User's Manual

P B L Tunnel Units 1 & 2
Maintenance Handbook
H/book Number:-60-056100HBKMFCC
Issue No:-2
Date:-04/01/2006
Page:-
55 of 63
5.2.10 24V Single Relay Board (80-008902)
5.2.10.1 Description
The General Purpose Relay Board allows the inversion of signals and the isolation of
circuits. It is equipped with a single dual pole change-over relay RL1, with completely
isolated wiring, accessed via a 15 way in-line connector.
The relay is provided with polarity protection diodes and diodes for suppressing the
transients caused by "flywheel effect" which can destroy switching transistors or induce
spikes on neighbouring circuits. It’s common use is to amalgamate all the alarm signals
into one, volts-free relay contact pair for the main alarm system.
Note that the board is available for different voltages (12 or 24V) depending on the type
of relay fitted at RL1.
5.2.11 24V Flat-Pack PSU (96-300002)
5.2.11.1 Description
The power supply unit is a switched-mode type capable of supplying 24V DC at
6.25Amps continuously. Equipment of this type typically requires approximately 4.0-5.0
Amps at 24V DC, so the PSU will be used conservatively ensuring a long operational
lifetime.
No routine maintenance of the PSU is required. If a fault is suspected, then the output
voltage from the power supply may be measured on its output terminals. This is typically
set to 24.5V.
All the PSU’s used in AFL Cell Enhancers are capable of operation from either 110 or
220V nominal AC supplies. The line voltage is sensed automatically, so no adjustment or
link setting is needed by the operator.
5.2.11.2 Technical Specification
AC Input Supply:
110 or 220V nominal
Voltage:
90 to 132 or 180 to 264V
(absolute limits)
Frequency: 47 to 63Hz
DC Output Supply:
Voltage: 24V DC (nominal)
22 to 26V (absolute limits)
Current: 6.25A