Ansi Codes

ANSI Codes – Device Designation Numbers

In the design of electrical power systems, the ANSI Standard Device Numbers (ANSI /IEEE Standard !"#$% denote what features a protective device supports (such as a relay or circuit brea&er%# brea& er%# 'hese types of devices protect electrical systems and components from damage when an unwanted event occurs, such as an electrical fault# Device numbers are used to identify the functions of devices shown on a schematic diagram# unction unction descriptions are given in the standard# ANSI/IEEE !"#$)$**+ is one of a continuing series of revisions of the standard, which originated in -$+#

Device Numbers

# .AS'E E0E.EN'

is the initiating device, such as a control switch, voltage relay, 1oat switch, etc#, which serves either directly or through such permissive devices as protective and time)delay relays to place an e2uipment in or out of operation#

$ # ' I . E D E 0 A 3 S 'A 'A  ' I N 4 5   0 5 S I N 4  E 0 A3

is a device that functions to give a desired amount of time delay before or after any point of operation in switching se2uence or protective relay system, e6cept as speci7cally provided by service function 8+, 9$, and "-#

!# :E;IN4 5 IN'E05;IN4 E0A3

is a relay that operates in response to the position of a number of other devices (or to a number of predetermined conditions% in an e2uipment, to allow an operating se2uence to proceed, or to stop, or to provide a chec& of the position of these devices or of these conditions for any purpose#

8# .AS'E 5N'A'5

is a device generally controlled by device function or the e2uivalent and the re2uir re2uired ed permissive and protective devices, that serves to ma&e and brea& the necessary control circuits to place an e2uipment into operation under the desired conditions and to ta&e it out of operation under other or abnormal conditions#

$ # ' I . E D E 0 A 3 S 'A 'A  ' I N 4 5   0 5 S I N 4  E 0 A3

is a device that functions to give a desired amount of time delay before or after any point of operation in switching se2uence or protective relay system, e6cept as speci7cally provided by service function 8+, 9$, and "-#

!# :E;IN4 5 IN'E05;IN4 E0A3

is a relay that operates in response to the position of a number of other devices (or to a number of predetermined conditions% in an e2uipment, to allow an operating se2uence to proceed, or to stop, or to provide a chec& of the position of these devices or of these conditions for any purpose#

8# .AS'E 5N'A'5

is a device generally controlled by device function or the e2uivalent and the re2uir re2uired ed permissive and protective devices, that serves to ma&e and brea& the necessary control circuits to place an e2uipment into operation under the desired conditions and to ta&e it out of operation under other or abnormal conditions#

<# S'5==IN4 DE>IE

is a control device used primarily to shut down an e2uipment and hold it out of operation# ('his device may be manually or electrically actuated, but e6cludes the function of electrical loc&out ?see device function +9@ on abnormal conditions#%

Top 9# S'A'IN4 II' BEA;E

is a device whose principal function is to connect a machine to its source of starting voltage#

"# AN5DE II' BEA;E

is a device used in the anode circuits of a power recti7er for the primary purpose of interrupting the recti7er circuit if an arc)bac& should occur#

+# 5N'50 =5CE DIS5NNE'IN4 DE>IE

is a disconnecting device, such as a &nife switch, circuit brea&er, or pull)out fuse bloc&, used for the purpose of respectively connecting and disconnecting the source of control power to and from the control bus or e2uipment#

Note: control power is considered to include au6iliary power which supplies such apparatus as small motors and heaters# -# E>ESIN4 DE>IE

is a device that is used for the purpose of reversing a machine 7eld or for performing any other reversing functions#

*# NI' SEENE SCI':

is a switch that is used to change the se2uence in which units may be placed in and out of service in multiple)unit e2uipments#

Top # ESE>ED 5 'E A==0IA'I5N

(SB assigned  ontrol =ower 'ransformer%#

$# 5>E)S=EED DE>IE

is usually a direct)connected speed switch which functions on machine over)speed#

!# S3N:5N5S)S=EED DE>IE

is a device such as a centrifugal switch, a slip)fre2uency relay, a voltage relay, and undercurrent relay , or any type of device that operates at appro6imately the synchronous speed of a machine#

8# NDE)S=EED DE>IE

is a device that functions when the speed of a machine fall below a pre )determined value#

<# S=EED 5 EEN3 .A':IN4 DE>IE

is a device that functions to match and hold the speed or fre2uency of a machine or of a system e2ual to, or appro6imately e2ual to, that of another machine, source, or system#

