC power. Wait 15 minutes after power has been removed before touching any internal components to ensure that capacitors have fully discharged. This section contains detailed procedures fortesting VLT drives. P revious sections o f this m anualprovide sym ptom s, alarm s an d other co nd itions w hich req uire follow ing these test proce dures in order to further diag nose the drive.The results ofthese tests w illindicate the appropriate rep airactions.A gain, because the drive m onitors input an d output signals, m otor cond itions,A C and D C pow er and otherfunction s,the source offaultconditions m ay exist outside ofthe drive itself.Testing described here w illisolate to m any ofthese co nditions as w ell. S ection 6,Disassembly and Assembly Instructions ,describes d etailed p ro ce d ures fo r rem o ving a nd rep lac ing d rive com pon ents,as req uired . D rive testing is divided into 5.1 Static Tests ,5.2 Dynamic Tests , and 5.3 Initial Start Up or Aft er Repair Drive Tests .S tatic tests are perform ed w itho ut the need forpow er applied to the drive. M ost drive p rob lem s can b e d iagno sed sim ply by perform ing these tests. S tatic tests can be perform ed w ith little or no disassem bly ofeq uipm entreq uired .The purpose ofperform ing static tests is to check forshorted pow er com ponents.P erform these tests on a ny unit that is su sp ected ofcontaining faulty pow er com ponents p rior to ap plying pow er.
Signal Test Board The signaltest board can be used to test circu itry w ithin the drive an d is p rovided for ease o f access to test points. The testor plugs into co nnector M K 104 on the interface card. Its use is d escribed in the procedures w here called out. S ee S ection 7 , Signal Test Board ,for detailed pin descriptions.
S ignalTest B oard
Test Cable The test cable supplies D C bus voltag e to the pow er card from the soft charge card bypassing the m ain D C bus. Th e S C R shorting plug ensures that the S C R s do n ot fire. This provides pow erfortesting the p ow ercard w ithoutdrive circuitry being pow ered . Th e cable co nnects be tw een soft charge connector M K 3 and pow ercard con nector M K 105.
D ynam ic tests are p erform ed w ith p ow er ap plied to the drive. D yn am ic testing traces signal circuitry to iso late to faulty com ponents. R ep lace any d efective com ponent and retest the d rive w ith the new com pon ent before applying pow er to the drive as described in 5 .3 Initial Start U p or Aft er Repair Drive Tests .
TOOLS REQUIRED FOR TESTING
Test C ab le C on ne ctor and S C R S ho rting P lug
D igitalvolt/ohm m eter cap ab le ofreading realR M S A nalog voltm eter O scilloscope C lam p-on style am m eter S ignaltest board p/n 176F 84 3 Testcab le p/n 17 6F 84 39
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5-1
5.0 TEST PROCEDURES 5.1 STATIC TEST PROCEDURES A lltests should be m ad e w ith a m eter capab le oftesting diodes. U se a digitalvolt/ohm m eter (V O M )set on the diode scale or an analog ohm m eter seton R x100 scale.B efore m aking any ch ec ks d isconnec t all inp ut, m o to r an d b rak e resistor co nnections.
NOTE For best troubleshooting results, it is recommended that static test procedures described in this section be performed in the order presented.
D iod e D rop . A diod e d rop read ing w illvary depending on the m od el of oh m m eter. W hatever the o hm m eter displays as a Figure 5 -1. Interface PCA and Pow er Card PCA Co nnector typicalforw ard b ias diode is defined as a "diode d rop" in these is p rovid ed as a reference for find ing the proced ures.W ith a typicalD VM ,the voltage drop across m ost Identification ap propriate co nn ectors described in the test proced ures in com ponents w illbe aroun d .300 to .500.The opposite reading this section. is referred to as infinity and m ost D M Vs w illdisp lay the value O L foroverload . MK100
MK104 MK102
MK105
MK101
MK103 Current scaling card
MK105(A) +DC
Interface Card
MK105(B) -DC
MK400
FK100 FK101
FK102
MK109
MK100 MK106
FK103
MK107
Power Card Figure 5 -1. Interfac e P C A an d P ow er P C A C onn ec tor Id en tifica tion 5-2
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5.1.1 Soft Charge and Rectifier Circuits Test B o th the rectifier and so ft charg e circuits a re tested sim ultan eo usly.The soft ch arge circuit is m ad e u p ofthe soft charge rectifier, resistor fuses and the so ft charge resistor. The rectifier circuitis m ad e up ofthe S C R /D iode m odules and includes the low er diodes o f the so ft charge rectifier. These diodes lim it the inrush cu rren t w hen ap plying pow er to the drive and serve as snub ber diod es for the S C R portion ofthe m odule.
Fuses F1, F2, F3
Itis im portantto pay close attention to the polarity ofthe m eter leads to en sure iden tification ofa fau lty com ponen tshould an inco rrectreading ap pear. P rior to m aking the test, it is necessary to ensure the so ft charge fuses,F1 ,F2 ,and F3 ,located on the softcharge card, are go od . Figure 5 -2 show s the so ftch arge card an d the location o fthe fuses. Itis forreference only.Itis notnecessary to rem ove the card to perform the tests.
5.1.1.1 Soft Charge Fuse Test U se a d igitalohm m eterto test continuity on rectifierfuses F1, F2, and F3 a t conn ector M K 10 6 o n the p ow er card. Figu re 5 -2. S oft C ha rge C ard Fu ses
NOTE If unit has fused disconnect option, make test connections L1, L2, and L3 to output (drive) side of disconnect. Do not unplug connector. 1. M easure fuse F1 from m ains inp ut L1 (R )to M K 106 p in 10 on p ow ercard. 2. M easure fuse F 2 from m ains inp ut L2 (S )to M K 106 p in 8 on p ow ercard. 3. M easure fuse F3 from m ains inp ut L3 (T) to M K 106 p in 6 on p ow ercard. A m easurem entof0 o hm s ind icates good continu ity.R ep lace any o pen fuse (infinite resistance). To rep lac e a so ft ch arg e fuse , fo llo w the so ft ch arg e disassem bly instructions in S ection 6 .
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5-3
5.1.1.2 Main Rectifier Circuit Test Part I 1. C onnectpositive (+ )m eter lead to positive (+ ) D C bus connector M K 105 (A )on p ow ercard. 2. C onnect neg ative (– )m eter lead to term ina ls L 1, L2 , an d L3 in turn. Each reading should show infinity.The m eterw illstartata low value and slow ly clim b tow ards infinity due to capacitance w ithin the drive b eing charged by the m eter.
Incorrect Reading W ith the P art Itest co nn ection , the S C R s in the S C R /D iode m odules are reverse biased so they are blocking cu rrentflow . If a short circuit exists, it w ould be possible that either the S C R s o rthe diodes in the softch arge rectifier are shorted.To isolate betw een S C R s o rthe softch arge rectifier,perform the S oftC harge R ectifier Test.
5.1.1.3 Main Rectifier Circuit Test Part II 1. R everse m eter leads by connecting neg ative (– ) m eter lead to positive (+ )D C bus co nn ector M K 105 (A )on p ow ercard. 2. C onnect positive (+ )m eter lead to L 1,L2 ,and L3 in turn. E ach reading sho uld sho w a d iode drop .
Incorrect Reading W ith the P artIItest co nn ection,even though the S C R s in the S C R /D iod e m odules are forw ard b iased b y the m eter,current w illnot flow through the S C R s w ithout providing a signal to their gates. The upper diodes in the so ft charge rectifier are forw ard biased so the m eter reads the voltag e d rop across tho se diod es. If an open reading w ere p resen t, it w ould ind icate the u pper diodes in the softcharge rectifierare open.Itcould also indicate that one or m ore of the soft charge fuses are open . It co uld furtherindicate thatthe so ftcharge resistoris open.To iso late betw een the three possibilities,perform the S oftC harge Fuse Test an d S oft C harge R ectifier Test. A shortcircuitreading indicates either one orm ore o fthe u pper softch arge rectifier diodes are shorted orthe S C R s are shorted in the S C R /D iod e m od ule. To isolate b etw een S C R s or the so ft charge rectifier,perform the S oft C harge R ectifier Test.
5-4
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5.1.1.4 Main Rectifier Circuit Test Part III 1. C onn ectpositive (+ )m eter lead to neg ative (-) D C bus connector M K 105 (B )on p ow ercard. 2. C onn ect neg ative (– )m eter lead to term inals L1, L2 and L3 in turn. Each read ing sho uld show a diod e drop .
Incorrect Reading W ith the P artIIItestco nnection,the d iodes in the S C R /D iode m odules are forw ard biased as w ellas the low er diodes in the so ft ch arge rectifier. The m eter reads the diode drops. If a shortcircuitexists itw ould be possible thateitherthe diodes in the S C R /D iod e m od ules o rthe low er diodes in the softcharge rectifierare shorted .To isolate b etw een S C R s orthe softcharge rectifier,perform the S oft C harge R ectifier Test. A lthough an open reading is p ossible, it is unlikely since that ind icates thatboth the diod es in the S C R /diode m odules and the low er diodes in the soft charge rectifier are both open . S ho uld such a resu lt occur perform the S oftC harge R ectifier Test to isolate b etw een the tw o.
5.1.1.5 Main Rectifier Circuit Test Part IV 1. R everse m eter leads by conn ecting neg ative (– ) m eter lead to negative (-)D C bus co nn ector M K 105 (B )on p ow ercard. 2. C onn ect positive (+ )m eter lead to L1 ,L2 and L3 in turn.Each reading should show infinity. Each reading should show infinity.The m eterw illstartat a low value an d slow ly clim b tow ard infinity d ue to cap acitan ce w ithin the d rive b eing charged by the m eter.
Incorrect Reading W ith the P artIV test co nn ection, the diodes in the S C R /D iode m odules are reversed biased as w ellas the low er diodes in the so ft charge rectifier. If a sh ort circuit exists it w ould be possible that either the diodes in the S C R /D iode m odules o r the low er diodes in the so ft charge rectifier are shorted. To isolate betw een S C R s o rthe softch arge rectifier,perform the S oft C harge R ectifier Test.
5.1.2 Soft Charge Rectifier Test Testing the so ft charge rectifier requires access to the so ft ch arge card co nnectors.Itreq uires rem oving the controlcard and pow er card m oun ting plate.R efer to rem ovalinstructions for softch arge card in S ection 6. D o n otrem ove the softcharge card co m pletely or unplug any co nnectors n ot called out. D oing so w illbreak the co ntinuity p ath of the se m easurem en ts an d m ay resu lt in a false interpretation ofa failure. 1. Extract soft charge card far enoug h to access connectors. 2. D isconnect D C cable at conn ector M K 3. S ince the rectifiertest requires the so ftcharge resistorto be in the circuit,verify the resistor is good before p roceeding. 3. M easure resistance b etw een p ins A and B of co nn ector M K 4 on softcharge card.Itsho uld read 2 7 o hm (+ /- 10% ).A sho rted reading ,an open reading (infinity)ora reading ofless than 24 ohm s indicates a d efective softcharge resistor. R ep lace resistorin accordance w ith disassem bly procedures in S ection 6.C ontinu e tests.
6. C onn ectpositive (+ )m eter lead to neg ative (-) M K 3 (C ).C onnect ne gative (-)m eter lead to M K 1 term inals R , S ,and T in turn. E ach reading should show a d iod e d rop . A n incorrectreading here indicates the so ftcharge rectifier is shorted .The rectifier is notserviced as a co m ponent.R ep lace the entire softcharge card in acco rdance w ith the d isassem bly procedures in S ection 6. 7. R everse m eter leads w ith ne gative (-)m eter lead to negative (-)M K 3 (C ).C onnec tpositive (+ ) m eter lead to M K 1 term inals R , S , and T in turn. E ach read ing sho uld sho w op en. Ifalltests indicate correctly w hile iso lating betw een the S C R / D iod e m od ules and the so ft charge card, the S C R /D iod e m odules are susp ect.B efore reconn ecting the cab le at M K 3, return to the M ain R ec tifier tests and rep ea t those tests. P ut the pow er card tem porarily b ack in place to retest the m ain rectifier.R eplace any defective assem blies in accordan ce w ith the disassem bly p rocedures in S ection 6.
S hould the resistorbe d efective and a rep lacem entnotreadily availab le, the rem ainder of the tests can be carried out by disconn ecting the cable atconn ector M K 4 on the softcharge card and placing a tem porary jum per across p ins A and B . This provides a p ath forcontinuity forthe rem aining tests.Ensure any tem porary jum pers are rem oved at the co nclusion o fthe tests. Fo rthe follow ing tests,set the m eter to diode check o rR x100 scale.
MK2
MK4
MK1
4. C onnect neg ative (-)m eter lead to positive (+ ) M K 3 (A )(D C ou tput to D C bu s),and con nect positive (+ )m eter lead to M K 1 term inals R ,S , and T in turn. E ach reading sho uld sho w a d iode drop . A n incorrectreading here indicates the so ftcharge rectifier is shorted .The rectifier is notserviced as a co m ponen t.R ep lace the entire softcharge card in acco rdance w ith the disassem bly procedures in S ection 6. 5. R everse m eter leads w ith positive (+ )m eter lead to positive (+ )M K 3 (A ).C onnectnegative (-)lead to M K 1 term inals R , S , and T in turn. E ach reading should show op en.
