Table 3-1. Direct Support Troubleshooting - continued
TEST OR INSPECTION
BACKWASH PUMP ASSEMBLY
1. BACKWASH PUMP SHUTS DOWN AND/OR FAILS TO START (R.O. ELEMENT CLEANING).
High voltages in this equipment can cause serious injury or death. When applying power during a
test, take proper measures to ensure personal safety. Never work on electrical equipment unless
there is another person nearby who is familiar with the operation and hazards of the equipment and
who is competent in administering first aid.
Step 1. Check if circuit breaker CB2 and/or heater assembly are tripped
If circuit breaker or heater assembly is tripped, go to Malfunction 2, Backwash Pump Assembly.
Step 2. Check if other pumps operate.
If other pumps do not work, go to Malfunction 1, ROWPU Assembly
Step 3. Check if relay K2 is on.
If relay is not on go to step 7.
Step 4. Check voltage at BACKWASH PUMP jack, J2
If 208 VAC is measured in all three tests (A-B, A-C and B-D), go to step 6.
Step 5. Perform a continuity check of power circuit as follows, make additional point-to-point checks as necessary to
find defective components.
To check continuity through K2, it is necessary to close contacts by raising handles on side of relay.
L3, CB1 or J10C
L2, CB1 or J10B
L1,CB1 or J10A