Top 9# ESE>ED 5 'E A==0IA'I5N

(SB assigned  Battery harging Device%#

"# S:N'IN4 5 DIS:A4E SCI':

is a switch that serves to open or to close a shunting circuit around any piece of apparatus (e6cept a resistor, such as a machine 7eld, a machine armature, a capacitor, or a reactor%#

Note:  'his e6cludes devices that perform such shunting operations as may be necessary in the process of starting a machine by devices 9 or 8$, or their e2uivalent, and also e6cludes device function "! that serves for the switching of resistors# +# AE0EA'IN4 5 DEE0EA'IN4 DE>IE

is a device that is used to close or to cause the closing of circuits which are used to increase or decrease the speed of a machine#

-# S'A'IN4)'5)NNIN4 'ANSI'I5N 5N'A'5

is a device that operates to initiate or cause the automatic transfer of a machine from the starting to the running power connection#

$ * # > A 0> E

is one used in a vacuum, air, gas, oil, or similar line, when it is electrically operated or has electrical accessories such as au6iliary switches#

Top $# DIS'ANE E0A3

is a relay that functions when the circuit admittance, impedance, or reactance increases or decreases beyond predetermined limits#

$$# EA0IFE II' BEA;E

is a brea&er that serves to control or to ma&e and brea& the e2ualiGer or the current)balancing connections for a machine 7eld, or for regulating e2uipment in a multiple )unit installation#

$ ! # ' E . = E  A'   E  5 N '  5 0 D E > I  E

is a device that function to raise or lower the temperature of a machine or other apparatus, or of any medium, when its temperature falls below, or rises above, a predetermined value#

Note: An e6ample is a thermostat that switches on a space heater in a switchgear assembly when the temperature falls to a desired value as distinguished from a device that is used to provide automatic temperature regulation between close limits and would b e designated as device function -*'# $8# ESE>ED 5 'E A==0IA'I5N

(SB assigned  bus tie circuit brea&er, contactor, or switch#%

$<# S3N:5NIFIN4 5 S3N:5NIS.):E; DE>IE

is a device that operates when two a)c circuits are within the desired limits of fre2uency, phase angle, or voltage, to permit or to cause the paralleling of these two circuits

Top $ 9 # A = = A  A'  S ' : E  . A 0 D E > I  E

is a device that functions when the temperature of the shunt 7eld or the amortisseur winding of a machine, or that of a load limiting or load shifting resistor or of a li2uid or other medium, e6ceeds a predetermined valueH or if the temperature of the protected apparatus, such as a power recti7er, or of any medium decrease below a predetermined value#

$"# NDE>50'A4E E0A3

is a relay that functions on a given value of under)voltage#

$+# 0A.E DE'E'5

is a device that monitors the presence of the pilot or main 1ame of such apparatus as a gas turbine or a steam boiler#

$-# IS50A'IN4 5N'A'5

is a device that is used e6pressly for disconnecting one circuit from another for the purposes of emergency operation, maintenance, or test#

!*# ANNNIA'5 E0A3

is a non)automatically reset device that gives a number of separate visual indications of the functions of protective devices, and which may also be arranged to perform a loc&out function#

Top !  # S E = A A' E E   I 'A' I 5 N D E > I  E

is a device that connects a circuit, such as the shunt 7eld of a synchronous converter, to a source of separate e6citation during the starting se2uenceJ or one that energiGes the e6citation and ignition circuits of a power recti7er#

!$# DIE'I5NA0 =5CE E 0A3

is a device that functions on a desired value of power 1ow in a given direction or upon reverse power resulting from arcbac& in the anode or cathode circuits of a power recti7er#

!!# =5SI'I5N SCI':

is a switch that ma&es or brea&s contact when the main device or piece of apparatus which has no device function number reaches a given position#

!8# .AS'E SEENE DE>IE

is a device such as a motor)operated multi)contact switch, or the e2uivalent, or programming device, such as a computer, that establishes or determines the operating se2uence of the maKor devices in a e2uipment during starting and stopping or during other se2uential switch operations#

!<# BS:)5=EA'IN4 5 S0I==IN4 S:5')II'IN4 DE>IE

is a device for raising, lowering, or shifting the brushes of a machine, or for short)circuiting its slip rings, or for engaging or disengaging the contacts of a mechanical recti7er#

Top !9# =50AI'3 5 =50AIFIN4 >50'A4E DE>IE

is a device that operates, or permits the operation of, another device on a predetermined polarity only, or veri7es the presence of a polariGing voltage in an e2uipment#

