Table 3-2. Operator Troubleshooting (ROWPU) - cont.
TEST OR INSPECTION
BACKWASH WATER FLOW READING DROPS TO NEAR ZERO DURING BACKWASH OPERATION;
BACKWASH PUMP LAMP IS ON.
Step 1. Check water level in backwash water tank.
There is a period of about 15 seconds when the flow gauge will drop to "0" before returning to
normal reading. This is normal.
If water level is below backwash pump intake, immediately shut off backwash pump (set circuit breaker
CB-2 to off). Wait until backwash cycle is complete, then start normal operation and allow backwash
tank to fill. When backwash tank is filled, perform backwash cycle.
b. Patch any leaks in backwash water tank (refer to TM 5-5430-227-12&P/TO 37A12-1-121).
Step 2. Check for closed or clogged gate valve at backwash water tank (figure 2-37).
a. Open closed gate valve by turning handle fully to the left until it stops (counterclockwise).
b. Clean clogged valve.
Step 3. Check for clogged backwash strainer or BACKWASH PUMP suction opening.
Flush remove and clean backwash strainer screen (para. 3-6).
Step 4. Check for leaking hoses, gaskets and fittings.
Replace defective hoses and fittings.
Step 5. Check for kinked hoses.