9
POSSIBLE CAUSES
CORRECTIVE ACTION
A) Water downstream of dryer
1. Residual free moisture remaining in downstream
pipelines
2. Air by-pass system is open
3. Inlet and Outlet connections are reversed
4. Temperatures surrounding air lines downstream of
dryer have dropped below dryer's dew point rating
5. Excessive free moisture (bulk liquid) at dryer inlet
6. Condensate not being automatically drained
Drain mechanism is clogged or inoperative.
Drain line is restricted or frozen.
Electric drains - timer not set to allow for
sufficient condensate removal
7. Dryer overloaded resulting in elevated dew point.
8. Refrigeration system not functioning properly
resulting in elevated dew point.
1. Excessive air flow
2. Freezing of moisture in evaporator because of
refrigeration system improperly functioning.
3. Separator filter clogged
(Models RHP64, RHP93, RHP100 & RHP178)
1. Dryer overloaded resulting in high air outlet
temperature.
2. Refrigeration system not functioning properly
resulting in high air outlet temperature.
3. Unit functioning normally but thermostatic switch
is malfunctioning or not securely mounted.
a. Power failure
b. Line disconnect switch open
c. Blown fuses, open breaker
d. Faulty wiring, loose terminals
a. Refrigeration compressor not running
b. High inlet air temperature
c. High ambient air temperature
d. Hot gas by-pass valve improperly set
a. Hot gas by-pass valve improperly set
b. Low on refrigerant
a. High or low ambient conditions
b. Air-cooled models - Dirty, clogged condenser
fins, obstructed air flow across condenser, or non
functioning fan motor or fan control switch.
c. Water-cooled models - Cooling water temperature too
high, or flow too low, faulty water regulating valve,
clogged water strainer.
• Blow out system with dry air
• Check valve positions
• Check for correct connection
• Insulate or heat trace air lines exposed to low
ambients or dry air to lower dew point
• Install separator ahead of dryer
• Replace drain mechanism if inoperative
• Open drain line
• Electric drains - reset time so that all liquid is
discharge
• Check inlet air temperature and pressure, flow
rate (compressor capacity) and ambient air or
water temperature.
• See D below
• Check flow rate
• See D below
• Replace filter sleeve
• See A 7
• See D below
• Contact qualified refrigeration repairman or
manufacturer’s service department
• Check power to unit
• Close disconnect switch
• Check for continuity
• Have electrician check electrical connections
• Contact qualified refrigeration repairman or
manufacturer’s service department.
• Contact qualified refrigeration repairman or
manufacturer’s service department.
• Check minimum /maximum temperature ranges
• Clean condenser and check for free air flow, if
problem persists contact qualified refrigeration
repairman or manufacturer’s service department.
• Clean strainer, check water flow and temperature,
if problem persists contact qualified refrigeration
repairman or manufacturer’s service department.
3. Refrigerant compressor cycles on and off
2. Models RHP64, RHP93, RHP100, &
RHP178 - Refrigerant Suction Pressure
Gauge in red area
B) High pressure drop across dryer
SYMPTOM
Models HP64, RHP93, RHP100, & RHP178 -
Refrigerant Suction Pressure Gauge in blue
area
TROUBLESHOOTING GUIDE
D) Refrigeration system not functioning
properly
1. Power on light off
C) High Temperature Alarm
