TM 10-4610-232-12
Table 4-2. Unit Troubleshooting Guide (Continued)
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
Step 2. Remove the tubing from the backwash air solenoid valve outlet. Operate the ROWPU and check for air
leakage through the solenoid valve by placing finger over outlet of solenoid valve.
(a) If air is leaking through solenoid, disassemble and clean out the backwash air solenoid valve (para.
4-51).
(b) If cleaning does not stop the air leakage, replace the backwash air solenoid valve (para. 4-51).
Step 3. Isolate noise source.
Refer to individual troubleshooting for the noisy component.
HIGH PRESSURE PUMP ASSEMBLY STABLE LEVELS.
High pressure pump assembly stable levels leak air or will not pump up.
Visually confirm malfunction and notify direct support maintenance to repair/replace leaking stable
level.
NOTE
The ROWPU will operate satisfactorily without the stable level pressurized. The
results will be a slight vibration and noise increase in the equipment. Replacement
can be performed when sufficient downtime is available for replacement.
DISTRIBUTION PUMP.
1. Distribution pump motor hums but won’t turn.
Check ease of rotation of pump. Turn motor fan by hand.
(a) If the motor turns easily, refer to distribution pump electrical troubleshooting.
(b) If the motor turns hard or not at all, replace the pump/motor assembly (para. 4-87).
CAUTION
If the pump has been subjected to freezing conditions, make sure that the pump does
not have ice in it. Warm it thoroughly.
2. Distribution pump noisy.
Step 1. Check mounting hardware.
(a) Tighten mounting hardware, if loose.
(b) Notify direct support maintenance.
3. Distribution pump assembly leaks.
Step 1. Check the pump shaft or casing for leaks.
Replace the pump/motor assembly (para. 4-87).
Step 2. If other components/piping are leaking.
Replace/repair leaking components/piping (para. 4-87).
4. Distribution pump runs but doesn’t pump or has low water flow.
Step 1. Check pump rotation. Rotation is clockwise from the fan end.
Rewire pump motor for correct rotation by interchanging the T1 and T2 leads in the motor junction box
(para. 4-87).
Step 2. Check distribution nozzles for broken parts or plugging.
Replace distribution nozzles (para. 4-86).
Step 3. Check suction hoses for plugging or collapsed liners.
(a) Replace hoses with collapsed liners.
(b) Remove anything that might be plugging hoses.
4-33