! " #  N D E      E N ' 5   N D E  = 5 C E   E 0 A3

is a relay that function when the current or power 1ow decreases below a predetermined value#

!+# BEAIN4 =5'E'I>E DE>IE

is a device that functions on e6cessive bearing temperature, or on another abnormal mechanical conditions associated with the bearing, such as undue wear, which may eventually result in e6cessive bearing temperature#

!-# .E:ANIA0 5NDI'I5N .5NI'5

is a device that functions upon the occurrence of an abnormal mechanical condition (e6cept that associated with bearing as covered under device function !+%, such as e6cessive vibration, eccentricity, e6pansion shoc&, tilting, or seal failure#

8 * #  I E 0 D  E 0 A3

is a relay that functions on a given or abnormally low value or failure of  a machine 7eld current, or on e6cessive value of the reactive component of armature current in an a)c machine indicating abnormally low 7eld e6citation#

Top 8# IE0D II' BEA;E

is a device that functions to apply or remove the 7eld e6citation of a machine#

8$# NNIN4 II' BEA;E

is a device whose principal function is to connect a machine to its source of running or operation voltage# 'his function may also be used for a device, such as a contactor, that is used in series with a circuit brea&er or other 7eld protecting means, primarily for fre2uent opening and closing of the brea&er#

8!# .ANA0 'ANSE 5 SE0E'5 DE>IE

is a manually operated device that transfers the control circuits in order to modify the plan of operation of the switching e2uipment or of some of the devices#

88# NI' SEENE S'A'IN4 E0A3

is a relay that function to start the ne6t available unit in a multiple) unite2uipment upon the failure or non)availability of the normally preceding unit#

8 < # A ' . 5S = : E  I   5 N D I ' I 5 N . 5 N I ' 5 

is a device, that functions upon the occurrence of an abnormal atmospheric condition, such as damaging fumes, e6plosive mi6tures, smo&e or 7re#

Top 89# E>ESE =:ASE 5 =:ASE BA0ANE EN' E0A3

is a relay that functions when the polyphase currents are of reverse) phase se2uence, or when the polyphase currents are unbalanced or contain negative phase)se2uence components above a given amount#

8 " # = : A S E ) S E   E N  E > 5 0' A4 E  E 0 A3

is a relay that function upon a predetermined value of polyphase voltage in the desired phase se2uence#

8 + # I N  5 . = 0 E ' E S E   E N  E  E 0 A3

is a relay that generally returns the e2uipment to the normal, or oL , position and loc&s it out if the normal starting, operating, or stopping se2uence is not properly completed within a predetermined time# If the device is used for alarm purposes only, it should preferably be designated as 8+A (alarm%#

8-# .A:INE 5 'ANS5.E ':E.A0 E0A3

is a relay that functions when the temperature of a machine armature or other load)carrying winding or element of a machine or the temperature of a power recti7er or power transformer (including a power recti7er transformer% e6ceeds a predetermined value# <*# INS'AN'ANE5S 5>EEN' 5 A'E )5)ISE E0A3

is a relay that functions instantaneously on an e6cessive value of current or on an e6cessive rate of current rise, thus indicating a fault in the apparatus or circuit being protected#

Top <# A) 'I.E 5>EEN' E0A3

is a relay with either a de7nite or inverse time characteristic that functions when the current in an a)c circuit e6ceed a predetermined value#

<$# A) II' BEA;E

is a device that is used to close and interrupt an a)c power circuit under normal conditions or to interrupt this circuit under fault of emergency conditions#

< ! # E   I ' E  5  D )  4 E N E  A' 5   E 0 A3

is a relay that forces the d)c machine 7eld e6citation to build up during starting or which functions when the machine voltage has been built up to a given value#

<8# :I4:)S=EED D) II' BEA;E

is a circuit brea&er which starts to reduce the current in the main circuit in *#* second or less, after the occurrence of the d)c overcurrent or the e6cessive rate of current rise#

< < # = 5 C E  A  ' 5   E 0 A3

is a relay that operates when the power factor in an a)c circuit rises above or falls below a predetermined value#

Top <9# IE0D A==0IA'I5N E0A3

is a relay that automatically controls the application of the 7eld e6citation to an a)c motor at some predetermined point in the slip cycle#

<"# S:5')II'IN4 5 45NDIN4 DE>IE

is a primary circuit switching device that functions to short)circuit or to ground a circuit in response to automatic or manual means#

