Welbilt FB081TF, Service Manual

Page: 47 / 96

Part Number REV00 04/08/2020 47
Section 5 Troubleshooting
Refrigeration System Diagnostics
REFRIGERATION SYSTEM CHECKLISTS
INSTALLATION/VISUAL INSPECTION CHECKLIST
Inadequate Clearances
• Check all clearances on sides, back and top.
Condenser is dirty
• Clean the condenser
Inadequate Water supply
• Refer to water system checklist
Ice machine is dirty
• Clean ice machine - excessive operational noise will
normally be corrected with cleaning. Infrequent
cleaning may need an overnight soak with ice machine
cleaner to remove all lime/scale deposits.
ANALYZING DISCHARGE PRESSURE OR TEMPERATURE
1. Determine the ice machine operating conditions:
• Air temperature entering condenser
• Air temperature around ice machine
• Water temperature entering water reservoir
2. Refer to 24-Hour Ice Production/Refrigeration Pressure/
Temperature Chart on page 85 for ice machine being
checked.
Use the operating conditions determined in step 1 to find
the published normal discharge pressure/temperature and
compare to actual measurements.
3. Measure the actual discharge pressure/temperature.
4. Compare the measurements (step 3) with the
published pressure/temperature (step 2).
Measurements will fall within the published range on
normally operating ice machines.
Discharge Pressure/Temperature High Checklist
Problem Cause
Improper installation Refer to Installation procedures.
Restricted condenser
air flow Dirty air filter
High inlet air temperature
Condenser discharge air recirculation
Dirty condenser fins
Defective fan motor
Defective fan cycle control
Improper refrigerant
charge Overcharged
Non-condensable in system
Wrong type of refrigerant
Other Non-OEM components in system
High side refrigerant line/component
restricted (before mid-condenser)
Discharge Pressure/Temperature Low Checklist
Problem Cause
Improper installation Refer to Installation procedures.
Improper refrigerant
charge Undercharged
Wrong type of refrigerant
Other Low ambient temperature
High side refrigerant lines/component
restricted (before mid-condenser)
Suction pressure is too low and affecting
discharge pressure. (Refer to “Suction
Pressure/Temperature Low Checklist.”)
No water or insufficient pressure
Starving expansion valve
Defective compressor
Moisture in refrigeration system
Defective fan cycle control
NOTE: Do not limit your diagnosis to only the items listed in
the checklists.