TM 10-4610-232-34
Table 2-1. Direct Support Troubleshooting Guide (Continued)
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
3. Booster pump circuit breaker opens whenever booster pump is started. ROWPU shuts down when booster pump is
started. (Ref. Schematic diagram FO-1, sheet 5, schematic lines 540-542).
Check for short circuits.
Refer to circuit breaker troubleshooting (malfunction 2).
4. Booster pump motor hums but will not turn. (Ref. Schematic diagram FO-1, sheet 5, schematic lines 540-542).
Shut down ROWPU and generator. Refer to electrical drawings in Appendix E and check continuity, point-to-point,
from the power distribution block (PDB) (REF: Interconnection diagram FO-2, Sheet 10) to J21 (REF: Interconnection
diagram FO-2, Sheet 16) on the following lines. AL1 to J21A, AL2 to J21B, and AL3 to J21C. Depress the operating
plunger MS7 (REF. Interconnection diagram FO-2, Sheet 16) when checking across its contacts. Disconnect the J21
connector when testing.
NOTE
When checking continuity in the power circuits, it is important to watch the wire numbers
on each phase. Each wire is tagged identically on both ends, but in some instances, a #1
phase wire will enter the top of a starter or circuit breaker and come out the bottom of the
same device as a #2 phase wire. This is done to change the rotation of a motor so that its
associated pump will turn in the correct direction. Any two wires may be interchanged to
accomplish this rotational change.
(a) Repair any loose or damaged wire (para. 2-20).
(b) Replace circuit breaker CB5 (REF: Interconnection diagram FO-2, Sheet 10) if open on any phase
(para. 2-25).
(c) If an MS7 overload is open, replace it and continue troubleshooting to find cause (para. 2-25).
(d) If MS1 (REF: Interconnection diagram FO-2, Sheet 10) shows open on any phase, replace/repair the
starter (para. 2-25).
(e) Replace/repair J21 if faulty (para. 2-21 ).
5. Booster pump does not run in system “BACKWASH” position. (Ref. Schematic diagram FO-1, sheet 6. schematic lines
627-628).
Step 1.
Step 2.
Step 3.
Step 4.
Shut down the ROWPU and open the control panel. Restore power to the control panel. Turn off the raw
water pump circuit breaker CB4 and the booster pump circuit breaker CB5 (REF: Interconnection diagram
FO-2, Sheet 10). Disconnect the backwash chlorine pump, connector J45 (REF: Interconnection diagram
FO-2, Sheet 15). Drain the media filter down until water stops coming out of the top media filter drain valve.
Set the control panel up in system “BACKWASH” and push “INITIATE. Check that the indicating plungers
on relays K2 and K19 (REF: Interconnection diagram FO-2, Sheet 6) go in.
(a) If the plunger on K2 does not go in, refer to operation mode circuit troubleshooting (control circuits
malfunction 2).
(b) If the plunger on K19 does not go in, check that the clean/flush tank is full and then refer to clean/flush
tank level switch troubleshooting (malfunction 7).
Watch PL17 (REF. Interconnection diagram FO-2, Sheet 12), backwash air inlet valve light. When it turns off
the indicating plunger on relay K14 (REF: Interconnection diagram FO-2, Sheet 7) should go in. This relay
turns the booster pump on during backwash.
If PL17 does not go off, or if the light goes off and the plunger on relay K14 does not go in, refer to media
filter backwashing circuit troubleshooting.
Shut down ROWPU and generator. Refer to electrical drawings in Appendix D and check continuity,
point-to-point, from switch PB11 (1B1) (REF: Interconnection diagram FO-2, Sheet 11) to relay K22(A4Y)
(REF: Interconnection diagram FO-2, Sheet 6), Depress the indicating plungers on K14 and K19 when testing
across their contacts.
(a) Repair any loose or damaged wires (para. 2-20).
(b) Replace relay K14 or K19 if either has an open contact when testing (para. 2-23).
Remove the #243 wire on the MS7 (REF: Interconnection diagram FO-2, Sheet 10) coil and the #299 wire from
PB16 (REF Interconnection diagram FO-2, Sheet 12) before testing. Check continuity, point-to-point, from
relay K21 (A4Y) (REF: Interconnection diagram FO-2, Sheet 6) to wire #243 on the MS7 coil. Depress the
indicating plunger on relay K2 when testing its contact,
(a) Repair any loose or damaged wire (para. 2-20).
(b) Replace relay K2 if its contact does not close during testing (para. 2-23).
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