PROBLEM
SYMPTOM(S)
No discharge from auto-
matic drain valves.
Inlet air temperature is
outside normal range or
reaches alarm set point.
Liquid water entering
dryer.
Excessive airflow (may
also cause high pres-
sure drop).
Refrigerant compressor
cut out by high
refrigerant discharge
pressure control.
Water
downstream of
Compressor cuts out
dryer.
on internal overload.
Compressor windings
read open or shorted.
HIGH EVAP light on
or
Dew point indicator in
red zone
Suction temperature
higher than 65°F.
Refrigerant discharge
temperature lower than
140°F.
DXR Series Dryers (Bulletin 553)
FIELD SERVICE GUIDE
POSSIBLE CAUSE
Drain valve failure or accumulation
of dirt in valve.
Aftercooler malfunction.
Aftercooler drain valve malfunction.
Dryer improperly sized.
1. Condenser fouled or clogged.
2. Fan motor stopped.
3. Inlet air temperature too high.
4. Air in refrigeration system.
5. Ambient air temperature too high
for air-cooled compressor.
6. Aftercooler coolant air blowing
on air-cooled condenser.
1. Inadequate ventilation of air-
cooled compressor.
2. Insufficient cooling water for
water-cooled compressor.
3. Leak in refrigeration system.
4. Incorrect adjustment of refrigera-
tion control valves.
Compressor burned out.
1. Leak in refrigeration system.
2. Improper adjustment of HGBV.
3. Air or noncondensables in refrig-
eration system. Possible leak in
chiller.
1. Improper adjustment of HGBV.
2. Inlet air temperature higher than
130°F.
3. Excessive airflow
4. Leak in refrigeration system.
Low ambient temperature.
REMEDY
Dismantle drain valve; clean, repair or re-
place. See Maintenance section.
Check aftercooler discharge temperature.
Reduce temperature to 120°F max.; reduce
airflow if temperature is above 100°F.
Dismantle aftercooler drain valve; clean, re-
pair or replace.
Check airflow and dryer capacity (see Table
8). Reduce airflow or resize and replace
dryer.
1. Clean condenser coils (see Mainte-
nance, Monthly).
2. Repair or replace fan motor.
3. Check aftercooler discharge temperature.
Reduce temperature to 120°F max.; reduce
airflow if temperature is higher than 100°F
(see Airflow section).
4. Have refrigeration mechanic locate and
repair leak. Recharge. Refer to data plate for
refrigerant type and quantity.
5. Vent compressor room to outside.
6. Baffle or vent to outside air.
1. Ensure adequate ventilation of the con-
densing unit (see Clearance). Motor will re-
start automatically when compressor is
cool.
2. Ensure adequate cooling water (see Ta-
ble 1). Motor will re- start automatically
when compressor is cool.
3. Locate leak. Repair and recharge. Motor
will restart automatically when compressor
is cool.
4. Call your local distributor.
Have refrigeration mechanic check and re-
place.
1. Locate leak; repair and recharge.
2. Remove cap from HGBV and screw out
HGBV ½-turn with an allen wrench to lower
suction temperature to the level listed in the
Refrigerant Flow section.
3. Locate leak; repair and recharge. If chiller
must be replaced, consult your local dis-
tributor.
1. Remove cap from HGBV and screw out
HGBV ½-turn with an allen wrench to lower
suction temperature to the level listed in the
Refrigerant Flow section.
2. Reduce aftercooler discharge tempera-
ture to design conditions (120°F max.).
3. Check airflow and system capacity. Re-
duce airflow or resize and replace system.
4. Locate leak; repair and recharge.
Consult your local distributor.
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