SPX HPD Series - High Pressure Alarm (Regenerating); Low Pressure Alarm (Regenerating); Temperature Under;Over-Range Alarm; Dew Point Under;Over-Range Alarm

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SYMPTOM POSSIBLE CAUSE(S) CORRECTIVE ACTION
Outlet Dew Point Alarm
Left Tower or Right Tower
1. Inlet air ow higher than the sizing
condition.
2. Liquids entering the dryer inlet.
3. Inlet air temperature higher than the
sizing condition.
4. Desiccant dusting.
5. Contaminated desiccant (e.g. with oil).
6. Heater temperature set too low.
7. Heating malfunction due to heater
failure or heater contactor failure.
1. Reduce inlet ow to sizing condition.
2. Check the inlet air line for liquids. Inspect prelter and
drain valve. Clean, repair or replace automatic drain valve.
3. Check the compressor aftercooler and cooling system.
Reduce inlet air temperature to sizing condition.
4. Check air pressure, airow and airow surges and correct
as necessary. Replace desiccant.
5. Check prelter and automatic drain valve. Replace prelter
element. Clean, repair or replace drain valve as necessary.
Consult factory concerning need for desiccant replacement.
6. Adjust controller set point.
7. Replace heater or heater contactor.
High Humidity Alarm
Left Tower or Right Tower
1. Desiccant bed overloaded.
2. Poor regeneration.
3. Moisture probe damaged or defective.
4. Loss of desiccant drying capacity.
1. Check inlet air ow rate, temperature and pressure. Higher
than design ow, and temperature, and lower than design
pressure will result in overloading of the dryer.
2. Verify proper purge ow. Verify heater operation and cur-
rent draw.
3. Examine sensor for physical damage and check control-
ler/sensor operation. Replace sensor or control board as
necessary.
4. Inlet air improperly ltered causing desiccant contamination
- examine lter elements and drains. Repair or replace as
necessary. Useful life of desiccant has been exceeded.
Heater Over-Temperature
Alarm
1. Insufcient purge gas ow.
2. Temperature sensor failure.
1. Check for proper purge ow, reset as required.
2. Repair and replace as required.
Heater Low-Temperature
Alarm
1. Heating malfunction due to heater
failure or heater contactor failure.
2. Temperature sensor failure.
1. Replace heater or heater contactor.
2. Repair and replace as required.
Energy Management Under-
Range Alarm
or
Energy Management Over-
Range Alarm
1. Energy Management sensor failure. 1. Check circuit for continuity. Repair or replace as neces-
sary.