MK3
Figure 5 -3. S oft C ha rge C ard C on ne ctors
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5-5
5.1.3 Inverter Section Tests The inverter section is prim arily m ad e up ofthe IG B Ts used for sw itching the D C bus voltag e to create the output to the m otor. IG B Ts are g rou ped into m od ules com prised of six IG B Ts. D ep end ing on the size ofthe unit,on e o r tw o IG B T m od ules are p resent.The drive also has 3 snu bber capacitors on each IG B T board.
! CAUTION Disconnect motor leads when testing inverter section. With leads connected, a short circuit in one phase will read in all phases, making isolation difficult. B efore starting tests, ensure that m eter is set to diode scale. Ifrem oved previously,reinstallthe so ft charge card,interface and pow er cards.D o no t disconnect the cab le to connector M K 10 5 on the pow er card since the path for continuity w ould be broken.
5.1.3.1 Inverter Test Part I 1. C onnectpositive (+ )m eter lead to (+ )positive D C bus connector M K 105 (A )on p ow ercard. 2. C onnect neg ative (– )m eter lead to term inals U , V,and W in turn. Each reading should show infinity.The m eterw illstartata low value an d slow ly clim b tow ard infinity d ue to capacitance w ithin the drive b eing charged by the m eter.
5.1.3.2 Inverter Test Part II 1. R everse the m eter leads by co nn ecting negative (– )m eter lea d to positive (+ )D C bus connec tor M K 105 (A )on p ow ercard. 2. C onnect positive (+ )m eter lead to U , V,and W in turn. E ach reading sho uld sho w a d iode d rop.
Incorrect Reading A n incorrectreading in any invertertest indicates a failed IG B T m od ule. R ep lace the IG B T m od ule in ac cordanc e w ith the disassem bly instructions in S ection 6 .Itis further reco m m ended forunits w ith tw o IG B T m od ules thatboth m odules b e replaced even ifthe second m odule tests correctly. 5.1.3.3 Inverter Test Part III 1. C onnect positive (+ )m eter lead to the n eg ative (-)D C bus con nector M K 10 5 (B )on po w er card. 2. C onnect neg ative (– )m eter lead to term inals U , V,and W in turn. E ach read ing sho uld show a diod e d rop .
5-6
V LT is a registered D anfoss trad em ark
5.1.3.4 Inverter Test Part IV 1. R everse the m eter leads by co nn ecting negative (– )m eter lead to neg ative (-)D C bus connector M K 105 (B )on p ow ercard. 2. C onn ect positive (+ )m eter lead to U ,V,and W in turn. Each reading should show infinity.The m eterw illstartat a low value an d slow ly clim b tow ard infinity d ue to cap acitan ce w ithin the d rive b eing charged by the m eter.
Incorrect Reading A n incorrectreading in any invertertest indicates a failed IG B T m od ule. R ep lace the IG B T m od ule in acco rdance w ith the disassem bly instructions in S ection 6 .Itis furtherrecom m ended for units w ith tw o IG B T m odules thatboth m odules b e rep laced even ifthe second m odule tests correctly. Indications of a failure in this circuit IG B T failures m ay b e caused by the drive b eing exp osed to rep eated shortcircu its or ground fau lts, or by exten ded drive operation outside ofits norm aloperating param eters.Follow ing an IG B T failure, it is im portant to verify the gate drive signals are p resent and of the co rrect w aveform . S ee the dynam ic testsection on ch ecking IG B T gate drive signa ls. 5.1.3.5 Gate Resistor Test M ounted to each IG B T m od ule is an IG B T g ate resistor board co ntaining , am ong o ther co m ponents, the gate resistors for the IG B T transistors. B ased on the n ature o f the failure, a defective IG B T can prod uce good reading s from the previous tests.In nearly allcases, the failure ofan IG B T w illresu ltin the failure ofthe gate resistors. Lo cated on the gate d rive card near each of the gate signal leads is a 3 pin test co nn ector. These are lab eled M K 250, 350, 450,550,650, 750, and, ifthe drive is equipped w ith a brake option, 850. For the sake of clarity, refer to the 3 pins as o ne, tw o, and three,reading leftto right.P ins 1 and 2 ofeach connectorare in parallelw ith the gate drive signalsentto the IG B Ts.P in 1 is the sign aland P in 2 is com m on . 1. W ith oh m m eter, m easure p ins 1 and 2 o feach testco nnector.R eading should ind icate 7.77K ohm s forun its w ith sing le IG B T m odules and 3.89 K oh m s for units w ith d ualIG B T m od ules.
Incorrect Reading A n incorrectreading indicates thateitherthe gate signalw ires are notco nnected from the g ate d rive card to the g ate resistor board or the gate resistors are defective. If the resistors are defective,the IG B T m odule is likely defective as w ell.In either case,the entire IG B T m odule assem bly req uires rep lacem ent. R ep lace the IG B T m od ule in accordance w ith the d isassem bly procedures in S ection 6.
5.1.4 Brake IGBT Test This test can only be carried out on un its equipped w ith a dynam ic b rake option. If a b rake resistor is connected to term inals 81 an d 82,disco nn ect it before p roceding.U se an ohm m eter set on diod e check or R x100 scale. 1.5.1 1. C onnect positive (+ )m eter lead to brake resistor term inalR + (82). 2. C onnect neg ative (-)m eter lead to brake resistor term inalR - (81). The reading should indicate infinity.The m eter m ay startoutat a va lue and clim b tow ard infinity as cap acitan ce is charged w ithin the drive. 1.5.2 1. C onnect positive (+ )m eter lead to brake resistor term inalR - (81). 2. C onnect neg ative (-)m eter lead to brake resistor term inalR + (82). The reading should indicate a diode d rop. 1.5.3 1. C onnect positive (+ )m eter lead to brake resistor term inalR - (81). 2. C onnect neg ative (-)m eter lead to ne gative (-) D C bus connector M K 105 (B )on the pow er card. The reading should indicate infinity.The m eter m ay startoutat a va lue and clim b tow ard infinity as cap acitan ce is charged w ithin the drive.
Incorrect Reading A n inco rrect reading on any ofthe above tests indicates that the b rake IG B T is defec tive. R ep lac e the b rake IG B T in acco rdance w ith the disassem bly procedures in S ection 6 . The failure of an y IG B T m ay also lead to a failure of the gate drive circuitsupplying thatdevice.Follow ing the replacem ent ofan IG B T,alw ays ensure the g ate d rive signals are tested in acco rdance w ith the procedures in the dynam ic test section.
5.1.5 Intermediate Section Tests The interm ed iate section of the d rive is m ad e u p of the D C bus capacitors, the D C coils, an d the balan ce circu it for the capac itors. Testing the b rake IG B Ts, for units so eq uipped, w illalso be included in the interm ediate section. 1. Test for short circuits w ith ohm m eter set on R x1 00 scale or,for a digitalm eter,select diode.
2. M easure across positive (+ )D C term inal(A )an d neg ative (– )D C term inal(B )on co nnector M K 10 5 o n p ow er card.O bserve m eter polarity. 3. M eter w illstart out w ith low ohm s an d then m ove tow ards infinity as m eter ch arges cap acitors. 4. R everse m eter leads on co nnector M K 105 on po w ercard. 5. M eter w illpeg at zero w hile capacitors are discharged by m eter.M eter then b eg ins m oving slow ly tow ard tw o diod e d rop s as m eter charges capacitors in reverse direction.A lthough test does notensure capacitors are fully functional,it ensures no shortcircuits exist in interm ediate circuit.
Incorrect Reading A short circu itco uld be caused by a short in the soft charge, rectifier, or inverter section. B e su re that the test for these circuits h ave already b een perform ed successfully.A failure in one ofthese sections could be read in the interm ed iate section since they are allacross the D C bus. If a sh ort circuit is p resent, and the unit is equipped w ith a brake, perform the b rake IG B T test next. The only o the r likely cau se w ould be a defective capacitor w ithin the cap acitor ban k. There is not an effective test ofthe c apacitor bank w hen it is fully assem bled. A lthough unlikely that a failure w ithin the capacitorbank w ould notbe ind icated by a physically dam aged ca pacitor, if susp ec t, the en tire cap acitor ban k m ust be rep laced .R ep lace the capacitorban k in accordance w ith the disassem bly p roced ures in S ection 6.
5.1.6 Heatsink Temperature Sensor Test The tem perature sen sor is an N TC (negative tem perature coefficient) device. A s a result, high resistance m eans low tem perature.A s tem perature decreases,resistance increases. The pow er card reads the resistance o f the N TC sensor to reg ulate fan sp ee d an d to m onitor for over tem perature co nditions. 1. U se ohm m eter setto read ohm s. 2. U np lug con nector M K 10 0 o n interface card and m easure across cab le lead s. Th e fullrang e ofthe senso ris 78 7 o hm s to 1 05 K oh m s w here 10K ohm s equals 25°C and 78 7 ohm s equals 95°C .The low er the resistan ce, the higher the tem perature.
V LT is a registered D anfoss trad em ark
5-7
5.1.7 Fan Continuity Tests M ake all co ntinu ity checks using an ohm m eter set to R x1 scale. D igitalor analog ohm m eter can b e u sed . To aid in m aking the m easurem ents, unplug the connector C N 2 from its m ate.C N 2 term inals corresp ond to the term inal nu m bers lab eled on the transform er. 5.1.7.1 C he cking C ontinu ity of C onne ctions For the follow ing tests, read the plug end of co nne ctor C N 2 that is not connected to the tran sform er. 1. M easure from L3 (T) to C N 2 term inal1. A read ing of< 1oh m sho uld be ind icated .
5.1.7.3 O hm Test of Fa ns 1. M easure betw een term inals 11 and 13 o fpo w er card conn ector M K 107 .A reading of20 ohm s should be ind icated . 2. D isconnect spad e co nnectors from do or fan and rep eat m easurem ent.A read ing of 21 ohm s should be ind icated . 3. R ead term inals ofdoor fan w ith w ires disconnected .A read ing of40 0 o hm s shou ld be indicated. 4. R econne ct w ires to do or fan.
2. M easure from L2 (S )to C N 2 term inal3. A reading of< 1 o hm sho uld be ind icated . 3. M easure from C N 2 term inal2 to term inal12 o f po w er card con nector M K 10 7. A read ing of < 1 oh m should be ind icated .
Incorrect Reading A n inco rrectreading w ould indicate a fau lty cab le co nnection. R ep lace the cab le assem bly. 5.1.7.2 O hm Test of A utotran sform er For the follow ing tests, read the plug end of co nne ctor C N 2 that is connected to the tran sform er. 1. M easure betw een C N 2 term inals 1 and 3. A pp roxim ately 15 ohm s shou ld be read .
Incorrect Reading A n incorrect reading of one o r both of the fan s indicates a defective fan.R eplace the d efective fan. 5.1.7.4 Testing Fan C ap ac itor 1. Fan cap acitor is m ounted to fan enclosure. To gain access to capacitor,rem ove inp ut term inal plate in accordan ce w ith the disassem bly procedures in S ection 6. 2. Ifsusp ected ,test capacitor w ith a m eter capable ofrea ding capacitance.Verify reading w ith capacitance value stam ped on bod y of capacitor.
2. M easure betw een C N 2 term inals 1 and 2. A pp roxim ately 12 ohm s shou ld be read . Fan transformer
3. M easure betw een C N 2 term inals 2 and 3. A pproxim ately 4 ohm s should b e read .
CN2
Fan fuse
Incorrect Reading A n inco rrectreading w ould indicate a defective fan transform er. R ep lace the fan tran sform er. W hen finished ,be sure to reco nnect C N 2.
Figu re 5-4. Fa n Tran sform er an d Fu se Lo cation
5-8
V LT is a registered D anfoss trad em ark
5.2 DYNAMIC TEST PROCEDURES R efer to term inallocations in Figure 5-5 forperform ing dynam ic test procedures.
NOTE Test procedures in this section are numbered for reference only. Tests do not need to be performed in this order. Perform tests only as necessary.
! DANGER Never disconnect input cabling to drive with power applied due to danger of severe injury or death.
! WARNING Take all necessary safety precautions for system start up prior to applying power to drive.
Main 3-phase AC power to drive
3-phase output to motor
DC bus/loadsharing connections
Brake resistor connection
Figure 5-5. D rive P ow er Term ina ls
V LT is a registered D anfoss trad em ark
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5.2.1 No Display Test A drive w ith no disp lay indication can be the result ofseveral causes. It is first im portant to verify tha t there is no disp lay w hatsoever. A single ch aracter in the disp lay o r a dot in the upper co rner ofthe disp lay indicates a com m unication error an d is typically caused by an option card not being properly installed. Typ ically under this condition the green pow er on LE D is illum inated. Ifthe LC D display is com pletely dark and the green pow er on LED is n otlit,proceed w ith the follow ing tests. First test for proper inputvo ltage
5.2.1.1 Input Voltage Test
! CAUTION
Open (blown) input fuses or tripped circuit breakers usually indicate a more serious problem. Prior to replacing fuses or resetting breakers, perform static tests described earlier in this section. If the Input Voltag e Test w as succ essfulch eck for voltag e to the co ntrolcard.
5.2.1.2 Basic Control Card Voltage Test 1. U se voltm eter to m easure 24 VD C control voltage at term inal12 w ith respec tto term inal 20 .M eter should read b etw een 21 and 2 7 V D C .
