T M 1 0 - 4 6 1 0 - 2 3 2 - 1 2
Table 4-2. Unit Troubleshooting Guide (Continued)
TEST OR INSPECTION
22. Media filter flush valve will not close in fitter backwash or when the MEDIA FILTER FLUSH valve switch is
pushed. Indicator light on (Reference Schematic Diagram FO-1, Sheet 7, schematic line 706).
Check valve for actual position. Refer to AUTOMATIC VALVES general note.
If valve is closed, refer to valve light does not show correct valve position troubleshooting (malfunc-
Disconnect the valve electrical connector J48. Check for 110-120 VAC across J48D and J48E.
If voltage is not present, go to step 6.
Reconnect J48 and check for 110-120 VAC across terminals 4 and 5 on the valve.
If no voltage is present at the terminals, replace the valve cable and connector (para. 4-47).
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.
Close the air block valve at the air manifold for the filter flush valve. Remove the air tubing from the
automatic 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 if (paras. 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 Reference Interconnection Diagram FO-2, Sheet 15) from the control panel
and check for 110-120 VAC across J14b and J14d (Reference Interconnection Diagram FO-2,
(a) If voltage is not present, notify direct support maintenance.
(b) If voltage is present, go to step 7.
Refer to the electrical schematic and check continuity, point-to-point, from P14b to J48D and from
P14d to J48E.
Replace the cable and connectors if faulty (para. 4-27).
W A R N I N G
Electrical high voltage can cause serious injury or death. Some tests performed in
troubleshooting require power to be connected. Always take proper measures to en-
sure personal safety.
Ensure that all circuit breakers are set. Refer to Appendix I for schematic and inter-
connection diagrams. Continuity and short circuit test arrangement for pump motor is
shown in Figures 4-3 and 4-4.
Several of the following procedures require that the ROWPU be set up in SYSTEM
NORMAL operating mode to check if the pump works properly. If it is known that the
pump functions properly in that mode it is not necessary to check again.