2750M Drive Unit User Guide Issue 2 Part Number 31-3275DUSA
Freq 118.250 MHz
Handbook Title:
2750M Drive Unit User Guide
Handbook Part Number:
31-3275DUSA
Issue Number:
2
Date of Issue:
March 2001
Published By:
Park Air Electronics Northfields Market Deeping Peterborough England England PE6 8UE 8UE
Telephone:
From UK, 01778 345434 From outside outside UK, 44 1778 345434 345434
Fax:
From UK, 01778 342877 From outside outside UK, 44 1778 342877 342877
www.parkair.co.uk
Page 2
2750M Drive Unit
Amendment Record Amendments Amendments to this user guide, initiated by PAE, are recorded in the following table. Amendment Number
Incorporated by:
Date
Brief Details
Modification Record Modifications to the 2750M drive unit, authorized by PAE, are recorded in the following table. Modification Embodied by: Number 1
2750M Drive Unit
PAE
Date
Brief Details
April 00
Retaining Retaining clip removed removed from ac mains mains connecto connector. r. Change note 3818 refers.
Page 3
Fault Report To ensure that PAE continues to offer the highest level of after sales service, it is necessary to gather as much information as possible about equipment faults. In the event of an equipment fault, or failure, please complete a copy of this report and return it to the Customer Services Department at PAE.
Customer Address
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . EQUIPMENT DETAILS PAE works order number (Cxxxxx or Mxxxxx) Equipment model
. . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Equipment serial number
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
SERVICE DETAILS Commissioning date
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Failure/repair date . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Supply voltage ac/dc
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
*Transmitter keying: Continuous / approx 50% / occasional use *Equipment environment: Office area / dedicated equipment room / heated / air-conditioned [*Delete as applicable] FAULT DETAILS Symptoms of fault Results of any tests
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Any repairs carried out
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Comments/action requested
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Name
. . . . . . . . . . . . . . . . . . . . . . . .
Department
. . . . . . . . . . . . . . . . . . . . .
Telephone . . . . . . . . . . . . . . . . . . . . . . Fax
. . . . . . . . . . . . . . . . . . . . . . . . .
Email . . . . . . . . . . . . . . . . . . . . . . . . .
Page 4
2750M Drive Unit
Contents Introduction
7
General Information
7
Front Panel Display
7
Operating Modes
8
Local Operation
8
Remote Operation
8
Use Within a MARC System
8
Built-In Test (BIT) Indications
9
Part Number and Model Identification
9
Part Number
9
Model Identification
9
Specification
11
General Characteristics
11
RF and Modulation Characteristics
11
Interfaces
12
Dimensions and Weight
12
Operating Instructions
13
Introduction
13
Front Panel Controls, Indicators and Connectors
13
AC Power Switch
13
DC Power Switch
13
Control Panel
14
Alarm Indicator
15
Freq Socket
15
Rear Panel
16
AC Input Connector (CN5)
16
DC Input Connector (CN4)
16
Fuse F1
16
RF Drive (CN2)
16
Facilities Connector (CN3)
16
Facilities Connector (CN7)
16
Chassis Stud
16
L.O. Drive
16
2750M Drive Unit
Page 5
Operation
17
Power Up
17
Local Operation
17
Remote Operation
17
Changing the Operating Frequency
18
Frequency Display Readout
18
Using the BIT Information Page
19
To Initiate a BIT Interruptive Test
19
To Set the Drive Unit’s Frequency Standard:
20
Setting the Operating Frequency when using Offset Carrier Systems
21
Installation
23
Preliminary Checks
23
Mechanical Installation
23
Telescopic Slides
23
Fixed Runners
23
External Connections
24
AC Voltage Selection
24
Supply Fuses
26
AC Input Connection
26
DC Input Connection
27
Connecting the Chassis Stud to Earth
27
RF Drive Connection
28
Facilities Connector CN3
28
Facilities Connector CN7
29
Page 6
2750M Drive Unit
Introduction
GENERAL INFORMATION The Park Air Electronics (PAE) type 2750M drive unit is a fully synthesised multi-frequency unit designed to provide the carrier frequency for a 2750SA transmitter. By setting the front panel controls, the unit can provide any 25 kHz spaced channel frequency from 118.000 to 136.975 MHz. Additionally, the drive unit supports 2, 3, 4, or 5-offset carrier systems. The unit fits into a standard 483 mm (19 inch) equipment rack on either fixed runners or telescopic slides. It is powered from a standard ac input supply, or from a low voltage dc supply. When both ac and dc input supplies are connected, operation from the ac supply takes priority; automatic change-over to the dc supply occurs if the ac supply fails. On restoration of the ac supply, the equipment reverts to ac operation.
