TM 10-4610-232-12
Table 4-2. Unit Troubleshooting Guide (continued)
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
14. BACKWASH OUTLET valve light does not work. Light tests okay. BACKWASH OUTLET valve fight does not
show the actual valve position- (Reference Schematic Diagram FO-1, Sheet 7, schematic line 713).
Step 1. Check the actual position of the valve.
Refer to the “AUTOMATIC VALVES” general note and compare the actual position of the valve to
what its indicator light is showing.
Step 2. Check for damaged wires on the valve actuator. Check the limit switches on the valve actuator. Dis-
connect the valve electrical connector J38 and check for continuity across P38A and P38C when the
valve stem is retracted into the actuator housing (valve open).
Repair any damaged wires (para. 4-47).
(a) Replace the valve limit switch (LS3) (Reference Interconnection Diagram FO-2, Sheet 14) if
the actuating lever is broken or if there is no continuity across P38A/C (para. 4-47).
15. Clear/flush tank valve does not open (system clean). Valve light off (Reference Schematic Diagram FO-1,
Sheet 7, schematic line 735).
Step 7. Check valve for actual position. Refer to “AUTOMATIC VALVES” general note.
If valve is open, refer to valve light does not show correct valve position troubleshooting (malfunc-
tion 19).
Step 2. Disconnect the valve electrical connector P33. Check for 110-120 VAC across pins J33D and J33E
(Reference Interconnection Diagram FO-2, Sheet 14). If there is voltage present, notify direct sup-
port maintenance.
CAUTION
Even after closing the block valve in the next step there will be 85 psig (586 kPa) air in
the tubing to the automatic valve. Be careful when disconnecting the tubing at the
block valve. Slowly back off the tubing nut to allow air pressure drainage.
Step 3. Close the air Blockvalve at the air manifold for the clean/flush tank valve. Disconnect the air tubing to
the valve actuator. Check if the valve stem retracts into the actuator.
(a) If the stem retracts, repair the valve actuator by replacing the air control relay and solenoid
valve (para. 4-47).
(b) If the stem does not retract, or if it retracts with a jerky motion, replace the actuator (para. 4-47).
16. Clear/flush tank valve does not open during the last base of media filter backwasher . CLEAN/FLUSH OUT-
LET valve light off (Reference Schematic Diagram FO-1, Sheet 7, schematic line 735).
Step 1.
Step 2.
Turn off the raw water pump circuit breaker CB4 and the booster pump circuit breaker CB5 (Refer-
ence Interconnection Diagram FO-2, Sheet 10). Disconnect the backwash chlorine pump, connector
J45 (Reference 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
position and push INTIATE. The clear/flush tank valve should open when the raw water pump shuts
down near the end of the backwash cycle. Check valve for actual position (should be closed).Refer to
“AUTOMATIC VALVES” general note.
If valve is open, refer to valve light does tm show correct valve position troubleshooting (malfunc-
tion 19).
Disconnect the valve electrical connector P33. Check for 110-120 VAC across pins J33D and J33E
during the last phase of the backwash cycle (after the raw water pump shuts down).
(a) If there is voltage present, notify direct support maintenance.
(b) If there is no voltage present, go to step 3.
CAUTION
Even after closing the block valve in the next step there will be 85 psig (586 kPa) air in
the tubing to the automatic valve. Be careful when disconnecting the tubing at the
block valve. Slowly back off the tubing nut to allow air pressure drainage.
Change 1
4-57