< + #  E  ' I  I  A ' I 5 N A I 0   E  E 0 A3

is a device that functions if one or mote anodes o f a power recti7er fail to 7re, or to detect and arc)bac& or on failure of a diode to conduct o r loc& properly#

< - # 5 > E  > 5 0' A 4 E  E 0 A 3

is a relay that functions on a given value of over)voltage#

9 * # > 5 0' A4 E 5      E N ' B A 0 A N  E  E 0 A3

is a relay that operates on a given diLerence in voltage, or current input or output, or two circuits#

Top 9# ESE>ED 5 'E A==0IA'I5N#

9 $ # ' I . E ) D E 0 A 3 S ' 5 = = I N 4 5  5 = E N I N 4  E 0 A3

is a time)delay relay that serves in conKunction with the device that initiates the shutdown, stopping, or opening operation in an a utomatic se2uence or protective relay system#

9 ! # 0 I   I D 5  4 A S =  E S S   E 5  >A    .  E 0 A 3

is a relay that operates on given values of li2uid or gas pressure or on given rates of change of these values#

9 8 # 4  5  N D =  5 ' E  ' I > E  E 0 A3

is a relay that functions on failure of the insulation of a machine, transformer, or of other apparatus to ground, or on 1ashover of a d)c machine to ground#

Note:  'his function is assigned only to a relay that detects the 1ow of current from the frame of a machine or enclosing case or structure of piece of apparatus to ground, or detects a ground on a n ormally ungrounded winding or circuit# It is not applied to a device connected in the secondary circuit of current transformer, in the secondary neutral of current transformers, connected in the power circuit of a normally grounded system#

9<# 45>EN5

is the assembly of 1uid, electrical, or mechanical control e2uipment used for regulating the 1ow of water, steam, or other medium to the prime mover for such purposes a starting, holding speed or load, or stopping#

Top 99# N5':IN4 5 M544IN4 DE>IE

is a device that functions to allow only a speci7ed n umber of operations of a given device or e2uipment, or a speci7ed number of successive operations within a given time of each other# It is also a device that functions to energiGe a circuit periodically or for fractions of speci7ed time intervals, or that is used to permit intermittent acceleration or Kogging of a machine at low speeds for mechanical positioning#

9"# A) D IE'I5NA0 5>EEN' E0A3

is a relay that functions on a desired value of a)c over)current 1owing in a predetermined direction#

9+# B05;IN4 E0A3

is a relay that initiates a pilot signal for bloc&ing of tripping on e6ternal faults in a transmission line or in other apparatus under predetermined condition, or cooperates with other devices to bloc& tripping or to bloc& re)closing on an out)of)step condition or on power savings#

9-# =E.ISSI>E 5N'50 DE>IE

is generally a two)position, manually)operated switch that, in one position, permits the closing of a circuit brea&er, or the placing of an e2uipment into operation, an in the other position prevents the circuit brea&er or the e2uipment from being operated#

" * #  : E 5 S ' A'

is a variable resistance device used in an electric circuit, which is electrically operated or has other electrical accessories, such a au6iliary , position, or limit switches#

Top "  # 0 I   I D 5  4 A S ) 0 E > E 0  E 0 A3

is a relay that operates on given values of li2uid or gas level or on given rates of change of these values#

"$# D) II' BEA;E

is a circuit brea&er that is used to close and interrupt a d)c power circuit under normal conditions or to interrupt this circuit under fault or emergency conditions#

"!# 05AD)ESIS'5 5N'A'5

is a contactor that is used to shunt or insert a step of load limiting, shifting, or indicating resistance in a power circuit, or to switch a space heater in circuit, or to switch a light or regenerative load resistor, a power recti7er, or other machine in and out of circuit#

" 8 # A 0 A  .  E 0 A3

is a relay other than an annunciator, as covered under device function !*, that is used to operate, or to operate in connection with, a visual or audible alarm#

"<# =5SI'I5N :AN4IN4 .E:ANIS.

is a mechanism that is used for moving a main device from one position to another in an e2uipmentH as for e6ample, shifting a removable circuit brea&er unit to and from the connected, disconnected, and test positions#

Top "9# D) 5>EEN' E0A3

is a relay that function when the current in a d)c circuit e6ceeds a given value#

" " # =  0 S E '  A N S . I '' E 

is used to generate and transmit pulses over a telemetering or pilot) wire circuit to the remote indicating or receiving device#