FRONT PANEL DISPLAY A Liquid Crystal Display (LCD) is fitted to the drive unit’s front panel. By using the display and associated control switches, four information/control pages can be selected:
Page 4. Allows the user to adjust the drive unit’s frequency standard. Page 3. Allows the drive frequency to be changed.
Page 2. Accesses the Built-In Test facilities.
Page 1. Shows the current drive frequency.
Freq 118.250 MHz
2750M Drive Unit
Page 7
OPERATING MODES The drive units can be operated in local or remote mode, or as part of a PAE MARC system. The various operating modes are described in the following paragraphs.
Local Operation In local operation the drive frequency can be changed using the front panel Liquid Crystal Display (LCD) and control keys. Additionally, BIT status can be seen and an interruptive BIT test can be initiated.
Remote Operation For remote operation, input and output signals are available from the drive unit’s rear panel Facilities connector CN3. These signals can be routed to the user’s control equipment through a suitable communication link. The signals include:
A 600 ohm balanced audio input
Tape output
Tx signal
Normal/wideband select signal
Wideband audio input
External PTT
BIT alarms (2750SA transmitter and drive unit alarms)
Various Built-in Test (BIT) indications (included as part of the serial data)
Remote frequency change signals (included as part of the serial data).
Use Within a MARC System The PAE Multi-Access Remote Control (MARC) system provides monitoring and control of a multi-station radio system. A typical MARC system comprises a number of remote radio sites that are operated from an Air Traffic Control (ATC) centre. At the ATC, a Personal Computer (PC) acts as the MARC user interface. All MARC functions are monitored and controlled from graphical screens displayed on the PC. When used in a MARC system the drive unit’s BIT information and other facilities are interfaced with the MARC Remote Site Equipment (RSE). In addition, the associated 2750SA transmitter’s BIT information, audio, and other facilities are interfaced with the MARC RSE via the drive unit. When the drive unit and transmitter are configured in this way, the operating frequency can be changed and an interruptive BIT test can be initiated from a graphical representation of the transmitter and drive unit displayed on the MARC’s PC. Additionally, the system monitors the continuous BIT information so that specific transmitter and drive unit faults are displayed at the PC. Further details of the facilities provided by MARC are shown in the MARC User Guide.
Page 8
2750M Drive Unit
BUILT-IN TEST (BIT) INDICATIONS The drive unit has two levels of Built-In Tests (BIT): Continuous monitoring and an interruptive test. Some critical test points are continuously monitored during operation. These are, synthesiser lock, RF drive and transmitter power supply status. If a synthesiser lock or RF drive fault is detected, the front panel Alarm indicator lights. Faulty parameters can be identified using the front panel keys to scroll the BIT results. If a transmitter power supply failure is detected the Alarm indicator flashes on the drive unit. When an interruptive test is initiated the TX indicator on the 2750SA transmitter lights. If a failure is detected the transmitter Alarm lamp illuminates and the failed parameter can be determined from the front panel, or remotely via the MARC PC screen (if used). Transmitter parameters monitored via the transmitter front panel meter include forward power, VSWR and unregulated voltage. If a fault is detected, the drive unit Alarm lamp lights.
PART NUMBER AND MODEL IDENTIFICATION Part Number The PAE part number for the drive unit is: B2750DU
Model Identification Each drive unit has a model identification label fitted to one of the chassis side panels. An example label is illustrated below.
