TM 10-4610-232-12
Table 4-2. Unit Troubleshooting Guide (Continued)
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
Step 5. Check connectors J/P19, J/P34, and J/P62 (Reference Interconnection Diagram FO-2, Sheet 16), for
loose pins and for signs of arcing.
Replace any cable assembly that shows damage (para. 4-27 and 4-85).
Step 6. Check continuity, point-to-point, from P19A, P1 9B to J62B, P19C, and P19D to
J62D.Check each lead for shorts between phases and shorts to the ground wire. The reading should
be infinity for each check.
(a) Replace any cable assembly that shows open during continuity checks (para. 4-27 and
4-33).
(b) Replace an cable or connector that shows a short between phases or a short to ground.
(paras. 4-27 and 4-33).
(c) Repair any loose or damaged wires in the external electrical panel (para. 4-33).
(d) Replace any MOVS (Reference Interconnection Diagram FO-2, Sheet 16) in the external
electrical panel that show physical damage or are shorted to ground from the power terminal
(para. 4-33).
Step 7. Tag arid disconnect motor leads (T1, T2, T3). Set multimeter to Ohms x 1 scale and connect test
leads between each motor lead and the motor frame. Readings should be infinity for each step.
Replace pump/motor assembly if the meter reading is zero (para. 4-67).
Step 8. Set multimeter to Ohms x 1 scale and check for continuity between all pairs of motor leads, T1 and
T2,T1 and T3, T2 and T3. Readings should be zero or near zero for each step.
Replace pump/motor assembly if reading is infinity (para. 4-87).
Step 9. Check motor cable for continuity on each lead and fors shorrts between phases and ground.
Replace/repair the cable if open or shorted (para. 4-67).
Step 10. Disconnect P61 (Reference Interconnection Diagram FO-2, Sheet 16 ) from the outside junction box.
Check for approximately 9 VDC across pins J61A and J61B.
If voltage is not present, notify direct support maintenance.
Step 11. Check continuity, point-to-point, from P61 A to P61B (Reference Interconnection Diagram FO-2,
Sheet 16). Turn the distribution pump switch (SS1) on while testing.
(a) Replace switch SS1 if it shows open while testing (para. 4-87).
(c) Repair any loose or damaged wires.
(b) Replace cable and connector P61 if faulty (para. 4-87).
Step 12. Push the LIGHT TEST switch.
If the light comes on, notify direct support maintenance to troubleshoot the distribution pump cir-
cuits.
Step 13. Shut down the ROWPU. Shut down the generator. Refer to the electrical schematic Appx. l-1 and
interconnect diagram Appx. I-2. Check continuity, point-to-point, from connector P1 3D to P1 3E
(Reference Interconnection Diagram FO-2, Sheet 14).
(a) Repair any hose or damaged wires (para. 4-30).
(c)
(b) Replace any cable and connector that shows open during testing ( para. 4-27 and 4-30).
Replace PB1 (Reference Interconnection Diagram FO-2, Sheet 14 if it shows open during
testing (para. 4-30).
Step 14. Check continuity, point-to-point, from P13D to P13F. Depress PB2 (Reference Interconnection Dia-
gram FO-2, Sheet 14) when testing across its contact.
(a) Repair any hose or damaged wires (para. 4-30).
(b) Replace any cable and connector that shows open during testing (para. 4-27 and 4-30).
(c) Replace PB2 if it shows open during
Step 15. Check continuity, point-to-point, from P13G to P13H.
(a) Repair any hose or damaged wires (para. 4-30).
(b) Replace any cable assembly that shows open during testing (para. 4-27 and 4-30).
Step 16. Remove the wires from PL1 (Reference Interconnection Diagram FO-2, Sheet 14) and check for re-
sistance across its terminals. It should be zero or near zero.
Replace PL1 if it shows open (para. 4-30).
Step 17. Notify direct support maintenance if the problem cannot be isolated.
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