1. A pply po w er to d rive. 2. U se D V M to m easure inp ut line voltage betw een drive inputterm inals in turn:
If an external 24 VD C supply is used for control voltage, it w ould be likely for sw itch 4 on the c ontrolcard to be open. This open s the co m m on co nn ection to term ina l20. If this is the case, m easure term inal12 w ith resp ect to term inal39.
L1 to L2 L1 to L3 L2 to L3 A ll m easurem ents m ust be w ithin the range of 34 2 to 52 8 VA C (or 34 2 to 55 0 VA C for VLT 50 00 ).R ead ings ofless than 342 V A C ind icate p roblem s w ith the inp ut A C line voltag e. In addition to the actualvoltage reading, the b alance o f the voltag e b etw een the p hases is also im portant.The drive can operate w ithin specifica tions as long as the p hase im balance is not m ore than 3 % . D an foss calcu lates line im balan ce per an IE C sp ecification. Im balanc e = 0.67 X (Vm ax –V m in) / Vavg Fo rexam ple,ifthree phase reading s w ere taken and the results w ere 500 VA C ,478 .5 V A C ,and 4 78.5 V A C ;then 500 VA C is Vm ax,47 8.5 V A C is V m in,and 48 5.7 VA C is V avg, resulting in an im balance o f3% . A lthough the d rive can operate athigher line im balan ces, the lifetim e o f co m ponents, such as D C bus cap acitors, w illbe shortened. Inco rrec tR ea d ing A n inc orrect reading here req uires that the m ain supply b e investigated further.Typicalitem s to ch eck w ould be: O pen (blow n)inputfuses o rtripped circu itbreakers O pen disconn ects orline side contactors P roblem s w ith the p ow er distribution system
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A n inco rrect rea ding here could indicate the supply is b eing load ed dow n b y a faultin the custom er co nn ections. U np lug the term inalstrip and repeat the test.Ifthis testis successful than con tinue. R em em be r to check ou t the custom er co nnections.Ifstillunsuccessfulproceed to the S w itch M ode P ow erS up ply (S M P S )test. 2. M easure 1 0 V D C controlvoltage at term inal50 w ith respectto term inal55.M eter sho uld read betw een 9.2 and 1 1.2 V D C . A n inco rrect rea ding here could indicate the supply is b eing load ed dow n b y a faultin the custom er co nn ections. U np lug the term inalstrip and repeat the test.Ifthis testis successful than con tinue. R em em be r to check ou t the custom er co nnections.Ifstillunsuccessfulproce ed to the S M P S test. A co rrectreading ofboth co ntrolcard voltag es w ould indicate the L C P or the control card is d efective. R ep lace the LC P w ith a know n g ood one . If the p roblem persists rep lace the co ntrolcard in acco rdance w ith the disassem bly p roc ed ures in S ection 6.
5.2.2 Switch Mode Power Supply (SMPS) Test
5.2.3 Zero DC Bus Voltage Test
The S M P S derives its pow erfrom the D C bus.The firstind ication that the D C bus is charged is the D C bus charge ind icator being lit.This LED how evercan be litata vo ltage stillto low to enab le the pow er sup plies.
If no voltag e is present at pow er card co nn ector M K 105 (A ) and (B ),check the cond ition ofthe D C pow er sup ply fuse.The D C pow er sup ply fuse is loc ated beneath the pow er card. It can be tested w ithout disassem bling the u nit.
First test for the p resence ofthe D C bus. 1. U sing a voltm eter,read D C bus vo ltage at po w er card con nector M K 10 5 (A )w ith respect to M K 105 (B ).M eter should indicate approxim ately 47 0 V D C to 73 0 V D C ,depen ding on line voltage supplied to drive. 2. Ifvoltage is correct proceed to set 3.Ifvoltage is present but ou tof range,proceed to D C U nd er Voltage test. Ifvoltage is at zero,proceed to Zero D C B us V oltage test. 3. Testrem aining pow ersupplies.Insertsignaltest board into interface card co nn ectorM K 104 4. C onnect neg ative (-)m eter lead to term inal4 (co m m on)ofsignalboard.W ith p ositive (+ ) m eter lead ch eck the follow ing term inals on signalboard. Term inal 11 12 23 24
S up ply + 18V -18V + 24V + 5V
V oltage R ange 16.5 to 19.5 V D C -16.5 to -19.5 VD C 23 to 25 V D C 4.75 to 5.25 V D C
In addition,the signaltestboard co ntains three LED indicators that indicate the presen ce ofvoltag e as follow s:
1. R em ove pow er to d rive and ensure D C bus is fully disch arged by m easuring voltag e atpow er card co nn ector M K 105 (A )w ith resp ectto M K 105 (B ).
! CAUTION If DC power supply fuse is open (blown), it is not possible to detect the presence of bus voltage at these terminals. If uncertain, wait 15 minutes to allow DC bus to fully discharge. 2. W ith o hm m eter seton diod e scale or R x100 , m easure from po w er card co nnector M K 105 (A ) to any bus b ars com ing from D C ind uctor.B us bars are visible atlow er ed ge and ben eath po w ercard m ou nting bracket.D epend ing on bus bar read,look fora diode drop or co m plete sh ort.In either case this indicates a fuse is in the circuitproviding a path for continuity.A n open reading indicates o pen fuse. Ifthe fuse is o pen, it indicates a failure ofthe pow er su pplies on the p ow er card . Th e p ow er card and fuse req uire rep lacem ent.Ifthe fuse checks good,there m ay b e a problem w ith the softcharge circuitry.P roceed to the static checks of the softcharge and rectifier circuits earlier in this se ction.
R ed L E D + /- 18V D C supp lies present Y ellow LE D +2 4V D C supp ly present G reen LED +5 VD C supply present The lack o fany one o fthese pow er supplies ind icates the low voltag e supplies o n the pow er card are d efective.This assum es of course that the prop er D C bus voltage w as read at pow er card connectorM K 105 (A )and (B ).R ep lace the pow er card in acco rdance w ith the disassem bly procedures in S ection 6 .
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5.2.4 DC Under Voltage Test
5.2.5 Input Phase Imbalance Test
The initialcharge o f the D C bus is accom plished by the soft ch arge circu it.Ifthe D C bus vo ltag e is b elow norm alitw ould indicate that either the line vo ltage is out of tolerance or the so ft charge circuit is restricting the D C bus from charging. C onduct the input voltage test (5.2.1.1) to ensure the line vo ltage is correct.
Theoretically,the curren tdraw n on allthree inputphases should be equal. S om e im balance m ay be seen, how ever, due to variations in the p hase to pha se input voltag e an d, to som e degree,single phase loads w ithin the drive itself.
Ifexcessive inputpow er cycling has occurred ,the P TC resistors on the soft ch arge ca rd m ay b e restricting the b us from ch arging.Ifthis is the case, expect to read a D C bus vo ltag e in the area o f50 V D C . 1. C heck D C bus voltage b y reading po w er card con nector M K 10 5 (A )w ith respectto M K 10 5 (B ).Ifverified,rem ove pow er from drive and allow itto co olforap proxim ately 20 m inutes. 2. R eap ply pow er to drive after 20 m inutes and recheck D C bus vo ltag e. Ifvoltag e rem ains,a shortcircuitm ay e xist w ithin the interm ediate circuitpreventing itfrom charging.P roceed to static checks (5.1)earlier in this section.
A currentm easurem entofeach phase w illrevealthe balanced condition ofthe line. To obtain an accurate reading, it w illbe necessary forthe drive to run atits rated load ornotless than 40% load. 1. P erform inputvoltag e testpriorto ch ec king cu rrentin acco rdance w ith procedure. Voltage im balances w illautom atically resultin a co rresp ond ing currentim balance. 2. A pply pow er to d rive and place itin run. 3. U sing a clam p-on am p m eter (analog preferred ), read cu rrent on each ofthree input lines at L1(R ),L2(S ),and L3(T). Typically,the currentshould notvary from phase to phase b y m ore than 5% .S hould a g reater curren tvariation exist,itw ould indicate a possible p roblem w ith the m ain supply to the d rive ora problem w ithin the drive itself. O ne w ay to determ ine ifthe m ains supply is atfau ltis to sw ap tw o of the incom ing phases. Th is assum es that tw o p hases read one currentw hile the third is m ore than 5% different.Ifall three phases are d ifferentfrom one another,itw ould be difficult to determ ine w hich lead s to sw ap . 4. R em ove pow er to d rive. 5. S w ap phase thatap pears to be incorrect w ith on e ofother tw o p hases. 6. R eapply pow er to drive and place itin run . 7. R epeat current m easurem ents. Ifthe phase im balance m oves w ith sw ap ping the leads,then the m ain supply is suspect.O therw ise,itm ay indicate a problem w ith the gating of the S C R /D iod e m od ules. Th is m ay be d ue to a d efective S C R /D iode m odule o r in the gate signals from the pow er card to the m odule, including the possibility o fthe w ire ha rness from the p ow er card to the S C R gates. Fu rther tests on the proper gating ofthe S C R s req uires an oscillosco pe eq uipped w ith c urrent probes. P roceed to testing the inp ut w aveform and inp ut S C R /diod e m od ule in acco rdance w ith their procedures.
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5.2.6 Input Waveform Test Testing the curren t w aveform on the input of the d rive can assist in troubleshooting m ains p hase loss conditions or suspected prob lem s w ith the S C R /D iod e m od ules.P hase loss caused by the A C supply can b e easily detected .In addition, the rectifier section is controlled by SC R /D iode m odules.S hould on e ofthe S C R /D iod e m od ules beco m e defective or the g ate signalto the S C R lost,the d rive w illrespond the sam e as loss ofone ofthe phases. The follow ing m easurem en ts req uire an o scilloscope w ith voltag e an d currentprobes. U nder no rm aloperating co nd itions,the w aveform ofa sing le phase ofinp utA C voltag e to the drive appears as in Figure 5 6.
Figu re 5-6. N orm alA C Inp ut V oltag e W aveform The w aveform sho w n in F igure 5 -7 rep resents the inp utcurrent w aveform for the sam e phase as Figu re 5-6 w hile the drive is running at40 % load.Th e tw o positive and tw o negative jum ps are typ icalofany 6 diode bridge.Itis the sam e for drives w ith S C R /D iode m odu les.
CONTINUED ON NEXT PAGE Figure 5 -7. A C Inp ut C urren t W aveform w ith D iod e B rid ge V LT is a registered D anfoss trad em ark
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W ith a phase loss, the curren t w aveform of the rem aining phases w ou ld take o n the ap pearance sho w n in Figu re 5-8.
Figure 5-8. Inp ut C urren t W aveform w ith P ha se Lo ss
A lw ays verify the co ndition ofthe inputvoltag e w aveform before form ing a conclusion. The curren t w aveform w ill follow the voltage w aveform .Ifthe vo ltag e w aveform is inco rrectproceed to investigate the reason for the A C supply p roblem . If the voltag e w aveform on allthree p hases is correctbutthe current w aveform is not then the input rectifier circuit in the drive is susp ect.P erform the static so ftcharge and rectifiertests and also the d ynam ic S C R /D iod e m od ule test.
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5.2.7 Input SCR/DIODE Module Test The S C R /D iod es (S C R s)can be d isabled by the drive for various reasons.C heck the follow ing before m aking m ore com plicated tests.
W ith a reading of0 V D C and proper line pow er ap plied to the drive, it w ould be likely that the input at pow er card term inal FK 10 2 h as cau sed the S C R s to b e d isabled . G iven the co nn ection atFK 102 has been verified the co ntrolcard w ould be suspect.C he ck the inrush signa las follow s.
The S C R s can be d isab led as a result of an inp ut, or lack o f inp ut, at pow er card co nn ector FK 102, the external brake tem perature sw itch.U nless used as an inp ut,a jum per m ust be placed betw een term inals 104 and 10 6 o fFK 10 2
8. C onn ectpositive (+ )m eter lead to term inal7 of signalboard.
The S C R s are g ated in seq uence w ith the m ain sup ply.Verify that the voltage reference signalis correct as follow s.
A reading of0 VD C indicates the inrush signalis active an d the S C R s are b eing gated .A reading of5 V D C ind icates the inrush signalis inactive and the S C R s are n ot gated .
1. U sing a volt m eter,m easure p hase to ph ase A C line voltag e at Term inals R ,S ,an d T ofpow er card conn ector M K 106 .
W ith a reading of5 V D C and proper line pow er ap plied to the drive,it w ould be likely that the controlcard is defective.
2. M easurem ents should correspo nd w ith m easurem ents called outin the Inp ut Voltag e Test (5.2.1.1). A n inco rrect reading at M K 106 w ith a correct input voltag e m ay indicate a problem in the so ftcharge card,the conn ecting cable or an incorrect co nn ection atFK 103. 3. A tFK 10 3, jum perbetw een term inals 100 an d 10 2, and 10 1 an d 1 03 .W ith jum pers an inco rrectvoltag e atM K 106 indicates softch arge card is susp ect.P erform softch arge an d rec tifier tests in the static test section. Ifthe above tests revealno abnorm alities, itis furtherpossible tha t the inrush signal has not been en ab led by the co ntrol card.U sing the signaltestcard,verify the inrush signalis p resent an d the S C R disable signalis at the co rrect voltag e level as follow s. 4. Insertsignaltest board into interface card connectorM K 104.