PAE PARK AIR ELECTRONICS
PAE model number
Model 2750DU Drive Unit Serial No 1234 Option: Volts
Setting of the mains input voltage link (when dispatched from PAE) The drive unit’s serial number
2750M Drive Unit
240
Watts 75
The drive unit’s ac power consumption Identifies any options fitted to the drive unit
Page 9
Intentionally Blank
Page 10
2750M Drive Unit
Specification
GENERAL CHARACTERISTICS The general characteristics of the 2750M drive unit are: Frequency range
118.000 to 136.975 MHz
Channel spacing
25 kHz
Frequency temperature stability
better than 0.3 ppm (-20 to +55°C)
Frequency ageing
better than 0.75 ppm per year
Frequency step size
2.5 kHz
Frequency change time
<100 ms
Power supplies: ac
99 to 132 V or 198 to 264 V, 45 to 65 Hz <75 VA
dc
19 to 32 V <1.5 A
Current overload
Current overload protected by fuses mounted on the rear panel (ac and dc)
Temperature range (operating)
-20 to +55°C
Temperature range (non-operating)
-30 to +70°C
Duty cycle
100% continuous operation.
RF AND MODULATION CHARACTERISTICS The RF characteristics of the 2750M drive unit are: RF drive level
20 dBm 2 dB at RF drive connector
Frequency monitor
Fundamental 6 MHz, between 50 and 150 mV pk-pk
2750M Drive Unit
Page 11
INTERFACES Interface specifications of the 2750M drive unit are: RF drive
N-type female connector, 50 ohm, marked ‘CN2 RF Drive’
AC supply
3-pin IEC male, marked ‘AC INPUT CN5’
DC supply
3-pin XLR male, marked ‘CN4 DC INPUT’
Frequency monitor
BNC female front panel connector. Suitable to drive high impedance counter. Marked ‘FREQ’
Facilities
Marked ‘CN3 FACILITIES’, D-type 25-way socket mounted on rear panel Marked ‘CN7 FACILITIES’, D-type 25-way plug mounted on rear panel.
DIMENSIONS AND WEIGHT The dimensions and weight of the 2750M drive unit are: Width
483 mm (19 inches)
Height
88 mm (3.46 inches)
Depth
334 mm (13.2 inches)
Weight
6 kg (13.2 pounds).
Page 12
2750M Drive Unit
Operating Instructions
INTRODUCTION This section describes the function of the drive unit’s external controls, indicators and connectors, and provides operating instructions. No attempt should be made to operate the drive unit until the installation instructions have been completed.
FRONT PANEL CONTROLS, INDICATORS AND CONNECTORS
Freq 118.250 MHz
Front Panel Layout
(GA9971)
AC Power Switch Two-position switch with associated amber indicator. Setting the switch to the on position (up) connects ac input power to the drive unit’s circuitry. When switched on, the amber indicator above the switch is lit.
DC Power Switch Two-position switch with associated amber indicator. Setting the switch to the on position (up) connects dc input power to the drive unit’s circuitry. When switched on, the amber indicator above the switch is lit.
(SA2354)
Note... When both ac and dc supplies are available and connected, the drive unit operates on ac power only; both supply indicators, however, are lit. If the ac supply fails, the drive unit automatically switches to operate from the dc supply. Under these circumstances, only the dc indicator is lit showing that the drive unit is operating on the dc supply. Reversion to ac operation is automatic when the ac supply is restored and is shown by both indicators being lit.
2750M Drive Unit
Page 13
Control Panel The control panel contains a Liquid Crystal Display (LCD) and four keys. The LCD can display one of four information pages as listed below: PAGE key.
Selects the required page.
CURSOR key.
Selects fields within the selected page.
key.
Makes changes to the selected field.
key.
Makes changes to the selected field.
Freq 118.250 MHz
Control Panel’s Default Page (Page 1)
If no control panel keys are pressed for 30 seconds, the LCD defaults to Page 1: the unit’s current drive frequency.
Page 1
Page 2
Shows the drive unit’s current drive frequency. This is the default page and is displayed if no other pages are selected for 30 seconds.
