31
502-3000 Series Ztron
TM
Point Level Control
Troubleshooting
5.5 Testing the
Relay Circuits
Using an ohmmeter, perform the following steps to check out
the relay circuits:
a. The relay circuits consist of double-pole double-throw
relay contacts brought out to terminal strips. When
the relays are operating properly, one pair of contacts
will be open with high or low level, and one pair will
be closed with high or low level. Refer to Figures 2-10
and 5-2.
Figure 5-2
Relay Circuit Operation
b. Relay operation may generally be heard as an audible
click when the background noise is not too high. Use
one of the methods shown in Figure 5-3 to determine if
the relay contacts are switching.
c. Difficulty in calibration can often be traced to improper
wiring of the relay terminals to an annunciator or
other panel device. Check the wiring against the relay
chart in Figure 2-10.
Figure 5-3
Relay Circuit Troubleshooting
