TM 10-4610-232-12
Table 4-2. Unit Troubleshooting Guide (Continued)
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
Step 5.
Step 6.
Step 7.
Step 8.
Step 9.
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. Slowly back off the tubing nut at the block valve to
relieve air pressure before removing the air tubing at the automatic valve.
Close the airblock valve at the air manifold for the media filter outlet valve, Remove the air tubing from
the valve and check that air is being supplied to the valve by opening the air block valve.
If air does not come out the tubing with the air block valve open, find the blockage In the air tubing
and repair it (parse. 4-24 and 4-68).
Check the wiring on the valve for damage or looseness.
(a) Repair any damage to the wiring para. 4-47).
(b) If the wiring is okay, replace the air control relay and solenoid valve (para. 4-47).
Remove connector P14 from the control panel. Turnoff the raw water pump
circuit breaker CB4, the
booster pump circuit breaker CB5 Reference Interconnection Diagram FO-2, Sheet 10), and the
high pressure pump breaker CB6. Disconnect the backwash chlorine pump, connector J45. Set the
control panel up in SYSTEM CLEAN and push INITIATE. Check for 110-120 VAC across J14A and
J14B.
If voltage is not present, notify direct support maintenance.
Drain the media filter down until water stops coming out of the media filter top drain. Set the control-
panel up in system “BACKWASH” and push "INITIATE". Observe the BACKWASH AIR INLET valve
light on the control panel and check for 110-120 VAC across J14A and J14B when it comes on.
(a) lf the BACKWASH AIR INLET valve light does not come on, refer to “MEDIA FILTER-back-
washing circuit troubleshooting.
(b) If the BACKWASH AIR light comes on and there is no voltage, notify direct support mainte-
nance.
No power. Check for continuity from P14A to J41 D and from P14B to J41E.
Replace the cable and connectors as required (para. 4-27).
6. MEDIA FILTER OUTLET valve light does not work. Light tests okay. MEDIA FILTER OUTLET valve Iight does
not show the actual position (Reference Schematic Diagram FO-1, Sheet 7, schematic line 719).
Step 1. Check the actual position of the valve.
Refer to the general note on “AUTOMATIC VALVES” 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 for
damage. Disconnect the valve electrical connector J41 and check for continuity across P41A and P41
C when the valve stem is retracted into the actuator housing (valve open).
(a) Repair any damaged wires para. 4-47.
(b) Replace the valve limit switch (LS5) (Reference Interconnection Diagram FO-2, Sheet 15) if
the actuating lever is broken or if there is no continuity across P41 A/C (para. 4-47).
7. Backwash inlet valve will not open (system backwash position). Valve Iight off (Reference Schematic Diagram
FO-1, Sheet 7, schematic line 709).
Step 1. Check valve for actual positoin. Refer to “AUTOMATIC VALVES” general note.
If valve is open, refer to valve light does not show correct valve position troubleshooting (malfunc-
tion 10).
CAUTION
Even after closing the block valve in the next step there will be85 psig (586 kPa) air in
the tubing to the automatic valve. Slowly back off the tubing nut at the block valve to
relieve air pressure before removing the air tubing at the automatic valve.
Change 1
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