An interruptive BIT test can be initiated from Page 2. Additionally, the page allows the user to view the status of the continuous BIT signals listed below. Detailed instructions regarding the use of this page are given on page 19.
Synthesiser (Synth Lock)
Synthesiser (RF Drive).
F re q
1 18 .2 50 M Hz
BIT Test Synth Lock OK
Page 3
Allows the drive unit’s operating frequency to be changed. Detailed instructions regarding the use of this function are given on page 18.
Freq 118.250 MHz OK CANCEL
Page 4
Allows adjustment of the drive unit’s frequency standard. This adjustment forms part of the drive unit’s annual maintenance and is detailed on page 20.
! Freq Standard ! ADJ OK CANCE L
Page 14
2750M Drive Unit
Alarm Indicator The Alarm indicator is normally unlit. It lights to show a fault has been detected within the drive unit. When the Alarm indicator is lit, users should select Page 2 on the control panel to display more information about the fault. Note ... If the Alarm indicator is flashing this indicates a power supply failure in the associated 2750SA transmitter.
Freq Socket BNC socket that allows monitoring of the drive unit’s frequency standard (6.000 MHz). The frequency standard is displayed (and can be reset) on the LCD when Page 4 is selected. The instructions for resetting the standard are given on page 20.
2750M Drive Unit
(SA2356)
Page 15
REAR PANEL
Rear Panel Layout (GA9972)
AC Input Connector (CN5) 3-pole plug, with integral fuse, for connection of the ac input supply. The value of the integral fuse depends on the local ac input supply (see page 26).
DC Input Connector (CN4) A 3-pin plug for the drive unit’s optional 28 V (nominal) dc input supply. Note that only two of the three pins are used. Connector details are described on page 27.
Fuse F1 A 3.15 amp anti-surge fuse (PAE part number 29-01470102) that protects the dc input circuit.
RF Drive (CN2) N-type socket used to connect the drive unit’s RF output to the transmitter.
Facilities Connector (CN3) A 25-way D-type socket for external facilities connections. The facilities connections are detailed in the Installation section.
Facilities Connector (CN7) A 25-way D-type plug for external facilities connections to the associated 2750SA transmitter. The facilities connections are detailed in the Installation section.
Chassis Stud A chassis stud is fitted on the drive unit’s rear panel. This stud must be connected to the equipment rack (if the drive unit is rack mounted) or the user’s system grounding point to ensure compliance with EMC regulations. Connection, and further details are given on page 27.
L.O. Drive Connector CN6 is not fitted.
Page 16
2750M Drive Unit
OPERATION Power Up Carry out a visual inspection ensuring that the required connectors are securely fitted. At the front panel, set the AC and/or the DC Power switches to on (up). Confirm that the associated indicators are lit. Confirm that the Alarm indicator is unlit and that the LCD shows the drive unit’s current drive frequency.
Local Operation The following operations are available from the drive unit’s front panel:
Changing the operating frequency. If the drive frequency requires changing, refer to the procedure given on page 18.
Using the BIT information page. If during operation of the transmitter and drive unit the Alarm indicator becomes lit, the equipment should normally be switched off and the fault reported to the appropriate engineering personnel. If the Alarm indicator is unlit, and a fault is suspected, a BIT interruptive test can be initiated. The procedure for initiating an interruptive test is given on page 19.
Alarm Flashing If during operation of the transmitter and drive unit the Alarm indicator starts flashing, one of the following conditions is indicated:
2750SA transmitter PSU failure
The facilities lead between the 2750SA transmitter and the drive unit is disconnected
The 2750SA transmitter is switched off.
If the 2750SA transmitter is switched on and the facilities lead is connected, the transmitter should be operated locally and any fault conditions revealed at the transmitter’s front panel meter recorded. Following this the fault should be reported to the appropriate engineering personnel along with any recorded information.
