TM 11 5895-846-14
Section XII. MAINTENANCE OF ALARM MONITOR BZ-236/TSC
a. This section contains instructions and
illuminated, remove and replace the fault/safety gate
procedures for testing, fault isolation, removal and
module A1 is replaced, replace the alarm monitor and
replacement. The fault isolation procedures are based on
return it to the next higher level of maintenance (para 5-
the observation of front panel indicators and no
If replacement of the power supply PS1 or
additional support or test equipment is required.
fault/safety gate module A1 removes the fault, the
suspected assembly (PS1 or A1) is to be returned to
b. System Check.
45 for removal and replacement
of modules and
(1) During system operation, a SYSTEM
FAULT/CSS or RSS indicator may become illuminated.
If this occurs, place one or more of the fault switches
(under the front access cover) to the OVERRIDE position
to isolate the fault and clear the CSS or RSS fault
Dangerous voltages exist in this
equipment. Do not attempt any removal
(2) If any of the SAFETY ALERT alarms are
or replacement unless the equipment is
illuminated, it is necessary to open the alarm monitor
in a non-operating condition and all
drawer to test the override circuit. Loosen the four
power circuit breakers on the power
captive screws on the front panel.
distribution panel are in the OFF
(3) Open the alarm monitor drawer. The
SAFETY ALERT switch is located just behind the front
Testing and Fault Isolation
(4) Operate the SAFETY ALERT switch to the
OVERRIDE position; the SAFETY ALERT indicators
Power Supply Check.
should turn off. Release the switch. (5) If the indicators
do not turn off in either steps (1) or (4) above, the
(1) Place the POWER circuit breaker to the
problem is in the fault/safety gate module A1; remove
ON position. Check that the AC indicator is illuminated.
(2) Check that the DC indicator is illuminated.
suspect module A1 to general support maintenance
(3) If the DC indicator is not illuminated,
replace the bulb. If still not illuminated, the problem is in
the power supply module PS1; proceed to step (4)
Removal and Replacement
below. If the indication is correct, proceed to step b
(4) Remove and replace the power supply