The inrush signalis also deactivated by the co ntrolcard anytim e an over tem perature cond ition exists b ut tha t should be indicated by an A larm 29 and a differentgroup oftroubleshooting procedures w ou ld be in o rder. If the controlcard is susp ect, replace it in accordance w ith the disassem bly p rocedures in S ection 6. S hould the above tests check correctly, proceed to testing the S C R gate signals. To view the g ate signals an oscillosco pe and a currentprobe are required. 9. R un drive w hile un der som e d egree o fload.A t least a 3 0% load m ay b e req uired to co nsisten tly see g ate signals produced since S C R s are only gated w hen D C bus falls below peak ofline. 10.C onn ect current probe, in turn,to each (+ ) positive S C R gate w ire (w hite leads)m arked R , S ,and T at po w er card co nnector M K 100 . Th e w aveform sho uld ap pear as in F igu re 5 -9.
5. C heck S C R disable signal. 6. U sing a vo lt m eter, co nn ect neg ative (-)m eter lead to term inal4 (co m m on)oftestboard.
CONTINUED ON NEXT PAGE 7. C onnect positive (+ )m eter lead to term inal19 of signalboard. A reading of0 V D C ind icates the S C R s have b een disab led .A reading of0.6 to 0.8 V D C ind icates the S C R s are active and should b e gated .
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5.2.8 Output Phase Imbalance Test C hecking the b alan ce ofthe d rive o utput voltag e and cu rren t m easures the electricalfunctioning betw een the d rive an d the m otor.In testing the p hase-to-phase output,both voltag e and cu rren tare m onitored .Itis recom m ended thatstatic tests on the inverter section of the drive be conducted prior to this procedure.
Figu re 5-9. S C R G ate S ign al The cu rrent pulse sho uld have a w aveform as sho w n.
A1 > 1.1 A A2 > 0.40 A
Ifthe vo ltage is b alanced butthe currentis not,this indicates the m otoris draw ing an une ven load .This co uld be the resu lt ofa defective m otor,a poorco nn ection in the w iring betw een the drive and the m otor, or, if applicable, a defective m otor overload . Ifthe outputcurrentis u nbalanced as w ellas the voltag e, the drive is n otgating the outputproperly.This could be the result ofa defective pow er card,conn ections betw een the gate drive card and IG B Ts, orthe o utputcircuitry ofthe d rive im properly connected.
T1> 300 µs G iven all the o ther tests above w ere successful, a m issing gate signalindicates the pow er card is d efective.R ep lace the pow er card in accordance w ith the disassem bly proced ures in S ection 6.
NOTE Use an analog volt meter for monitoring output voltage. Digital volt meters are sensitive to waveform and switching frequencies and commonly return erroneous readings.
A distorted signal m ay b e d ue to a d efective g ate o n that particu lar SC R that is load ing dow n the supply. R ep lace the S C R /D iod e m od ule w hich corresp on ds to the incorrect gate signalreading.
The initial test can be m ad e w ith the m otor co nn ected and running its load. If susp ect read ings are recorded then the m otor leads m ay have to be d isconn ected to furthe r isolate the prob lem . 1. U sing a volt m eter,m easure A C ou tput voltage at drive m otor term inals 9 6 (U ),97 (V ),an d 98 (W ). M easure phase to p hase checking U to V, then U to W , and then V to W . A llthree reading s should be w ithin 8 VA C ofeach other. The actualvalue ofthe vo ltag e d ep ends o n the sp eed the d rive is running at.The vo lts/hertz ratio is relatively linear (exceptin VT m od e)so at60 H z the voltage shou ld be approxim ately equal to the line voltage applied.A t30 H z itis abouthalfofthatand so on forany otherspeed selected .The exact voltag e reading is less im portantthan balance betw een phases. 2. N ext m on itor three ou tput phases at drive m otor term inals 96 (U ),97 (V ),an d 98 (W )w ith clam p on am m eter.A nalog device is p referred .To achieve accurate reading ,run drive above 40 H z (as this is n orm ally the frequency lim itation of such m eters.) Th e o utput current sho uld be b alanced from phase to phase and no phase sho uld be m ore than 2 to 3% different from another.Ifthe above tests are successful,the drive is o perating norm ally.
CONTINUED ON NEXT PAGE
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3. Ifa greater im balan ce exists than described ab ove, disconnect m otor lead s an d rep eat voltag e balance test.
P rior to beg inning the tests, ensure that pow er is rem oved from the un it and that the D C B us c ap acitors have b een discharged .
S ince the current w ill follow the voltage, it is necessary to isolate betw een a load prob lem and a drive p rob lem .S ho uld a voltag e im balance in the output be detected w ith the m otor disconnected,itis necessary to test the gate drive circuits for proper firing.P roceed to the g ate d rive signals test (5.2.9). Ifthe voltag e w as balanced but the currentim balanced w hen the m otor w as conn ected , then the load is suspect. There co uld be a faulty conn ection b etw een the drive and m otor or a d efect in the m otor itself. Look for bad co nnections at an y jun ctions o fthe output w ires includ ing co nne ctions m ad e to co ntactors and over load s. A lso, check for burned or open co ntacts in su ch devices.
C heck for the presence ofD C bu s voltage by m easuring po w er card connector M K 10 5 (A ) w ith resp ect to M K 10 5 (B ). Th e voltag e should be zero (0)before proceed ing. 1. Follow procedure in S ection 6 forsoftch arge card rem ovaland disengag e so ftcharge card far enou gh to d isconnect cab le plug ged into M K 3. 2. C onn ectone end of TestC able into M K 3. 3. R einstallsoftch arge card. 4. D isconnectconnectors M K 100 and M K 105 on po w ercard. 5. C onnect free en d of TestC able into M K 10 5.
5.2.9 IGBT Gate Drive Signals Test This p rocedure tests the g ate d rive signals atthe o utputofthe gate drivercard justpriorto them being delivered to the IG B T’ s. A sim ple test to ch eck for the p resen ce of the g ate signals can be p erform ed w ith a D VM ,ho w ever to actually check the w aveform s an oscillosco pe is req uired .
! CAUTION Disable DC bus when performing this test with Test Cable p/n 176F8437. Failure to do so could result in damage to drive if probe is inadvertently connected to wrong pins. Additionally, AC mains bus bars are in close proximity to these test points. Exercise caution when working close to high voltage components.
6. C onn ectS C R gate sho rting plug (includ ed w ith testcable 1 76F8437)into cab le thatw as rem oved from M K 100. Lo cated on the gate d rive card neareach gate signallead is a 3 pin test co nnector. Th ese are lab eled M K 25 0, M K 35 0, M K 45 0,M K 55 0,M K 65 0,M K 75 0,and ,ifthe d rive is equipped w ith a b rake o ption ,M K 85 0. For the sake of clarity, refer to the 3 pins as o ne, tw o, and three,reading leftto right.P ins 1 and 2 ofeach connectorare in parallelw ith the gate drive signalsentto the IG B Ts.P in 1 is the sign aland pin 2 is com m on . 7. R econn ect A C po w er to d rive. 8. In stop m od e,ap ply po w er to d rive. 9. M easure pins 1 and 2 o feach test connector. E ach read ing sho uld be ap proxim ately – 9 VD C , indicating allIG B Ts are tuned off. 10.A pp ly run com m and to d rive and 30 H z reference.
CONTINUED ON NEXT PAGE MK750 MK850 (brake)
MK250
MK350 MK450
MK102 (U) MK105 (brake option)
MK550 MK650
MK103 (V)
MK104 (W)
Figu re 5 -10 . G ate D rive C ard Test C on ne ctors V LT is a registered D anfoss trad em ark
5-17
11. Ifusing a D VM , m easure p ins 1 and 2 o feach co nn ector. W aveform to IG B Ts is a square w ave that go es positive to 1 4 V D C and negative to -9 VD C .A verage voltag e read by D VM should b e 2.2 to 2.5 V D C . W hen u sing an oscillosco pe, the reading s sho uld ap pear as below :
2 V/D iv 100 us/div U nit in run at 10 H z.
Figure 5-11 . G ate S igna lW ave form
A n incorrect reading ofa g ate signalindicates the g ate d rive card is defective or the signalhas been lost prior to it arriving at the gate card.The gate signals can then be checked w ith the signaltest board to verify their presence from the control card to the pow er card as follow s. 12. Insertsignaltest board into interface card connectorM K 104. 13. W ith scop e p rob e g roun d conn ected to term inal4 (co m m on)ofsignalboard,m easure six gate signals atsignalboard term inals 25 throu gh 30 .
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14 . P lace d rive in run at 30 H z. The w aveform shou ld ap pear as below :
10 V /div 10 0us/div U nit in run at 30 H z
Figure 5-12 . G ate S igna lW ave form 15. U sing a D VM ,again check these sam e signal board term inals.D V M sho uld read 2.2 to 2.5 VDC. A n inco rrect reading ofa g ate signalindicates eitherthe p ow er card is d efective orthe signalhas b een lost priorto arriving at the pow er card. There is no test to verify the signals d irectly out ofthe controlcard.The pow er card w ould be suspected if a single gate signal is inco rrec t. The controlcard w ould be susp ectifallsix signals are incorrect.R eplace the corresp onding card in accordance w ith the disassem bly procedures in S ection 6.
V LT is a registered D anfoss trad em ark
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5.2.10 IGBT Switiching Test U sing the test cab le w hile the d rive is p ow ered an d the D C b us is d isab led , a sim p le test ca n b e m ad e to d eterm ine if the IG B Ts are ac tually turning on. B efore proceed ing,verify that the D C bus is in factdisabled . 1. D isconnect cable from conn ector M K 10 5 o n pow er card. W ith a volt m eter, m easure betw een w hite lead ofcable disco nn ected from M K 10 5 and ou tput term inals U ,V,and W in turn. S w itch b etw een A C and D C scales. Voltag e should read nearly zero. 2. M easure b etw een b lack lead of sam e cab le and the o utput term inals U ,V, and W in turn.Voltag e should read nearly zero. W ith D C bu s disabled , proceed using a D V M set on diod e scale. 1. W ith drive in a stop m od e, co nn ectpositive (+ ) m eter lead to b lack lead o fM K 105 cab le disconnected from pow er card. 2. In turn connec t neg ative (-)m eter lead to drive output term inals U ,V,an d W .M eter should ind icate a diode drop. 3. Leaving positive m eter lead co nnected to cable M K 10 5, run drive at 30 H z. 4. In turn, ag ain co nnect neg ative (-)m eter lead to drive output term inals U ,V,and W .M eter should indicate effectively a sh ortcircuitor around a 0.035 diode d rop w hich ind icates low er IG B Ts are turned on a nd shorting m eter to neg ative bus.
NOTE Some voltage leakage within unit may cause meter to indicate a small negative voltage drop. 5. R ep eat testfor positive (+ )or up per IG B Ts. 6. W ith drive in a stop m ode, co nn ect negative (-) m eter lead to w hite lead ofM K 105 cab le disconnected from pow er card. 7. In turn,connect positive (+ )m eter lead to drive output term inals U ,V,an d W .M eter should ind icate a diode drop. 8. Leaving negative m eter lead conn ected to cab le M K 10 5, run drive at 30 H z.
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9. In turn,ag ain connect positive (+ )m eter lead to drive outputterm inals U ,V,an d W .M eter should indicate effectively a sh ortcircuitor arou nd a 0.035 diod e d rop w hich ind icates upper IG B Ts are turne d on an d shorting m eter to positive bus.
NOTE Some voltage leakage within unit may cause meter to indicate a small negative voltage drop. Incorrect Reading A n incorrect reading ind icates som e of the IG B Ts are not turning on. R ep lace the IG B T m odule in accordance w ith the disassem bly instructions in S ection 6.
5.2.11 Brake IGBT Test U se the signaltest bo ard to test the operation ofthe dynam ic brake IG B T an d gate drive circu itry. The follow ing procedure can be used to force the brake circuit to activate for testing. 1. C onnect signaltestboard to con nector M K 10 4 on co ntrolcard. 2. S et voltag e testsw itch to O N position. 3. Turn p oten tiom eter on testboard untilbrake circuit activates. This causes b rake IG B T to turn on and offat ap proxim ately 2 K H z.D uty cycle (pulse w idth)increases as potentiom eteris increased. 4. M easure w ith o scilloscop e or D VM at term inal 13.Term inal13 rep resen ts gate signalto brake IG B T.This shou ld be 4.04 VD C w hen brake is O FF and drop to zero w hen b rake is O N . 5. M easure w ith o scilloscop e or D VM at term inal 14.Term inal14 is a logic level(5V)signal rep resenting voltag e across brake IG B T.This should m easure 5.1 V D C w hen b rake is O FF and drop to zero w hen b rake is O N .
Incorrect Reading Ifthe signalon term inal13 is n ot correct, first check that the drive is correctly program m ed fordynam ic b raking (param eters 400 - 404).Ifthe p rogram m ing is correct,rep lace the control card in acco rdance w ith procedures in S ection 6. Ifthe signalon term inal13 is correctbutthe signalon term inal 14 is no t, the brake IG B T gate signal m ust be checked to determ ine w hether the faultlies in the IG B T or the gate driver card.S ee G ate D rive S ignalTests (5.2.9).
