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31
SYMPTOM
POSSIBLE CAUSE(S)
CORRECTIVE ACTION
High Pressure Alarm
Left Tower or Right Tower Re-
generating
1. Faulty regenerating tower pressure
switch
2. Regenerating tower Depressurization
Muffler clogged.
3. Regenerating tower Depressurization
Valve failed to open.
4. Regenerating tower purge exhaust pip-
ing obstructed.
5. Regenerating tower Purge Exhaust
Valve failed to open.
1. Check pressure switch operation using tower pressure
gauge for comparison. Replace switch if defective.
2. Examine inner core and clean or replace as necessary.
3. Check valve operation. Repair or replace as possible.
4. Ensure piping is free of obstructions.
5a. Check for loss of pilot air - ensure manual drain valve on
bottom of pilot air filter is fully closed, ensure pilot air filter
cartridge is not clogged, ensure pilot air shut-off valve is
open.
5b. Check for purge pilot air solenoid valve failure. Check valve
operation. Repair or replace as necessary.
5c. Check for regenerating tower Purge Exhaust Valve failure -
examine valve and actuator for damage. Repair or replace
as necessary.
Low Pressure Alarm
Left Tower or Right Tower Re-
generating
1. Faulty left tower pressure switch.
2. Regenerating tower Purge Exhaust
Valve failed to close.
3. Regenerating tower Depressurization
Valve failed to close.
1. Check pressure switch operation using tower pressure
gauge for comparison. Replace switch if defective.
2a. Check for air flow out of regenerating tower Purge Valve or
exhaust piping indicating valve is not completely closed.
2b. Check for loss of pilot air - ensure manual drain valve on
bottom of pilot air filter is fully closed, ensure pilot air filter
cartridge is not clogged, ensure pilot air shut-off valve is
open
2c. Check for purge pilot air solenoid valve failure. Check valve
operation. Repair or replace as necessary.
2d. Check for regenerating tower Purge Exhaust Valve failure -
examine valve and actuator for damage. Repair or replace
as necessary.
3. Check for air flow out of regenerating tower Depressur
-
ization Muffler indicating valve is not completely closed.
Repair or replace as necessary.
Temperature Under-Range
or
Temperature Over-Range
Alarm
Left Tower or Right Tower
1. Tower temperature sensor failure.
Under-Range
è
Short circuit on sensor
Over-Range
è
Open circuit on sensor
1. Check temperature circuit for continuity. Repair or replace
as necessary.
Dew Point Under-Range
or
Dew Point Over-Range Alarm
Left Tower or Right Tower Re-
generating
1. Energy Management temperature sen-
sor (RTD4) failure.
1. Check temperature circuit for continuity. Repair or replace
as necessary.