IX. TROUBLESHOOTING GUIDE (cont’d)
PROBLEM
POSSIBLE CAUSE/REMEDY
6. Condensing unit runs but short cycles on...
1. Overload Protector - See #4 Above
2. Thermostat - Differential Set Too Close
3. High Pressure “Cut-Out” Due To:
a) Insufficient Air or Water Supply - Check Air or Water
Supply To Condenser, Correct
b) Overcharge - Reduce Refrigerant Charge
c) Air In System - Purge
4. Low Pressure “Cut-Out” Due To:
a) Liquid Line Solenoid Leaking - Replace e
b) Compressor Valve Leak - Replace
c) Undercharge - Fix Leak, Add Refrigerant
d) Restriction In Expansion Device - Replace Device
7. Condensing unit operates for prolonged
1. Shortage Of Refrigerant - Fix Leak, Add Charge
periods or continuously.
2. Control Contacts Stuck or Frozen Closed - Clean Contacts or
Replace Control
3. Excessive Heat Load Placed Into Cabinet - Allow Unit
Sufficient Time For Removal Of Latent Heat
4. Prolonged or Too Frequent Door Openings - Plan or
Organize Schedule To Correct Condition
5. Evaporator Coil Iced - Defrost
6. Restriction In Refrigeration System - Determine Locations &
Remove
7. Dirty Condenser - Clean Condenser
8. Filter Dirty - Clean or Replace
9. Unit may need to be defrosted.
8. Start capacitor open or shorted or blown.
1. Relay Contacts Not Opening Properly - Clean Contacts or
Replace Relay If Necessary
2. Prolonged Operation On Start Cycle Due To:
a) Low Voltage To Unit - Determine Reason & Correct
b) Improper Relay - Replace
c) Starting Load Too High - Correct By Using Pump Down
Arrangement If Necessary
3. Excessive Short Cycling - Determine Reason For Short
Cycling (see #5 above) And Correct
4. Improper Capacitor - Determine Correct Size
9. Run capacitor open, shorted or blown.
1. Improper Capacitor - Determine Correct Size & Replace
2. Excessively High Line Voltage (110% of rated max) -
Determine Reason & Correct
10. Relay defective or burned out.
1. Incorrect Relay - Check & Replace
2. Incorrect Mounting Angle - Remount Relay In Correct
Position
3. Line Voltage Too High or Too Low - Determine Reason &
Correct
4. Excessive Short Cycling - Determine Reason (see #5 above)
& Correct
5. Relay Being Influenced By Loose Vibrating Mounting -
Remount Rigidly
6. Incorrect Run Capacitor - Replace With Proper Capacitor
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