Remote Operation Remote operation of the drive unit and associated 2750SA transmitter means control and monitoring at a position remote from where the transmitter and drive unit are installed. To achieve this, modulation input (and any other required facilities) routed via the drive unit’s rear panel Facilities connector, must be connected through a suitable link to the control position. The method of operation, therefore, depends on how the equipment facilities are configured and cannot be detailed in this publication. If the drive unit is being used as part of a Multi-Access Remote Control (MARC) system, users should refer to the MARC User Guide.
2750M Drive Unit
Page 17
Changing the Operating Frequency The drive unit’s operating frequency is changed by using the PAGE, CURSOR, and keys. To change the frequency, proceed as follows: (1)
Press the Page key until Page 3 is displayed.
(2)
Press the Cursor key until the cursor is under the last digit of the MHz display (as shown in the illustration).
(3)
Press, and keep pressed, either the key (to increase frequency) or the key (to decrease frequency). The MHz value increments, or decrements, in steps of 1 MHz. Release the key when the required value is displayed.
(4)
Press the Cursor key until the cursor is under the last digit of the kHz display.
(5)
Press, and keep pressed, either the key (to increase frequency) or the key (to decrease frequency). The kHz value increments, or decrements, in steps of 2.5 kHz. Release the key when the required value is displayed. Although the frequency increments and decrements in steps of 2.5 kHz, the frequency is shown in MHz only to three decimal points (see next heading for additional detail).
(6)
If the frequency change needs cancelling, press the Cursor key until the cursor is under the CANCEL symbol. Then press the key. The display reverts to the original setting.
(7)
When the required frequency is displayed, press the Cursor key until the cursor is under the OK symbol. Then press the key. The drive unit is now tuned to the new frequency. Check that the display defaults to Page 1 and displays the new frequency.
Freq 118.250 MHz OK CANCEL
Page 3 Display
Frequency Display Readout The front panel display shows the frequency in MHz to three decimal points, for example, 118.500 MHz. When setting the frequency using the procedure given above, the frequency increments and decrements in 2.5 kHz steps. The exact frequency cannot therefore be displayed. The following chart illustrates the frequency readout. The difference in displayed frequency and actual frequency is important only when setting offset frequency channels. Example frequency incrementing by 2.5 kHz
Displayed Frequency
Actual Frequency
Start frequency = 118.500
118.500
118.500
Increment by 2.5 kHz
118.502
118.5025
Increment by 2.5 kHz
118.505
118.505
Increment by 2.5 kHz
118.507
118.5075
Increment by 2.5 kHz
118.510
118.510
and so on ...
Page 18
2750M Drive Unit
Using the BIT Information Page The drive unit’s continuous BIT information is displayed, and an interruptive BIT test can be initiated, by using the Page, Cursor, and keys. To view continuous BIT indications: (1)
Press the Page key until Page 2 is displayed.
(2)
Press the Cursor key until the cursor is under the symbol (as shown in the illustration).
(3)
Press the key, or the key, to toggle the two continuous BIT indications. These are: Synth Lock and RF Drive.
(4)
If no fault has been detected, the screen shows OK . If a fault is detected the screen shows Fail .
BIT Test Synth Lock OK
Page 2 Display
To Initiate a BIT Interruptive Test An interruptive BIT test temporarily halts the drive unit’s normal operation and causes the associated 2750SA transmitter to radiate a modulated carrier for approximately half a second. (1)
Press the Page key until Page 2 is displayed.
(2)
Press the Cursor key until the cursor is under the symbol (as shown in the illustration).
(3)
Press the key to initiate the test. Check the front panel Alarm indicator remains unlit.
(4)
If at the end of the interruptive test, which lasts for approximately half a second, the Alarm indicator is lit, check both continuous BIT indications to establish the nature of the fault.
2750M Drive Unit
BIT Test Synth Lock OK
Page 2 Display
Page 19
To Set the Drive Unit’s Frequency Standard: To set the drive unit’s frequency standard, use the following procedure. Note however, that if the drive unit has been set to use a 3 or 5-offset carrier frequency, this procedure should not be used (refer to ‘Setting the Operating Frequency when using Offset Carrier Systems’ on page 21). (1)
Connect a frequency counter to the drive unit’s front panel FREQ connector.
