User's Manual

Weehawken Tunnel VHF Repeater System
User/Maintenance Handbook
Handbook N.-Weehawken_VHF Issue No:-A Date:-05/08/05
Page:-
66 of 75
7.13 12 & 24V Relay Boards (20-001601 & 20-001602)
7.13.1 Description
The General Purpose Relay Board allows the inversion of signals and the isolation of circuits.
It is equipped with two dual pole change-over relays RL1 and RL2, with completely isolated
wiring, accessed via screw terminals.
Both relays are 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
relays fitted at RL1 and RL2.
7.13.2 Technical Specification
PARAMETER SPECIFICATION
Operating voltage: 8 to 30V (floating earth)
Alarm Threshold: Vcc - 1.20 volt +15%
Alarm output relay contacts:
Max. switch current: 1.0Amp
Max. switch volts: 120Vdc/60VA
Max. switch power: 24W/60VA
Min. switch load: 10.0µA/10.0mV
Relay isolation: 1.5kV
Mechanical life:
>2x10
7
operations
Relay approval: BT type 56
Connector details: Screw terminals
operational: :-10°C to +55°C
Temperature range
storage: :-40°C to +70°C