Table 4-2. Unit Troubleshooting Guide (Continued)
TEST OR INSPECTION
Clean/flush tank low level alarm is on and tank water level is higher than the bottom flange. Problem only occurs when
high pressure pump is running.
Check high pressure pump stable levels.
(a) Increase air pressure in all four stable Ievels equally until tank vibrations cease to cause an alarm
(b) If the tank low level alarm keeps alarming, refer to level switch troubleshooting (malfunction 7).
MEDIA FILTER AIR BLANKET LEVEL INDICATOR.
1. Media filter air blanket level chamber is plugged (flags wont move).
Step 1. Check tubing lines connected to the level chamber.
Remove and clean out tubing lines, if plugged (para. 4-52).
Step 2. Check level chamber.
(a) Remove bottom of chamber and clean chamber (para. 4-52).
(b) Replace float if it is damaged (para. 4-52).
Step 3. Check float for magnetism by holding a steel object near it.
Replace float if no magnetic effect is shown (para. 4-52).
Step 4. Check flag assembly.
(a) Remove flag assembly and float from level chamber and slide the float up and down the flag
assembly (para. 4-52).
(b) Replace flag assembly if the flags dont move (para. 4-52).
2. Flags stick (not all flags turn).
Step 1. Check flag assembly clamps.
Loosen clamps until flags turn.
Step 2. Check operation of flags by removing the flag assembly and float and running the float up and down the
assembly (para. 4-52).
Replace flag assembly if all the flags dont turn (para. 4-52).
1. MEDIA FILTER PLUGGED light IS on at pressure differential less than 20 psi (138 kPa) or, is not on at a pressure
greater than 30 psi (207 kPa).
Operate unit and determine that malfunction is true.
Notify direct support maintenance to troubleshoot media filter differential pressure switch circuits.
2. Media filter output is greater than 5 NTU after reconditioning and backwash.
Step 1. Check inline turbidity monitor.
Refer to para. 2-5 and adjust the meter to the correct setting. Recheck media filter outlet turbidity after
Step 2. Check portable turbidity meter.
(a) Refer to para 2-6 and adjust the meter to the correct setting. Recheck media filter outlet turbidity
after adjusting meter.
(b) If both turbidity meters are indicating correctly, replace the filter media (para. 4-53).