(2)
Press the PAGE key until Page 4 is displayed.
(3)
Press the CURSOR key until the cursor is under the symbol (as shown in the illustration).
(4)
Press the and keys to adjust the frequency until the frequency counter’s display reads exactly 6.000 MHz.
(5)
When the frequency counter reads exactly 6.000 MHz, press the CURSOR key until the cursor is under the OK symbol.
(6)
! Freq Standard ! ADJ OK CANCEL
Page 4 Display
Press the key. The drive unit’s frequency standard is now reset. Notes ... After adjusting the frequency standard, and before entering OK, the adjustment can be cancelled by pressing the CURSOR key until the cursor is under the CANCEL symbol. Then press the key. The display reverts to the original setting. To achieve the required accuracy, a high stability (better than 0.5 ppm) frequency counter must be used to set the drive unit’s frequency standard.
Page 20
2750M Drive Unit
Setting the Operating Frequency when using Offset Carrier Systems The 2750SA transmitter/2750M drive unit can operate with a 2, 3, 4, or 5-offset carrier system. The offsets that can be used in accordance with the requirements of the International Civil Aviation Organisation (ICAO) Annex 10 are: 2-carrier system:
carriers are spaced at 5 kHz
3-carrier system:
carriers are spaced at zero, and 7.3 kHz
4-carrier system:
carriers are spaced at 2.5 kHz, and 7.5 kHz
5-carrier system:
carriers are spaced at zero,
4
kHz, and 8 kHz
The procedure on page 18 sets the operating frequency; any frequency from 118 to 136.975 MHz in steps of 2.5 kHz can be selected. This allows any 25 kHz channel to be selected, and also the offset frequencies when using a 2 or 4-offset carrier system. It does not allow 3 or 5-offset carrier system frequencies to be set. To set the drive unit when using a 3 or 5-offset carrier system, proceed as follows: (1)
Connect a suitable VHF counter to the associated 2750SA transmitter’s front panel FREQ connector. Note ... The frequency can be read with or without the transmitter being keyed; no attenuator is required.
(2)
Refer to ‘Changing the Operating Frequency’ on page 18 and set the drive unit to the nearest 2.5 kHz frequency. For example, if the required frequency is 124.504 MHz, set the transmitter to 124.505 MHz.
(3)
Press the Page key until Page 4 is displayed.
(4)
Press the Cursor key until the cursor is under the symbol.
(5)
Press the and keys to adjust the frequency until the frequency counter displays the required operating frequency. For example, 124.504 MHz.
(6)
When the frequency counter displays the exact operating frequency, press the Cursor key until the cursor is under the OK symbol.
(7)
Press the key.
(8)
Disconnect the frequency counter.
When operating with a 3 or 5-offset carrier system, the drive unit’s frequency standard (see page 20) must not be set to 6.000 MHz. As a confidence check to ensure the drive unit’s frequency output is accurate, the procedure given on this page should be completed during routine maintenance.
2750M Drive Unit
Page 21
Intentionally Blank
Page 22
2750M Drive Unit
Installation
WARNING! Installation involves the connection of lethal voltages. The instructions detailed in this section must be carried out only by suitably qualified personnel.
PRELIMINARY CHECKS Carefully remove the transit packaging and carry out a visual inspection of the unit. If any damage has occurred, contact PAE for advice.
MECHANICAL INSTALLATION Caution! It is essential that the chosen mechanical installation provides adequate support along the depth (front to rear) of the unit. The drive unit must not be supported by the front panel; doing so can cause damage. The equipment can be installed on telescopic slides, or on fixed runners, within a standard 483 mm (19 inch) equipment rack. Four M4 tapped holes, each 10 mm deep, are provided on each side of the equipment for fitting slides or runners. Details of suitable telescopic slides and fixed runners are available from PAE.
Telescopic Slides Dependent on the rack/slide combination used, it may be necessary to fit a spacer bar between the runner and the equipment. The width of the spacer must be such that the runners locate correctly within the slide assemblies. Installation must be in accordance with instructions relating to the rack, or cabinet, in use. The drive unit is secured to the rack through the front panel fixing holes using suitable hardware.
