TM 10-4610-232-34
Table 2-1. Direct Support Troubleshooting (Continued)
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
Step 7. Shut down ROWPU and generator. Refer to electrical drawings in Appendix E. Check continuity, point-to-
point, from transformer T1(X1) (REF: Interconnection diagram FO-2, Sheet 10) to J11A (REF: Interconnection
diagram FO-2, Sheet 9). Repeat the procedure from T1(X2) to relay K15(K2) (REF: Interconnection diagram
FO-2, Sheet 7). Remove the K1/K2 wires on K15 before testing.
(a) Repair any loose or damaged wires (para. 2-20).
(b) Replace circuit breaker CB7 or CB10 (REF: Interconnection diagram FO-2, Sheet 8) if either is open
(para. 2-23).
(c) Replace emergency stop PB3 (REF: Interconnection diagram FO-2, Sheet 11) if open (para 2-22).
(d) Replace/repair connector J11 if faulty (para. 2-21).
Step 8. Check continuity, point-to-point, from J11J to K15(K1). Depress the indicating plungers on K20 (REF:
Interconnection diagram FO-2, Sheet 6) and K15 when testing continuity across their contacts,
(a) Repair any loose or damaged wires (para, 2-20).
(b) Replace/repair connector J11 if faulty (para. 2-21).
(c) Replace relay K20 or K15 if their set of contacts does not show continuity when the indicating plunger
is depressed (para. 2-23).
(d) Replace relay K15 if all above checks are good (para. 2-23).
Step 9. Check continuity, point-to-point, from J11 K to TDK5 (REF: Interconnection diagram FO-2, Sheet 8) (terminal
4) and to relay K6(B3X) (REF: Interconnection diagram FO-2, Sheet 7).
(a) Repair any loose or damaged wires (para, 2-20).
(b) Replace/repair connector J1 (REF: Interconnection diagram FO-2, Sheet 14) if faulty (para. 2-21).
17. Feed pressure low light or horn does not work (Ref. Schematic diagram FO-1, sheet 9, schematic line 920 and schematic
diagram FO-1, sheet 10, schematic line 1009).
NOTE
Refer to malfunctions 16 and 18 for additional troubleshooting. Also, see light test and
alarm circuit troubleshooting.
Step 1. Shut down ROWPU and generator. Refer to electrical drawings in Appendix D. Remove the wires from
A2Y/A2X and A4Y/A4X on relay K15 (REF: Interconnection diagram FO-2, Sheet 7). Check for continuity
across each contact with the indicating plunger of K15 out. Push the indicating plunger in and check that
there is no continuity across the contact.
If the continuity checks are not as noted above, replace relay K15 (para. 2-23).
Step 2. Check the wires that were removed in step 1 for looseness or damage at their preceding connections.
Repair any loose or damaged wires (para. 2-20).
18. Feed pressure low light is not on and the feed pressure is 13 psig or less, or light is on and the feed pressure is 10 psig or
higher.
Test feed pressure low switch (PSL4) (REF: Interconnection diagram FO-2, Sheet 14) for accuracy. Disconnect J24
(REF: Interconnection diagram FO-2, Sheet 14) from the pressure switch panel. Disconnect the pressure sensing line
from the switch. Remove the cover on the switch and tag/remove the wires from the pressure switch. Check for
internal water leakage. Set a multi meter to the Ohms x 1 scale and attach the leads to the switch terminals that wires
#324 and #330 (N/O) were on. Connect a dead-weight tester or another known calibrated pressure control device to
the switch pressure (or inlet) port. The multimeter should read infinity with no pressure on the inlet pressure port.
Slowly apply pressure to the switch. The switch should close on an increasing pressure of 5 to 7 psig. Take the
pressure up to 20 psig and then slowly relieve it. The switch should open at 5 to 7 psig on decreasing pressure. If
adjustment is necessary the decreasing pressure actuation point takes precedence. The increasing pressure
actuation point can be somewhat outside the range given without causing problems to the ROWPU.
(a) Replace the switch if there is internal leakage (para. 2-27).
(b) Adjust the switch to the correct setting if it does not actuate as described above. Remove the
adjustment cover and turn the adjuster clockwise to increase the actuation point, counterclockwise to
lower it (para. 2-29).
2-28
Change 1