5.2.12 Current Sensors Test The curren tsensors are H alleffectdevices that send a scaled dow n signalofthe actualoutputcurrentw aveform to the pow er card for m onitoring and processing m otor co ntrol data. A defective current sen sor can cause erroneous ground fau lts and overcurrent trips. In su ch instances, the fault w illusu ally only occur at higher load s. A coup le of sim ple checks can b e m ad e to d eterm ine the status ofthe sen so rs. 1. A pply po w er to d rive. 2. Ensure that m otor check,pre-m agnetizing ,D C ho ld,D C brake,or other param eter setup s are disabled that create a holding torque w hile at zero sp eed.C urrentdisplayed w illexceed 1 to 2 am ps ifsuch param eters are n otdisab led . 3. R un drive w ith a zero sp eed reference.N ote outputcurrentreading in disp lay. D isp lay sh ould ind icate approxim ately 1 to 2 am ps. If the curren t is grea ter than 1 to 2 am ps an d a curren t producing param eter is not ac tive, the test w illto be m ad e ag ain w ith the m otorleads d isco nn ected . 4. R em ove pow er from drive.M onitor D C bus voltage at pow er card connector M K 10 5 (A )and (B )to ensure bus is fully discharged. 5. R em ove o utput m otor lead s from term inals U ,V, an d W .
Testing cu rren tfee dback w ith the signaltestboard. 8. R em ove pow er to drive.E nsure D C bus is fully discharged. 9. Installsignaltest board into interface card connectorM K 104. 10 . R eap ply pow er to d rive. 11 . U sing a D V M , co nnect negative (-)m eter lead to term inal4 (co m m on)ofsignaltestboard. 12 . R un drive w ith a zero sp eed reference. 13 . In turn m easure A C voltag e at term inals 1, 2, an d 3 ofsignaltestboard. These term inals co rrespond w ith currentsen soroutputs U ,V, an d W , resp ectively. Exp ect a reading near zero vo lts but no greater than 1 5m v. If the co ntrolcard param eters are setup to provide holding torque w hile at zero speed,the currentdisp layed w illbe greater than exp ected .To m ake this test disab le su ch param eters. The c urrent senso r feedback signalat this p oint in the circuit w illread approxim ately 400 m v at10 0% drive load so any reading ab ove 1 5m v w hile the drive is at zero speed has a negative effect on the w ay the drive interprets the feedback signal. A reading ofgreaterthan 1 5m v sug gests thatthe corresp ond ing cu rren tsensorbe rep laced .S ee the d isassem bly instructions in S ection 6.
6. A pply po w er to d rive. 7. R un drive w ith a zero sp eed reference.N ote outputcurrentreading in disp lay.D isp lay should indicate less than 1 am p. If an inco rrect reading w as obtaine d from the ab ove tests, further tests ofthe currentfeed back signals are required using the signaltest bo ard.
V LT is a registered D anfoss trad em ark
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5.2.13 Fan Tests The fan co ntrolcircu it is m ad e u p ofthe fan tran sform er and the controlcircuitlocated on the p ow er card along w ith control signals forO N ,O FF,an d sp eed co ntrolfrom the co ntrolcard. S ince the fan s d o not necessarily run at all tim es, see the desc ription of co oling fan s o peration un der sequen ce of operation in S ec tion 2. 5.2.13.1 S up p ly V oltag e S upply vo ltag e for the fan s is from the soft charge card to pow er card co nn ector M K 106.First verify the su pply voltag e is p resentas follow s. 1. W ith a voltm eter,m easure A C ph ase to p hase voltage at R , S , and T of pow er card connector M K 106 .Itsho uld eq ualm ain sup ply voltage applied to drive. 2. Ifvoltage is notpresent,ensure p roper line voltage is applied to drive.C onductInputVoltag e test(5.2.1.1). 3. Ifline voltage is presentatinputofdrive butnot at M K 106 o fpow er card,co nd uct static test of so ftcharge fuses (5.1.1).
2. Ifvoltage is correct,check fan voltage b eing supplied to fan s them selves. Voltag e can be read atpow er card c onnector M K 10 7 p ins 8 an d 11 w ith resp ect to pin 1.Voltag e at pins 8 and 1 1 correspon d to fan's com m anded speed: 20 0 V A C for low speed and 230 VA C for high speed. If the correct vo ltage is available but the fan is not running, thatparticular fan is defective.Ifno vo ltage is available,verify that the fans sh ould be running. If so , the p ow er ca rd is defective. R ep lace the fan or pow er card in accordance w ith the disassem bly instructions in S ection 6. 5.2.13.3 Fan C ontrolC ircu it To verify that the fan controlcircuit is receiving appropriate co m m ands from the co ntrolcard, the signaltest board can be used to verify those signals. 1. R em ove po w er from drive and allow D C bu s to fully d ischarge. 2. Installsignaltest board into interface connector M K 1 04. 3. R eap ply pow erto drive.
4. Ifvoltage is p resent at M K 106, check vo ltag e at fan transform er read from co nn ectorC N 2 located near transform er. W ith a volt m eter, read A C voltage atC N 2 pins 1 and 3. Voltage sho uld co rresp ond to m ain A C line voltag e applied to drive. 5. Ifvoltag e is not presen t,en sure jum pers are in place atpo w er card con nector FK 10 3. O therw ise con nec tan externalsou rce of pow er to term inalFK 103 forfan supply voltag e. Ifthe jum pers are in place or an auxiliary su pply is connected and pow ered but no voltag e is p resent at the fan transform er co nn ector C N 2, the pow er card is likely d efective. R ep lace the pow er card in accordance w ith the disassem bly instructions in S ection 6. 5.2.13.2 Tran sform er O utp ut Ifthe ap propriate voltag e is p resentat C N 2 pins 1 an d 3,next ch eck the outputofthe tran sform er.P riorto m aking this test, ensure the fan transform er fuse located nextto the transform er is goo d. 1. W ith a volt m eter, m easure A C voltage from C N 2 term inal1 to term inal2.Voltag e should eq ual66% ofm ain A C sup ply voltag e ap plied to drive (or that ofauxiliary supply).Ifvo ltage is incorrect,replace fan transform er.
5-22
V LT is a registered D anfoss trad em ark
4. C onn ect neg ative (-)m eter lead ofa voltm eter to signalboard term inal4 (co m m on). 5. W ith positive (+ )m eter lead ch eck signalat term inal6 ofsignalboard. M etershould read zero (0)volts w ith fans co m m an ded to run ,5 V D C ifcontrolcard fans off. 6. V erify cooling fans sequence ofoperation to en sure they should be running.In ad dition,signal board co ntains a fan test sw itch.W hen sw itched on fans should startand run at high speed. The signals atterm inals 5 and 10 ofthe signalboard determ ine fan speed.S ee S ection 7 form ore o n tho se signals.In ad dition, ifa h eat sink overtem perature trip has occurred,the fans w ill autom atically be sw itched to h igh sp eed. G iven the factthatthe fans should be running,ifthe signalat term inal6 is correctand the fan test sw itch activates the fan, the co ntrol card is d efective. O therw ise the pow er card is defective. R ep lace the ap propriate assem bly in accordan ce w ith the disassem bly instructions in S ection 6.
5.2.14 Input Terminal Signal Tests The presen ce of signals o n either the digital or an alog input term inals ofthe drive can be verified on the drive disp lay.D igital oran alog inputstatus can be selected in the disp lay using the [D IS P LA Y M O D E ]key and the [+ ]and [-]keys on the keypad.
5.2.14.2 A na log inp uts The value ofsignals o n analog inp utterm inals 5 3,54,and 60 can also be d isplayed. The voltag e o n term inals 53 an d 54,orthe currentin m illiam ps for term inal60 is show n in line 2 ofthe disp lay.
5.2.14.1 D igitalinp uts W ith d igitalinputs disp layed,controlterm inals 16-33 are show n left to right,w ith a 1 indicating the presence ofa signal.
ANALOG I NPUT 60
12MA
DI GI TAL I NPUT
00101000 REMOTE
SETUP
1
SETUP
1
REMOTE
RUNNI NG
RUNNI NG
Ifthe desired signalis n ot present in the disp lay,the problem m ay b e either in the externalcontrolw iring to the drive or a faulty controlcard.To determ ine the fault location,use a volt m eter to test for voltage at the controlterm inals. Verify the controlvoltag e p ow ersupply is correctas follow s.
Ifthe desired signalis not presentin the disp lay,the problem m ay b e either in the externalcontrolw iring to the drive or a faulty controlcard.To determ ine the fault location,use a volt m eter to test for a signalat the controlterm inals. Verify the reference voltag e pow er supply is correct as follow s. 1. W ith a voltm eter m easure voltag e at co ntrol ca rd term inal50 w ith respect to term inal55. M eter should read betw een 9 .2 an d 11.2 V D C .
1. W ith a voltm eter m easure voltage at co ntrol card term inal12 and 13 w ith resp ectto term inal 20. M eter should read b etw een 21 a nd 2 7 V D C .
Ifthe 10 V supply vo ltag e is n otpresent,co nductthe C ontrol C ard Voltage Test earlier in this section.
Ifthe 2 4 V supply voltag e is notprese nt,co nd uctthe C ontrol C ard Test (5.2.15)earlier in this section.
Ifthe 10 volts is p resen tproceed w ith ch ecking the individual inputs as follow s.
If the 2 4 V is presen t proceed w ith checking the individual inputs as follow s. 2. C onnect (-)negative m eter lead to referen ce term inal20.
2. C onn ect (-)neg ative m eter lead to reference term inal55. 3. C onn ect(+ )positive m eter lead to desired term inal53,54 or 60.
3. C onnect (+ )positive m eter lead to term ina ls 16, 17, 18,19, 27, 29,32, and 33 in turn.
Fo ranalog inp ut term inals 53 and 54 ,a D C voltage b etw een 0 and +10 VD C should be read to m atch the analog signalbeing sent to the drive.
P resence ofa signalat the desired term inalshould co rrespond to the digitalinputdisplay read ing.A reading of24 VD C indicates the prese nce o f a signal. A reading of 0 VD C indicates n o signalis p resent.
Fo r an alog input term inal 60, a reading of 0.9 to 4.8 VD C correspon ds to a 4 to 20 m a sign al. N ote thata (-)m inus sign p reced ing any reading ab ove indicates a reversed polarity.In this case,reverse the w iring to the analog term inals.
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5.2.15 Control Card Test The co ntrolcard tests checks the operation ofthe analog and digitalinputs, the analog/digitalrelay o utputs and the + 10 V controlvoltag e.
16
17 18 19
04
05
61 68 69
20
27
28 32 33
13 38
42
45 50 53 54 55 60
1. C ycle p ow er to d rive. 2. A ccess param eter 620 , Operating Mod e ,an d select controlcard test. 3. R em ove pow er to d rive. 4. W ire co ntrolterm inals as show n in Figure 5-13.
12
5. R eap ply pow er to d rive. 6. P ress O K key on drive keypad . 7. C ontrolcard testw illbe carried outau tom atically. D isp lay w illindicate a pass o rfailm ode.Ifa failure is indicated,rep lace co ntrolcard in accordance w ith procedures in S ection 6. 8. Iftests p ass successfully,press O K key an d param eter 620 autom atically returns to norm al operation.
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Figure 5 -13. C ontrolC ard Te st C onn ec tions
5.3 INITIAL START UP OR AFTER REPAIR DRIVE TESTS Follow ing any repairto a d rive ortesting ofa d rive susp ected of being fau lty, the follow ing procedure m ust be follow ed to ensure thatallcircuitry in the drive is functioning properly b efore putting the u nitinto operation. 1. P erform visualinspection p rocedures as described in Table 3-1. 2. P erform static test procedures 5.1.1 to 5.1.3 to ensu re drive is safe to start. 3. D isco nn ectm otorleads from ou tput term inals (U , V, W )ofdrive. 4. A pp ly AC po w er to d rive. 5. G ive drive a run com m and and slow ly increase reference (speed com m and)to approxim ately 40 H z. 6. U sing an an alog volt m eter or a D V M cap ab le of m easuring true R M S ,m easure p hase-to-ph ase output voltag e o n allthree phases: U to V, U to W ,V to W .A llvoltag es m ust be b alanced w ithin 8 volts.Ifunbalan ced voltag e is m ea sured ,refer to Input Voltag e Test (5.2.1.1)in S ection 5. 7. S top drive and rem ove inp ut pow er.A llow 15 m inutes forD C ca pacitors to fully d ischarge. 8. R eco nnect m otor lead s to d rive ou tput term inals (U , V, W ). 9. R eapply po w er and restartdrive.A djust m otor speed to a n om inallevel. 10. U sing a clam p-on style am m eter,m easure output currenton each output phase. A ll cu rren ts should be b alan ced.Ifunb alanced cu rren tis m easured ,refer to C urrentS ensor Test (5.2.12)in S ection 5.
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SECTION 6 DISASSEMBLY AND ASSEMBLY INSTRUCTIONS
6.0 INSTRUCTIONS
! DANGER Drives contain dangerous voltages when connected to line voltage. No disassembly should be attempted with power applied. Remove power to drive and wait at least 15 minutes to let drive capacitors fully discharge. Only a competent technician should carry out service.