Fixed Runners The fixed runners, if used, must provide adequate support along the depth (front to rear) at both sides of the unit. The unit is secured to the rack through the four front panel fixing holes using suitable hardware.
2750M Drive Unit
Page 23
EXTERNAL CONNECTIONS The following external connections are required to the equipment:
ac input supply (see note)
dc input supply (see note)
Facilities CN7 connections (to the 2750SA transmitter)
Facilities CN3 connections (for remote control)
RF drive (to the 2750SA transmitter)
Chassis stud connection to equipment rack, or system earth. Note ... The equipment operates from either an ac, or dc, supply. When both ac and dc are connected, operation from the ac supply takes priority; automatic change-over to the dc supply occurs if the ac supply fails. On restoration of the ac supply, the equipment reverts to ac operation. The ac supply input link must be correctly set before a mains supply is connected.
AC VOLTAGE SELECTION Caution! Before operating the equipment for the first time, the ac input selector link must be set to correspond with the local ac supply. The equipment can operate with an ac input supply between 99 and 132 V, or between 198 and 264 V. The drive unit’s input selector link must be set (either to 115 V or 240 V) to suit the local ac supply. The link, LK1, is fitted to the Power Supply module’s PCB. Access is as follows: (1)
Ensure the ac and dc supplies are isolated from the drive unit.
(2)
Unscrew the nine panel fasteners that secure the drive unit’s top cover. Remove the cover.
(3)
Using the illustration on page 25, identify the Power Supply module.
(4)
Unscrew the four panel fasteners that secure the Power Supply module’s top cover. Remove the cover.
(5)
Using the illustration on page 25, identify link LK1. Ensure the link is set to suit the local ac input supply.
(6)
Refit the Power Supply module’s top cover.
(7)
Refit the drive unit’s top cover.
Page 24
2750M Drive Unit
(GA9976)
Power Supply Module – Location
Power Supply module’s PCB (looking from the top) showing location of ac mains selector link LK1. The link must be correctly set for either 115 V or 240 V operation.
(SA2351)
2750M Drive Unit
Link LK1 – Location
Page 25
SUPPLY FUSES Two fuses are fitted to the equipment’s rear panel: the ac input supply fuse, and the dc input supply fuse.
The ac input supply fuse F2 is fitted in the ac input connector.
ac supply fuse
For a 115 V ac input supply, a 1 amp anti-surge fuse should be fitted (PAE part number 29-01060103). or, For a 240 V ac input supply, a 500 mA anti-surge fuse should be fitted (PAE part number 29-01050102). (SA2358)
A dc input supply fuse F1 is fitted to the rear panel. A 3.15 amp anti-surge fuse should be fitted (PAE part number 29-01470102S).
AC INPUT CONNECTION WARNINGS! This equipment must be earthed. The earth terminal of the ac connector should be used as the safety earth. A chassis stud marked is fitted to the drive unit’s rear panel. This stud is used for connecting the drive unit to the equipment rack, or to the user’s system earth point. The stud is not intended to be used as the safety earth. The AC Input connector (with integral fuse) is fitted to the equipment’s rear panel as shown in the illustration on page 27. The minimum rating of the ac supply cable is: 3-core (to IEC 227) rated 250 V ac at 8 amps, and having a minimum cross-sectional area of 1.0 mm 2 per core. PAE recommends the use of polyvinyl chloride (PVC) cable. The cable must be fitted with an IEC approved equipment connector (PAE part number 20-02030102), and conform to the following specification:
If PVC insulated, be not lighter than ordinary polyvinyl chloride sheathed flexible cord according to IEC publication 227 (designation H05 VV-F, or H05 VVH2-F).
If rubber insulated, be of synthetic rubber and not lighter than ordinary tough rubber-sheathed flexible cord according to IEC Publication 245: Rubber Insulated Cables of Rated Voltages up to and including 450/750 V, (designation H05 RR-F).