" + # = : A S E ) A N 4 0 E . E A S   I N 4 5  5  ') 5  ) S ' E = =  5 ' E  ' I > E  E 0 A3

is a relay that functions at a pre)determined phase angle between two voltages or between two currents or between a voltage and current#

"-# A) E05SIN4 E0A3

is a relay that controls the automatic reclosing and loc&ing out of an a) c circuit interrupter#

+*# 0IID 5 4AS 05C E0A3

is a relay that operates on given values of li2uid or gas 1 ow or on given rates of change of these values#

Top +# EEN3 E0A3

is a relay that functions on a predetermined value of fre2uency (either under or over or on normal system fre2uency% or rate of change of fre2uency#

+$# D) E05SIN4 E0A3

is a relay thast controls the automatic closing and re)closing of a d)c circuit interrupter, generally in response to load circuit conditions#

+ ! # A  ' 5 . A 'I  S E 0 E  ' I > E  5 N '  5 0 5  '  A N S  E   E 0 A3

is a relay that operates to select automatically between certain sources or conditions in a e2uipment, or performs a transfer operation automatically#

+8# 5=EA'IN4 .E:ANIS.

is the complete electrical mechanism or servomechanism, including the operating motor, solenoids, position switches, etc#, for a tap changer, induction regulator, or any similar piece of apparatus which otherwise has no device function number#

+<# AIE 5 =I05')CIE EEI>E E0A3

is a relay that is operated or restrained by a signal used in connection with carrier)current or d)c pilot)wire fault directional relaying#

Top

+ 9 # 0 5  ; I N 4 ) 5  '  E 0 A3

is an electrically operated hand, or electrically reset relay or device that functions to shut down or hold an e2uipment out of service, or both, upon the occurrence of abnormal conditions#

+"# DIEEN'IA0 =5'E'I>E E0A3

is a protective relay that functions on a percentage or phase angle or other 2uantitative diLerence of two currents or of some other electrical 2uantities#

++# AI0IA3 .5'5 5 .5'5 4ENEA'5

is one used for operating au6iliary e2uipment, such as pumps, blowers, e6citers, rotating magnetic ampli7ers, etc#

+-# 0INE SCI':

is a switch used as a disconnecting, load)interrupter, or isolating switch in an a)c or d)c power circuit, when this device is electrically operated

or has electrical accessories, such as an au6iliary switch, magnetic loc&, etc#

-*# E40A'IN4 DE>IE

is a device that functions to regulate a 2uantity, or 2uantities, such as voltage, current power, speed, fre2uency, temperature, and load at a certain value or between certain (generally close% limits for machines, tie lines, or other apparatus#

Top -  # > 5 0' A4 E D I  E  ' I 5 N A 0  E 0 A3

is a device which operates when the voltage across an open circuit brea&er or contactor e6ceeds a given value in a given direction#

- $ # > 5 0' A4 E A N D = 5 C E  D I  E  ' I 5 N A 0  E 0 A 3

is a relay that permits or causes the connection of two circuits when the voltage diLerence between them e6ceed a given value in a predetermined direction and causes these two circuits to be

disconnected from each other when the power 1o wing between them e6ceeds a given value in the opposite direction#

- ! #  I E 0 D )  : A N 4 I N 4  5 N 'A  ' 5 

is a contactor that functions to increase or decrease, in one step, the value of 7eld e6citation on a machine#

- 8 # '  I = = I N 4 5  '  I = )   E E  E 0 A3

is a relay that function to trip a circuit brea&er, contactor or e2uipment, or to permit immediate tripping by other devicesJ or to prevent immediate re )closure of a circuit interrupter if it should open automatically even though its closing circuit is maintained closed#

- < #  (  S B  A S S I 4 N E D   0 5 S I N 4  E 0 A 3 5   5 N ' A ' 5  %

Top -9#

-"#

-+# (SB ASSI4NED  05SS 5 EI'A'I5N E0A3%

- - #  (  S B  A S S I 4 N E D  A  D E ' E  ' 5  %

 sed only for speci7c applications in individual installations where none of the assigned numbered functions from  to -8 are suitable#

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Au6iliary Devices

 'hese letters denote separate au6iliary devices, such asH

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C  losing elay or ontactor

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CL  Au6iliary elay, losed (energiGed when main device is in closed position%#

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CS  ontrol Switch

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D  ODownP =osition Switch or elay

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L  0owering elay

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1.  5pening elay

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OP  Au6iliary elay, 5pen (energiGed when main device is in open position%#

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P  =ush Button

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!  aising elay