Railway Equipment 934, Operating Manual

Page: 32 / 62

P/N R9340-0104 32 © 2010 RAILWAY EQUIPMENT CO.
REV B
5/11
VIII. SNOW DETECTOR
A.
SNOW DETECTOR INSTALLATION
1.
The snow detector sensing circuitry is contained within the control module. All
that is required for snow detector operation is to connect the sensing head(s).
2.
Either one or two sensing heads may be used.
3.
Each sensing head has three lead wires; black, white, and green. Connect as
follows:
a) green: one or both connected to TS1-9.
b) black #1: connected to TS1-11.
c) black #2: connected to TS1-12.
d) white: one or both connected to TS1-10.
NOTE: Refer to the diagrams when connecting wires for the sensing heads. It is
important to properly connect the sensing head wires. Improper connection of the
sensing head wires may result in damage to the control module and/or the sensing
head.
4.
To operate more than one HAB unit from a HAB unit that is controlled by a snow
detector(s), connect terminal posts #9 together and terminal posts #10 together.
(Do not connect terminal post #9 to terminal post #10.) When connecting snow
detectors to more than one HAB unit, first connect one HAB. Then connect the
snow detector to one more HAB. If the snow detector does not operate properly,
exchange L1 and L2 on the newest HAB circuit breaker. NOTE: BE SURE L1
AND L2 ARE DE-ENERGIZED BEFORE EXCHANGING THEM. Continue to
add HABs to the snow detector in the same manner until all the desired HABs are
connected. DO NOT EXCEED 200’ CABLE LENGTH (18 AWG WIRE).
5.
The sensing heads should be mounted in a vertical position.
6.
Experience has shown that positioning a snow detector sensing head in the switch
area between the ties and between the switch point and the track duct is effective.
A second sensing head is then placed away from the switch area, such as on a
bungalow or pole.