The 2750M drive unit is a Class 1 equipment. The ac supply cable must have a green-and-yellow protective earthing conductor electrically connected to the protective earthing terminal of the equipment connector, and the mains plug. PAE recommends the ac supply cable is colour coded in accordance with the electrical appliance (colour code) regulations for the UK. That is:
Page 26
Line: Brown
Neutral: Blue
Earth: Green-and-yellow.
2750M Drive Unit
The cores of the power supply cable should be connected to the equipment connector provided, and your plug as follows:
The core that is coloured green-and-yellow must be connected to the terminal in the plug marked with the letter E or by the earth symbol or coloured green-and-yellow.
The core that is coloured blue must be connected to the terminal marked with the letter N or coloured black.
The core that is coloured brown must be connected to the terminal marked with the letter L or coloured red.
(GA10621)
Chassis AC Input Connector
DC INPUT CONNECTION The DC Input connector is fitted to the equipment’s rear panel. The recommended minimum rating of the dc supply cable is: 2-core, having a cross-sectional area of 1.5 mm 2 per core. The supply cable must be fitted with an XLR3 connector (PAE part number 20-01030106). The two top pins, as marked in the illustration on page 16, are used to connect the dc supply; the third (bottom) pin is unused.
CONNECTING THE CHASSIS STUD TO EARTH A chassis stud, marked is fitted to the controller's rear panel. In order not to compromise the equipment’s EMC the chassis stud must be connected to the user's system earth. The connection should be made using a single tri-rated, green-and-yellow cable having a cross-sectional area of 2.5 mm2. The cable should have CSA and UL1015 approval, and be connected to the chassis stud through an M6 eyelet. The cable can be crimped, or soldered, to the eyelet. Failure to comply with this instruction could result in non-compliancy with the European Commission EMC Directive 89/336/EEC.
2750M Drive Unit
Page 27
RF DRIVE CONNECTION A coaxial connection must be made between the drive unit’s rear panel RF Drive connector CN2, and the 2750SA transmitter’s rear panel EXT Drive Input connector.
FACILITIES CONNECTOR CN3 The Facilities connector socket (CN3), fitted to the equipment’s rear panel, provides control and monitoring signals that can be configured by the user as required. The connector’s signals are described in Table 1. When making connections to the Facilities connector, and in order not to compromise the drive unit’s Electromagnetic Compatibility (EMC), users must:
use a D-Type connector that has a screened cover (see illustration on page 29)
use screened multi-way cable, with the cable’s screen connected to the Facilities connector’s shell or body.
When the lines, connected to CN3, go outside the building and there is a risk of lightning strikes, gas discharge surge protectors should be fitted across the lines to protect the drive unit.
Top row from right to left: pins 1 to 13 Bottom row from rightto left: pins 14to 25
Pin-Out for CN3 – Chassis Mounted 25-Way D-Type Socket
Page 28
2750M Drive Unit
FACILITIES CONNECTOR CN7 The Facilities connector plug (CN7), fitted to the equipment’s rear panel, provides control and monitoring signals to and from the associated 2750SA transmitter. The connector’s signals are described in Table 2.
Top row from left to right: pins 1 to 13 Bottom row from left toright: pins 14to 25
Pin-Out for CN7 – Chassis Mounted 25-Way D-Type Plug
Cable Screen Connection to D-Type Connector's Shell
2750M Drive Unit
Page 29
Table 1. Rear Panel Facilities Connector CN3 Signal
Page 30
Pin
Audio Line 1 Audio Line 2 PTT Signal BIT Alarm - 2750SA Transmitter Serial Data In (-)
1 2 3 4 5
Unregulated Supply 19 to 32 V dc External PTT 0V Wideband audio Input Tx Inhibit
6 7 8 9 10
PTT Relay (common) PTT Relay (normally open contact) Serial Data Out (+) Line Centre Tap Alarm BIT (DU)
11 12 13 14 15
Not Used Serial Data In (+) Data Ground 1 Not Used Tape Output
16 17 18 19 20
Not Used Normal/Wideband Select Not Used PTT Relay (normally closed contact) Serial Data Out (-)
21 22 23 24 25
2750M Drive Unit