6.1 Control Card Cassette 1. R em ove co ntrolw iring b y unp lug ging con trol term inals (see Figure 6-1). 2. R em ove grounding clam ps by rem oving tw o screw s ho lding each in p lace. S ave screw s for reassem bly.
ELECTROSTATIC DISCHARGE (ESD) Many electronic components within the adjustable frequency drive are sensitive to static electricity. Voltages so low that they cannot be felt, seen or heard can reduce the life, affect performance, or completely destroy sensitive electronic components.
! CAUTION Use proper electrostatic discharge (ESD) procedures when servicing drive to prevent damage to sensitive components.
3. Fo rN EM A 12 configu ration s,disconnect cab le be tw een L C P and con trolcard. 4. U np lug the tw o ribbon cab les from side ofcontrol card. 5. Lo osen tw o cap tive screw s to free cassette (T2 0 Torx). 6. S lide cassette free from m ou nting tab s. 7. R em ove and rep lace co ntrolcard in acco rdance w ith instructions included w ith rep lacem en tcard. R einstallin reverse order of this p rocedure. E nsure that tw o ribbon cables are no tcrossed.Tighten co ntrolcard m ounting screw s to 8 in-lb (1 N m ).
Control card cassette Ribbon cable (Step 4)
LCP cable connector (Step 3) Control card
Control terminals (Step 1)
Captive screws (Step 5)
Grounding clamps (Step 2)
Figure 6 -1. C ontrolC ard C assette V LT is a registered D anfoss trad em ark
6-1
6.2 Interface Card 1. D isconnect cab les from connectors on interface card M K 100,M K 102 and M K 105.D isconnect cab les from con nectors M K 10 1 and M K 10 3 on ly if replacing interface card. 2. R em ove interface card b y rem ove 4 m oun ting screw s (T25 Torx)from standoffs. R einstall in reverse order of this p rocedure. Tighten T25 screw s an d interface card stan doffs to 20 in-lbs (2.25 N m ). C ard w illinitialize in service m ode.Follow instructions to enter data req uired .
5. R em ove current scaling card from po w er card by pushing in retaining clips on stan doffs.K E EP TH IS S C A L IN G C A R D T O R E IN S T A LL O N A N Y R EPLAC EM EN T PO W ER C AR D .Scaling card controls signals o perating w ith this specific VLT drive.S caling card is notpartofrep lacem en t po w ercard. R einstallin reverse orderofthis p rocedure.Tighten m ounting screw s and interface card stan doffs to 20 in-lbs (2.25 N m ).
6.4 Control Card/Power Card Mounting Plate 1. R em ove controlcard cassette and interface card in acco rdance w ith p roc ed ures.
6.3 Power Card 1. R em ove interface card in accordance w ith procedure.
2. R em ove 4 m ounting nuts (10m m ). 3. D isconnect allcab ling from pow er card.
2. D isconnect cables from conn ectors on po w er card M K 100,M K 102,M K 104,M K 105,M K 106, M K 107,M K 109,M K 110,FK100,and FK101.
4. R em ove o ption alw iring connection s,as necessary,to free m ounting plate.
3. R em ove 2 interface card stand offs (8m m ).
5. Liftplate free from chassis.
4. R em ove pow ercard by rem oving 5 m ounting screw s (T25 Torx)from standoffs.
R einstall in reverse order of this p roce dure. Torque T25 m oun ting screw s to 2 0 in-lbs (2.25 N m ).
Interface card PCA2 Interface card mounting screw
Current scaling card PCA4
Power card PCA3 Power card mounting screw
Interface card standoff
Mounting plate
Mounting plate standoff
Figure 6-2. Interfac e C ard , P ow er C ard , an d M oun ting P late 6-2
V LT is a reg istered D anfoss trad em ark
6.5 Gate Drive Card 1. D isconnect cab les from connectors on g ate drive card M K 10 2, M K 10 3, M K 10 4, and ,ifunithas extend ed brake o ption,M K 10 5. 2. R em ove gate d rivercard by rem oving 6 m ounting screw s (T25 Torx)from standoffs. R einstallin reverse orderofthis p rocedure.Tighten m ounting screw s to 20 in-lbs (2.25 N m ).
6.6 Soft Charge Card 1. R em ove con trolcard/po w ercard m ounting p late in accordance w ith p rocedure.
MK105 MK102 (U) brake option
MK103 (V)
MK104 (W)
Figure 6 -3.G ate D rive C ard 2. R em ove 2 retaining nuts from softcharge card assem bly (10m m ). Mounting screw (Step 2)
3. S lide assem bly partw ay ou tto access cab le connectors on card. 4. D isconnectM K1, M K 2,M K 3,and M K 4. 5. R em ove soft charge card assem bly.
MK2
R einstallby aligning so ft charge card w ith fastening clips o n the side ofthe ch assis.R ea ttach co nnectors.S lide into place and tighten m oun ting screw s to 35 in-lbs (4 N m ). MK4
MK1
MK3
Figure 6 -4. S oft C ha rge C ard A ssy
V LT is a registered D anfoss trad em ark
6-3
6.7 Capacitor Bank(s) NOTE Larger size units have 2 capacitor bank assemblies mounted one above the other. Separate disassembly instructions are given for upper and lower capacitor banks. For units with one capacitor bank assembly only, disassemble in accordance with instructions for single capacitor bank units.
Upper cover plate
Upper cover plate retaining nut
Upper cap bank assy retaining nuts
6.7.1 Upper Capacitor Bank 1. R em ove con trolcard cassette in acco rda nce w ith instructions. 2. C apacitor bank co nnection to D C bu s bars can be seen recessed in the g ap be tw een up per and low er cap banks.R em ove left m ost 2 n uts (10 m m )from D C bu s bars.A m inim um 4 in. exten sion is required. 3. R em ove 4 retaining nu ts (10 m m )from cap b ank co ver plate and rem ove cover plate. 4. N ote that w eigh tof cap bank is ap prox. 20 lbs. R em ove cap bank by pu lling free from m ou nting studs. R einstallin reverse orderofthis p rocedure.Tighten m ounting screw s to 35 in-lbs (4 N m ).
6.7.2 Lower Capacitor Bank 1. C apacitor bank co nnection to D C bu s bars can be seen recessed in the g ap be tw een up per and low er cap banks. R em ove right m ost 2 cap b ank retaining nu ts (10m m )from D C bus b ars.A m inim um 4 in.exten sion is req uired . 2. D isconnectM K102,M K103,M K104,and M K 106 from gate drive card.A lso rem ove M K 105 ,for un its w ith extended brake,and M K 101 forun its w ith R FIfilter. N ote that IG B T gate drive card can rem ain attached to cap bank cover plate. 3. R em ove 4 retaining nu ts (10 m m )from cap b ank co ver plate and rem ove plate. 4. N ote that w eigh tof cap bank is ap prox. 20 lbs. R em ove cap bank by pu lling free from m ou nting studs. R einstallin reverse orderofthis p rocedure.Tighten m ounting screw s to 35 in-lbs (4 N m ).
6-4
V LT is a reg istered D anfoss trad em ark
Lower cover plate retaining nut Gate drive card Lower cap bank assy retaining nuts
Figu re 6 -5. U p p er an d L ow er C ap acitor B an k A ssem b lies
6.7.3 Single Capacitor Bank Units 1. R em ove con trolcard cassette in acco rda nce w ith instructions.
Retaining nuts (Step 2)
2. R em ove 2 capictor ban k retaining nuts (10 m m ) from D C bus b ars.A m inim um 4 in. extension is required. 2. D isconnectM K102,M K103,M K104,and M K 106 from gate drive card.A lso rem ove M K 105 ,for un its w ith extended brake,and M K 101 forun its w ith R FIfilter. N ote that IG B T gate drive card can rem ain attached to cap bank cover plate. 3. R em ove 4 retaining nu ts (10 m m )from cap b ank co ver plate and rem ove plate. 4. N ote that w eigh tof cap bank is ap prox. 20 lbs. R em ove cap bank by pu lling free from m ou nting studs. R einstallin reverse orderofthis p rocedure.Tighten m ounting screw s to 35 in-lbs (4 N m ). Retaining nuts (Step 3)
Gate drive card (Step 3)
Figure 6 -6. S ing le C ap acitor B an k A ssem b ly
V LT is a registered D anfoss trad em ark
6-5
6.8 Soft Charge (SC) Resistors VL T 4000/ 4000/600 600 0/ 0/800 800 0 250 - 350 hp VLT 5000 200 - 300 hp 1. R em ove capacitor ban k assem assem bly in accordan accordan ce w ith p ro ce ced d ur ure. e.
NOTE On units with 2 capacitor banks mounted one above the other, only upper cap bank assembly is removed. 2. M K 4 connector connector on softcharge card card m ustbe d isco sc o n nect ne cted ed .D iseng se ng ag e so ftch char arg g e car c ard d fro m far en eno o ug h to acce ac cess ss M K 4 (see Fig ur ure e 6 -4 )in acco ac co rd an ce w ith step step s 1 1-3 in so ftch ar arg ge c car ard d d isassem b ly p roced oc edur ure. e. 3 . N o te tha that tsof so ftchar ch arg ge r res esi ist sto o r is lo ca cat ted un d er b us b ars ars an a n d h eld in p lac ace e b y 2 ret etai ain in g n ut uts. s.B us b ar ars s do no tnee need dt to o be r rem em oved .Lo ose osen nr ri igh t m o stret etai aining nu t(8 m m ). 4. R em ove left m ost 8m m retaining n ut. 5 . Liftlef eft tsid e o fS C res esi ist sto o r an d rem o ve resist sto o rb y slid in g to lef eft tan d o u tfro m u nd er bu s b ars. R ein st sta all in rev everse erse o rd er o f th is p ro ce ced d u re. T ig hten 8 m m m ou nt nti ing nu nut ts to 20 in-lb s (2. 2.25 25 N m ).Tigh ght ten 10 m m m ou nt nti ing n uts uts t to o 3 5 in -lb s (4 N m ).
Bus bars (do not remove)
Soft charge resistor Retaining nut (loosen) (Step 3)
Fig ure 6 6-7 . S o ft C ha rg e R esist sto or
66-6 6
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6.9 Soft Charge (SC) Resistors VL T 4000/ 4000/600 600 0/ 0/800 800 0 150 - 200 hp VLT 5000 125 - 150 hp 1. R em ove cap ca p acitor b an ank k per inst nstr ruc uct tion . 2. R em ove inp ut ter erm m inalm ou ount nti ing plate p er instructio ns. 3. R em ove ret retaining scr screw ew (T2 5)from ter erm m inal1 o f S C R /D iod e m od ule thr throu ough gh access ho le in b us ba bar r and rem ove bus b us bar ba r. C O N T IN U E D O N N E XT XT P A G E
Soft Charge Resistor
Bus bar (Step 3)
Retaining screw access (Step 3)
F ig u re 6 -8 . S o ft C h arge R esi es isto sto r (1 o f 3 )
V LT is a register ered ed D an anf fos oss s trad em ar ark k
66-7 7
4. R em ove six retaining screw screw s (T2 5)from S C R / D iod e m od ules,ter erm m ina nal ls 2 an and d 3 in e each ach m od ule. 5. R em ove four (10 m m )retaining nut nuts s from D C in d ucto rin p utb u s b ars a an n d fo urret etai aining n uts (no t show n)from side m oun ted b us bars. bars.R em ove D C inp ut b us assem b ly. C O N T IN U E D O N N E XT XT P A G E
Retaining nuts (Step 5)
Soft Charge Resistor
DC input bus assembly (Step 5)
Retaining screws (Step 4)
F ig u re 6 -8 . S o ft C h arge R esi es isto sto r (2 o f 3 )
66-8 8
V LT is a r reg eg ister ered ed D an anf fos oss st tr rad em ar ark k
6. R em ove softcharge resistor by rem oving tw o m ounting screw s.
R eassem bly 1. C lean heatsink surface w ith m ild solventoralco ho l so lution. 2. R eassem ble rem aining parts in reverse order of theirrem oval.Tigh ten T2 5 and 8m m m ou nting screw s to 2 0 in-lbs (2.25 N m )and T3 0 and 10 m m to 3 5 in-lbs (4 N m ).
Soft Charge Resistor
Mounting screws (Step 6)
Figure 6 -8. S oft C harge R esistor (3 of 3)
V LT is a registered D anfoss trad em ark
6-9
6.10 Input Terminal Mounting Plate Assy 1. R em ove up per m ostbu s bar retaining n uts (10 m m )from A C po w er inp ut bus bars R /L1,S / L2,and T/L3. 2. D isco nnect fan au totran sform er cable atin-line conn ector. 3. R em ove 6 (10m m )retaining n uts from m ounting plate.
! CAUTION Input terminal mounting plate weighs approx. 15 - 60 lbs, depending on mounted options. 4. R em ove entire assem bly from m ounting studs. R einstallin reverse orderofthis p rocedure.Tighten m ounting nuts to 35 in-lbs (4N m ).
Bus bar retaining nuts (shown removed) (Step 1)
Transformer connector (Step 2) Retaining nuts (Step 3)
Figure 6-9. Inp ut Term inalM oun ting P late A ssy 6-10
V LT is a reg istered D anfoss trad em ark
5. R em ove screw (T2 5) from term inal1 ofeach S C R /D iod e m od ule by accessing screw through access ho le in S C R /D iod e inp ut bus b ar.R em ove S C R inp ut bu s bars.
