Aircel DHT-40 - Page 35

VF, DHT, AES Series Manual |
Refrigerated Air Dryer User Manual
31
Problem Probable Cause Remedy
Water downstream
and dryer system not
working properly or
not working (cont.)
Refrigeration compressor cycles on/o
and cannot maintain suction pressure,
dryer undersized
Check airow (cfm) and dryer capacity. Reduce airow
through dryer or replace with a larger rated cfm dryer
Shorted fan motor winding
Check fan motor with ohmmeter and refer to motor
specications for correct value. Check wiring
schematic to ensure proper wiring of fan motor.
Replace motor if required.
Fan motor overload or unit short cycling
Check circuitry against electrical schematic (wiring
diagram). Check for high refrigerant pressure or for high
ambient temperature.
Defective overload protectors (fuses or
breakers)
Check overload protectors and replace if necessary
Low voltage or 3-phase imbalance
Check incoming power supply, voltage must be within 8%
to 12% of rating on the serial plate label.
Low water ow or pressure to water-
cooled condenser
Check water ow and/or pressure and adjust according to
specications. Contact Technical Support for assistance.
Defective fan control cycling switch Replace fan control cycling switch
Low air pressure
downstream or high
pressure drop across
the dryer system
Optional pre-lter element dirty or
plugged
Replace lter element
Suction pressure below set point,
causing freezing in the dryer heat
exchanger*
Refrigeration controls may require adjustment; contact
Technical Support for assistance. Refrigeration circuit may
be low on refrigerant. Locate leak in refrigeration circuit,
repair, and recharge according to specications.
Incorrect sizing or restriction in
compressed air line piping
Check compressed air piping for restrictions. Check
piping size to verify if it has the capacity to handle the
rated scfm at present working pressure of compressed
air system.
*NOTICE: To conrm freeze-ups, shut system o for 20 minutes and allow to thaw. Air pressure in line should
come back to normal pressure.
7.7 AES Series Troubleshooting Guide