TM 10-4610-232-12
Table 4-2. Unit Troubleshooting Guide (Continued)
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
Step 2. Reconnect the connector checked in the last step and refer to the schematic to determine the next
connector in the circuit being tested. Disconnect it and check for voltage (110-120 VAC) across the
pins shown in the schematic.
If there is no voltage, replace the cable and connectors (para. 4-27).
Step 3. Check the receptacle and its wires for sheds and for continuity.
a Repair any hose or damaged wires.
b Replace any faulty receptacles (paras. 4-30,4-31,4-33 and 4-34).
DISTRIBUTION PUMP.
W A R N I N G
Electrical high voltage can cause serious injury or death. Some tests performed in
troubleshooting require power to be connected. Always take proper measures to en-
sure personal safety.
NOTE
Continuity and short circuit test hook ups for the pump are shown in Figures 4-1 and
4-2.
NOTE
Ensure that all circuit breakers are set before troubleshooting.
Distribution
pump won’t run (Reference Schematic Diagram FO-1, Sheet 8, schematic lines 831-837- control,
Reference Shematic Diagram FO-1, Sheet 5, schematic lines 524-529- power).
Step 1. Shutdown the ROWPU. Open the control panel. Check that the overload reset button on MS2 (Refer-
ence Interconnection Diagram FO-2, Sheet 10) is in by pushing it.
a
If the reset button is in, go to step 2.
b If the button is out and won’t reset, notify direct support maintenance to replace the overload
heaters on MS2 and then go to step 3.
(c) If the reset button is out but resets when pushed, notify direct support maintenance to adjust
the door reset assembly for MS2 and then go to step 3.
Step 2. Power up the control panel (para. 2-19). Turn the selector switch on the distribution pump “ON”. Push
the distribution pump “ON” switch at the back door. Watch the indicating plunger on MS2. It should go
in and stay in which indicates the control circuits are working properly.
(a)
(b)
(c)
(d)
If the distribution pump "power on” light at the back is on, the MS2 indicating plunger
did notgo in, go to step 10.
If the indicating plunger goes in but comes out when the distribution pump ON switch at the
backdoor is released, notify direct support maintenance to troubleshoot the distribution pump
circuits.
If the indicating plunger on MS2 goes in and stays in, go to step 3.
If the distribution pump “ON” light at the back door does not come on when the pump “ON”
Step 3. Shut down the ROWPU. Shut down the generator. Refer to the electrical schematic Appx. l-1 and
interconnect diagram Appx. I-2. Set ohmmeter to Ohms x 1000 scale. Check each lead, 2T1, 2T2,
and 2T3 from the outlet side of MS2 to ground. The reading should be infinity for each lead.
If the meter reading is zero there is a short circuit, go to step 5.
Step 4. Set the multimeter to Ohms x 1 scale and check for continuity between all pairs of leads; 2T2 and 2T2,
2T2 and 2T3, 2T1 and 2T3, Readings should be zero or near zero for each step.
If the checks performed in both steps 3 and 4 are okay, return the ROWPU to service.
4-80
Change 1