6.11 SCR/Diode Module VL T 4000/600 0/800 0 250 - 350 hp VLT 5000 200 - 300 hp 1. R em ove low er D C cap acitor bank p er instruction. 2. R em ove inp ut term inalplate p er instructions. 3. R em ove retaining nu ts (8m m )from S C R inpu tbu s bars.
6. R em ove each IG B T output bus bar by rem oving nut (10m m )from stud .A lso rem ove retaining screw (T30)at other end ofIG B T o utput bus b ars (no tsho w n). C O N TIN U E D N E XT P A G E
4. N ote the co lor coding for each ofthree w ires attached to retaining studs. Ensure that correct w ire is attached to ap plicable stud upon reassem bling .R em ove w iring from stud s.
SCR/Diode input bus bar retaining nut and stud (Steps 3 & 4)
SCR/Diode terminal screw (Step 5)
SCR/Diode input bus bar
IGBT output bus bar retaining nut (Step 6)
SCR/Diode terminal screw (Step 5)
IGBT output bus bar (Step 6)
Figu re 6 -10 . S C R /D iod e M od ule (1 of 4)
V LT is a registered D anfoss trad em ark
6-11
7. R em ove tw elve (T2 5)screw s from outpu t(low er) side ofIG B T m od ules. 8. R em ove retaining n ut (8m m )from each interm ed iate IG B T ou tput bus b ar.R em ove interm ed iate IG B T bus b ars. 9. R em ove 4 screw s (tw o on either side)con necting rectifier D C bus b ars to m ain D C bus b ars.These are located to eitherside ofS C R /D iode m odules. C O N T IN U E D N E XT P A G E
IGBT module
Main DC bus bar (Step 9)
Retaining nut (Step 8)
Retaining screws (Step 9) IGBT output retaining screws (Step 7)
Retaining screws (Step 9)
Intermediate IGBT output bus bar (Step 8)
Figu re 6 -10 . S C R /D iod e M od ule (2 of 4)
6-12
V LT is a reg istered D anfoss trad em ark
10 . R em ove rectifier D C bus bars by rem oving 3 screw s (T25)co nne cting each rectifier D C bus bar to stand offs on S C R /D iod e m od ules. C O N T IN U E D N E XT P A G E
Rectifier DC bus bars (Step 10)
Retaining screws (Step 10)
Figu re 6 -10 . S C R /D iod e M od ule (3 of 4)
V LT is a registered D anfoss trad em ark
6-13
Note Note which gate leads are attached to each module to ensure that leads are reconnected to correct modules upon reassembly.
REASSEMBLY 1. To rep lace S C R /D iode m od ules,follow instructions includ ed w ith rep lacem entm odule.
11. R em ove S C R gate lead conn ectors from m odules.
2. R eassem ble in reverse order.Tigh ten T 25 and 8m m m ounting screw s to 2 0 in-lbs (2.25 N m )and T30 to 35 in-lbs (4 N m ).
12. R em ove tw o S C R /D iod e m od ule retaining screw s on each m od ule (T30 )and rem ove S C R /D iod e m odules.
3. B e sure to cross tigh ten rep lacem ent unitper instructions w ith sp are part.
SCR/Diode module (Step 12) SCR gate lead connectors (Step 11)
SCR/Diode module mounting screws (Step 12)
Figu re 6 -10 . S C R /D iod e M od ule (4 of 4)
6-14
V LT is a reg istered D anfoss trad em ark
6.12 SCR/Diode Module Removal VL T 4000/600 0/800 0 150 - 200 hp VLT 5000 125 - 150 hp 1. R em ove capacitor bank per instruction . 2. R em ove inp ut term inalm ounting plate p er instructions. 3. R em ove retaining screw (T2 5)from term inal1 o f S C R /D iode m odule. 4. R em ove 8m m retaining n ut from bus b arholding bracket and rem ove b us b ar. C O N TIN U E D O N N E XT P A G E
Bus bar (Step 4)
Retaining screw access (Step 3)
Retaining nut (Step 4)
SCR/Diode module
Figu re 6 -11 . S C R /D iod e M od ule (1 of 3)
V LT is a registered D anfoss trad em ark
6-15
5. R em ove six retaining screw s (T2 5)from S C R / D iod e m od ules,term inals 2 and 3 in each m od ule. 6. R em ove four (10 m m )retaining nuts from D C inductorinputbus b ars and fourretaining nuts (not show n)from side m oun ted b us bars.R em ove D C inp ut bus assem bly. C O N TIN U E D O N N E XT P A G E
Retaining nuts (Step 6)
DC input bus assembly (Step 6)
Retaining screws (Step 5)
SCR/Diode module
Figu re 6 -11 . S C R /D iod e M od ule (2 of 3)
6-16
V LT is a reg istered D anfoss trad em ark
7. R em ove SC R /D iod e gate lead con nectors from m od ules (no tshow n). 8. Ifun itis eq uipped w ith b rake option ,rem ove tw o bus b ars attach ing brake IG B T m od ule to IG B T bu s assy.R em ove S C R /D iod e m ounting screw s.
R eassem bly 1. C lean he atsink surface w ith m ild solven t or alcoholso lution. 2. A sing le use p acke t of hea t transfer co m p ou nd is inc lud ed w ith each rep lacem en t S C R /D iod e m od ule a long w ith a tem p late for p rop er ap p lica tion.U se tem p late ap p ly h ea t tran sfer c om p o un d . 3. R einstallm od ule an d m ou nting screw s.Tigh ten T2 5 an d 8m m m ounting screw s to 20 in-lbs (2.25 N m )and T3 0 an d 1 0 m m to 3 5 in-lbs (4 N m ). B e su re to cross tighten rep lac em en t un it p er instructions w ith sp are p art. 4. R eassem b le rem aining pa rts in reverse o rd er of their rem oval.
SCR/Diode module
Mounting screws (Step 8)
Figu re 6 -11 . S C R /D iod e M od ule (3 of 3)
V LT is a registered D anfoss trad em ark
6-17
6.13 Current Sensor 1. R em ove m otor cab ling,as required. 2. R em ove inp utterm inalm ounting plate assem bly perinstructions. 3. R em ove term inals U , V, and W by rem oving 3 m oun ting screw s.Term inalslides ou tfrom un der cu rren tsensor. 4. D isconnect currentsenso rcab le from current sensor. 5. R em ove 2 (8m m )retaining n uts from stud on chassis b asep late and rem ove senso r. R einstall in reverse o rder of this p rocedure. Tighten 8m m m oun ting nuts to 20 in-lbs (2.25 N m ).
Current sensor
Terminal mounting screw
Terminal
Current sensor mounting screws (2)
Terminal mounting screws (2)
Output motor cable connection screws (2)
Figure 6 -12.C urren t S en so rs
6-18
V LT is a reg istered D anfoss trad em ark
3. U se 4 in.m inim um extension an d rem ove term inal 1 ofS C R /D iod e m od ule.
6.14 Fan Assembly 1. R em ove inp utterm inalm ounting plate assem bly perinstructions. 2. R em ove 3 IG B T output bus bars by rem oving 6 retaining nu ts (8m m ),one from each end,of IG B T outpu tbus bars.R em ove b us bars.
NOTE Omit steps 3 and 4 for 200 hp units.
4. N ote the co lor co ding for each ofthree w ires attached to retaining studs. Ensure that correc t w ire is attached to ap plicab le stud upon reassem bling .R em ove A C po w er lead to interm ed iate S C R inp ut bus b ar by rem oving nut (8m m )and rem ove bus bar. C O N T IN U E D O N N E X T P A G E
Intermediate SCR input bus bar (Step 3) Terminal (Step 3) Retaining nut (Step 4)
Retaining nut (Step 2)
IGBT output bus bar (Step 2)
Retaining nut (Step 2)
Figure 6-13 . F an A ssem b ly (1 o f 2) V LT is a registered D anfoss trad em ark
6-19
5. D isconnect in-line m olex connector. 6. R em ove fan assy by rem oving 6 (8m m )retaining nu ts from stud .N ote thatfan assy w eigh s ap prox. 18 lbs. R einstallin reverse orderofthis p rocedure.Tighten m ounting nuts to 20 in-lbs (2.25 N m ).
Inline molex connector (Step 6)
Retaining nut (Step 7)
Figure 6-13 . F an A ssem b ly (2 o f 2)
6-20
V LT is a reg istered D anfoss trad em ark
6.15 AC Input Terminals 1. R em ove A C inpu tpo w ercabling, as required. 2. R em ove R /L1,S /L2 ,T/L3 term inals by rem oving 3 retaining screw s. R einstallin reverse orderofthis p rocedure.Tighten m ounting nuts persp ecifications in the unit's instruction m anual.
Retaining screw (Step 2) AC input terminal Retaining screws (Step 2)
AC input cable connector (Step 1)
Figure 6 -14. A C Inp ut Term inals
V LT is a registered D anfoss trad em ark
6-21
6.16 IGBT Modules VLT 4000/6000/8000 250 - 350 hp VLT 5000 200 - 300 hp 1. R em ove capacitory ban ks perinstruction s. 2. N ote IG B T gate signalcables conn ected betw een gate drive card con nectors M K 10 2 (U ),M K 10 3 (V),and M K 104 (W )and IG B Ts.These w illneed to be reconn ected in sam e locations during reassem bly.U nits w ith brake option w illhave brake cabling from M K 105 in addition. D isco nnect cab les at con nectors on IG B T m od ules. 3. R em ove retaining nu ts (8m m )from S C R inp utbu s bars.
4. N ote the co lor co ding for each ofthree w ires attached to retaining studs. Ensure that correc t w ire is attached to ap plicab le stud upon reassem bling .R em ove w iring from stud s. 5. R em ove screw (T2 5) from term inal1 ofeach S C R /D iod e m od ule by accessing screw through access ho le in S C R /D iod e inp ut bus b ar.R em ove S C R inp ut bu s bars. 6. R em ove each IG B T output bus bar by rem oving nut (10m m )from stud .A lso rem ove retaining screw (T30)at other end ofIG B T o utput bus b ars (no tsho w n). C O N T IN U E D O N N E X T P A G E
Snubber capacitor
IGBT gate signal input terminal (Step 2)
SCR/Diode input bus bar retaining nut and stud (Steps 3 & 4)
SCR/Diode terminal screw (Step 5) IGBT output bus bar retaining nut (Step 6)
SCR/Diode terminal screw (Step 5)
SCR/Diode input bus bar
IGBT output bus bar (Step 6)
Figure 6-15 . IG B T M od ules (1 o f 3)
6-22
V LT is a reg istered D anfoss trad em ark
7. R em ove 4 (10 m m )retaining n uts attop of IG B T bus b ar assy. 8. R em ove 12 retaining screw s (6 on each m od ule) on up per portion of IG B T m od ules.Th ese screw s also attach the snu bber capacitors to the IG B T m od ules (see F igu re 6 -14 3 of 3).R em ove the snub ber capacitors (notshow n).
11. A tbo ttom end o fIG B T m od ule,rem ove 12 retaining screw s (4 each for U , V, an d W interm ed iate IG B T o utputbus b ars). 12. R em ove retaining nut(8m m )from 3 interm ed iate IG B T o utput bus bars.R em ove interm ed iate IG B T output bus b ars. C O N T IN U E D O N N E X T P A G E
9. R em ove 10m m retaining nut from IG B T bus bar assy. 10. R em ove IG B T bus bar assy. IGBT bus bar assembly (Steps 7 & 10)
Retaining nut (Step 9)
Retaining nut (Step 7)
Retaining screws (shown removed) (Step 8) IGBT module
Retaining screws (Step 11)
IGBT module
Retaining nut (Step 12)
Intermediate IGBT output bus bar (Step 12)
Figure 6-15 . IG B T M od ules (2 o f 3)
V LT is a registered D anfoss trad em ark
6-23
13. R em ove 2 IG B T m odules by rem oving 16 retaining screw s (8 p er m odule)and slide m odules free from under bus b ars. 14. C lean heatsink surface w ith m ild solventor alco hol so lution.
R E A S S E M B LY 1. R eplace IG B T m od ule in accordan ce w ith instructions provided w ith replacem entunit. 2. R eassem ble rem aining parts in reverse order of theirrem oval. 3. R einstallm od ule and m ou nting screw s.Tigh ten T2 5 and 8m m m ounting screw s to 2 0 in-lbs (2.25 N m )and T 30 an d 1 0 m m to 35 in-lbs (4 N m ).B e sure to cross tighten rep lacem en tunitper instructions w ith sp are part.
IGBT module
Retaining screw (Step 13)
Figure 6-15 . IG B T M od ules (3 o f 3)
6-24
V LT is a reg istered D anfoss trad em ark
6.17 IGBT Modules VLT 4000/6000/8000 150 - 200 hp VLT 5000 125 - 150 hp 1. R em ove controlcard cassette per instruction s. 2. R em ove inp ut term inalm ounting plate p er instructions. 3. N ote IG B T gate signalcables conn ected betw een gate drive card con nectors M K 10 2 (U ),M K 10 3 (V ),and M K 10 4 (W )and IG B T m od ule co nn ectors.These w illneed to b e reconnected in sam e locations d uring reassem bly.U nits w ith brake option w illhave b rake cabling from M K 105 in ad dition. R em ove cap acitory bank p er instructions. 4. D isconnect gate d rive cab les at connectors on IG B T m odules. 5. D isconnect cable connected to conn ector M K 10 0 on high freq uency card. Retaining screw (Step 6)
6. R em ove high frequen cy card b y rem oving 2 retaining screw s and 1 retaining nut. 6A . Fo run its w ith b rake option, D C inp ut bus assem bly m ustbe rem oved to access and rem ove bus bars betw een IG B T b us bar assem bly (see F igu re 6 -15 2 of 2) and brake IG B T.R em ove D C inp ut bus b ar assem bly per step s 3 - 5 o f S C R /D iod e M od ule R em oval(S m allerM od els). 6B .Fo run its w ith b rake option, rem ove b us b ars betw een IG B T b us bar assem bly (see Figu re 6-15 2 o f2) and brake IG B T b y rem oving tw o T 25 retaining screw s on b rake IG B T (no t sho w n) and tw o 8 m m retaining nuts on IG B T b us b ar assem bly (notshow n). 7. R em ove 3 IG B T output bus bars by rem oving nut (10m m )from stud .A lso rem ove retaining screw (T30)at other end ofIG B T ou tput bus bars (no t show n). C O N T IN U E D O N N E X T P A G E High frequency card Connector MK100 (Step 5)
DC input bus bar assembly (Step 6A)
Retaining nut (Step 6) Do not remove (Step 6)
Gate drive cable connectors (Steps 3 & 4)
IGBT module IGBT output bus bar (Step 7)
IGBT output bus bar retaining nut (Step 7)
Figure 6-16 . IG B T M od ule (1 o f 2) V LT is a registered D anfoss trad em ark
6-25
8. R em ove 4 (10 m m )retaining n uts attop of IG B T bus b ar assy. 9. R em ove 6 retaining screw s on up per po rtion of IG B T m od ules. Th ese screw s also a ttach the snubber cap acitors to the IG B T m od ules. R em ove 3 snub bercap acitors. 10. R em ove IG B T bus bar assy. 11. A t bo ttom end ofIG B T m od ule,rem ove 6 retaining screw s (2 each for U , V, an d W interm ed iate IG B T o utput bus bars).
R E A S S E M B LY 1. R eplace IG B T m od ule in accordan ce w ith instrucions enclosed w ith rep lacem entm odule. 2. Tighten m ounting screw s in accordance w ith the tightening patterns.Tighten T25 and 8m m m ou nting screw s to 20 in-lbs (2.25 N m )and T3 0 and 10 m m to 3 5 in-lbs (4 N m ). 3. R eassem ble drive in reverse o rder ofdisassem bly and tighten attaching hardw are in acco rdance w ith torque tab les.
12 . R em ove retaining nut(8m m )from 3 interm ed iate IG B T o utput bus b ars.R em ove interm ed iate IG B T ou tput bus b ars. 13.R em ove IG B T m odule. 14.C lean heatsink su rface w ith m ild solventor alcohaolso lution.
IGBT bus bar assembly (Step 8) Retaining nut (Step 8)
Snubber capacitor (Step 9)
IGBT module
Retaining screw (Step 9)
Retaining nut (Step 11)
Intermediate IGBT output bus bar (Step 11)
Figure 6-16 . IG B T M od ule (2 o f 2) 6-26
V LT is a reg istered D anfoss trad em ark
SECTION 7 SPECIAL TEST EQUIPMENT
TEST EQUIPMENT V arious test tools have been developed by D anfoss to aid in troub lesh ooting these products.Itis h ighly recom m ended for rep air and servicing of this equipm en t that these tools b e availab le to the technician.W ithoutthem som e troubleshooting procedures described in this m anua lcann ot be carried out. E ven tho ug h som e test points co uld possibly be foun d inside the drive to probe for sim ilar signals, these tools p rovide a safe and sure point form aking the necessary m easurem ents. Test equipm ent described in this section is available from D anfoss.
Test Cable and SCR Shorting Plug (p/n 176F8439) SCR shorting plug
3.R einstall so ft ch arge c ard, rep lace p ow er ca rd m ounting plate,and reinstallcontrolcard. 4. U np lug cable at po w er card c onn ector M K 10 5. Insert other end of test ca ble into pow er card connector M K 105 . 5. U np lug cable at po w er card c onn ector M K 10 0. P lug S C R sho rting plug into p ow er card connector M K 1 00. W hen reapplying m ain inp ut pow er to the drive the softcharge rectifier w illsupply D C pow erto the p ow er ca rd to en ab le the pow er sup plies. Testing involving the u se of the g ate signal board and the signaltestboard can now be carried out w itho ut the p resence ofthe D C bus.
Signal Test Board (p/n 176F8437)
Cable with connectors
Figu re 7 -1. Te st C ab le an d S C R S ho rting P lug
This tool provides the ability to power up the Switch Mode Power Supplies (SMPS) and activate all the control functions of the drive without having the DC bus charged. This is not only an extremely useful tool but there is no safer way to troubleshoot gate drive signals and other important control signals within the drive than having the DC bus disabled. The cable is connected between the soft charge card and the power card. The SCR shorting plug shorts the gates of the SCRs to ensure they do not fire and add a charge to the DC bus. To install the cable first ensure the drive is powered down and the DC bus is fully discharged. The soft charge card must be extracted to the point to gain access to the necessary connections. This will require the removal of the control card and the power card mounting plate. Follow the instructions in Section 6 for disassembly of these items. 1. R em ove po w er to d rive. 2.S lide softcharge card outjustfar eno ugh to un plug cab le at co nn ector M K 3 o n so ft charge card. C onnect on e end o ftest cab le into M K 3.
Figure 7-2. S ignal Test B oard The S ignalTest B oard provides access to a variety o fsigna ls thatcan be helpfulin troubleshooting the drive. The signaltestboard is p lugged into interface card co nnector M K 104 . P oints on the sign al test boa rd can be m on itored w ith orw itho ut the D C bus disab led .In som e cases the drive w illneed the D C bus en ab led an d operating a load to verify som e testsignals. Follow ing is a description ofthe signals available on the signal test board. S ection 5 of this m anua ldescribes w he n the se tests w ould be c alled for and w ha t the signalshould be at thatgiven test point.
V LT is a reg istered D anfoss trad em ark
7-1
Signal Test Board Pin Outs: Description and Voltage Levels The tables on the follow ing pag es list the p ins located on the signaltest board.For each pin,its function,description,and voltage levels are p rovided.D etails on perform ing tests using the test fixture are p rovided in S ection 5 ofthis m anual.O ther than pow er sup ply m easu rem ents,m ost of the sign als b eing m easured are m ade up of w aveform s. A ltho ug h in som e cases a d igital voltm eter can be u sed to verify the presen ce ofsuch signals, it can not be relied upon to verify that the w aveform is correct.A n oscilloscope is the instrum en tprefered.H ow ever,w hen sim ilar signals are b eing m easured at m ultiple p oints, a d igitalvoltm eter can be u sed w ith som e d eg ree ofconfidence.B y co m paring severalsignals to each other,such as gate d rive signals,and obtaining sim ilar read ing s,itcan be co nclud ed eac h o fthe w aveform s m atch one an othe r an d are therefore correct. Values are p rovided for using a digitalvo ltm eter for testing as w ell.
7-2
V LT is a registered D anfoss trad em ark
Pin No. 1
Schematic Acro nym IU1
Function
2
IV1
Current sensed, V phase, not conditioned
3
IW1
Current sensed, W phase, not conditioned
4 5
COMMON AMBT
Logic common Ambient temp.
6
FANO
7
INRUSH
8
RL1
9
EXT24V
10
TEMP_HS
11
VPOS
12
VNEG
Control Card signal Control Card signal Control Card signal Signal to Control Card Analog signal inversely proportional to HS temp +18 VDC supply. +12 VDC to +15 VDC –18 VDC supply –12 VDC to – 15 VDC
Description
Reading Using a Digital Volt Meter .937 VACpeak @ 165% of CT current rating. AC waveform @ output frequency of the drive.
Current sensed, U phase, not conditioned
App rox 400 mv R MS @ 100 % lo ad .937 VACpeak @ 165% of CT current rating. AC waveform @ output frequency of the drive.
App rox 400 mv R MS @ 100 % lo ad .937 VACpeak @ 165% of CT current rating. AC waveform @ output frequency of the drive.
App rox 400 mv R MS @ 100 % lo ad This common is for all signals. Used to control FAN high and low fan speeds. Signal from Control Card to turn fans on and off. Signal from Control Card to start gating SCR front end Signal from Control Card to provide status of Relay 01 Signal indicating a backup power supply is active. Will read ~ 3.3 volts if the heat sink NTC is disconnected. As HS temperature goes up the voltage goes down.
Red LED indicates voltage is present between VPOS and VNEG terminals. Red LED indicates voltage is present between VPOS and VNEG terminals.
1VDC approximately equal to 25C 0VDC – ON command 5VDC – OFF command 5VDC – SCRs disabled 0VDC – SCRs enabled 5VDC – Relay active 0VDC – inactive 5VDC – backup present 0VDC – no backup Formula, VDC = 2.82 – 0.035 * (T – 30), where T is the temperature in degrees Celsius. +18 VDC regulated supply +16.5 to 19.5 VDC -18 VDC regulated supply -16.5 to 19.5 VDC
V LT is a reg istered D anfoss trad em ark
7-3
Pin No. 13
Schematic Acro nym DBGATE
Function
Description
14
BRT_ON
Brake IGBT 5V logic level signal.
15
OTFLT
16
FAN_TST
17
FAN_ON
Temperature / Voltage out of range Control signal for fans Pulse train to gate SCR’s for fan voltage control. In sync with line freq.
18
HI_LOW
19
SCR_DIS
20
INV_DIS
Control signal from Power Card
Disables IGBT gate voltages
21
RFI_RL2
Ground signal to enable RFI HF capacitors
22
UINVEX
23
VDD
Control signal for RFI Bus Voltage scaled down +24 VDC power supply
24
VCC
+5.0 VDC regulated supply. +4.75-5.25 VDC
Green LED indicates voltage is present.
Brake IGBT gate pulse train
Reading Using a Digital Volt Meter Voltage drops to zero when brake is turned off. Voltage increases to 4.04 VDC as brake duty cycle reaches max.
Varies w/ brake duty cycle
7-4
Control signal from Power Card Control signal for SCR front end
5.10 VDC level with the brake turned off. Voltage decreases to zero as brake duty cycle reaches max.
Varies w/ brake duty cycle Monitors Brake resistor, Heatsink temp, Ambient temp, power supplies voltages. Indicates Fan Test switch is activated to force the fans on high
7 trigger pulses at 3Khz Signal to switch fan speeds between high and low Indicates SCR front end is enabled or disabled.
Signal proportional to UDC Yellow LED indicates voltage is present.
V LT is a registered D anfoss trad em ark
5VDC – No fault 0VDC – Fault +5VDC – disabled 0VDC – fans on high 5VDC - fans off ~4.3VDC – fans on
+5VDC = fans on high, Otherwise 0VDC. 0.6 to 0.8 VDC – SCRs enabled 0VDC – SCR disabled 5VDC – inverter disabled 0VDC – inverter enabled 24VDC – no RFI 0VDC – RFI enabled 1VDC = 262 VDC OV switch must be off. +24 VDC regulated supply +23 to 25 VDC +5.0 VDC regulated supply +4.75 to 5.25 VDC
Pin No. 25
Schematic Acro nym GUP_T
Function
26
GUN_T
IGBT gate signal, buffered, U phase, negative. Signal originates on Control Card.
27
GVP_T
IGBT gate signal, buffered, V phase, positive. Signal originates on Control Card.
28
GVN_T
IGBT gate signal, buffered, V phase, negative. Signal originates on Control Card.
Description
IGBT gate signal, buffered, U phase, positive. Signal originates on Control Card.
Reading Using a Digital Volt Meter 2.2 - 2.5 VDC Equal on all phases TP25-TP30
2v/div 100us/div Run@10Hz 2.2 - 2.5 VDC Equal on all phases TP25-TP30
2v/div 100us/div Run@10Hz 2.2 - 2.5 VDC Equal on all phases TP25-TP30
2v/div 100us/div Run@10Hz 2.2 - 2.5 VDC Equal on all phases TP25-TP30
2v/div 100us/div Run@10Hz
V LT is a reg istered D anfoss trad em ark
7-5
Pin No. 29
Schematic Acro nym GWP_T
Function
30
GWN_T
IGBT gate signal, buffered, W phase, negative. Signal originates on Control Card.
Description
IGBT gate signal, buffered, W phase, positive. Signal originates on Control Card.
Reading Using a Digital Volt Meter 2.2 - 2.5 VDC Equal on all phases TP25-TP30
2v/div 100us/div Run@10Hz 2.2 - 2.5 VDC Equal on all phases TP25-TP30
2v/div 100us/div Run@10Hz
7-6
V LT is a registered D anfoss trad em ark
VLT is a reg istered Danfoss trademark
8-5
8-5
VLT is a reg istered Danfoss trademark
8-6 9-2
VLT is a reg istered Danfoss trademark
9-1
8-6 9-2
VLT is a reg istered Danfoss trademark
9-1
