Troubleshooting
Problem
The Compressor(s) and the
Evaporator Fan do not start
up.
The Compressor does not
start, but the Condenser
Fan operates.
Compressor Cycles (a
different one from those
that usually serve the
thermostat).
The Compressor operates
continuously.
Excessive head
pressure.
Very low head
pressure.
Excessive suction
pressure.
Very low pressure
suction.
Compressor no. 2
does not operate.
50
Analysis of the Cooling Service
Cause
Power failure.
Burnt fuse or tripper cutting circuit.
Defective thermostat, contactor, transformer or
control relay.
Insuffi cient line voltage.
Defective or incorrect cabling.
Very high setting of the thermostat.
Defective cables or loose connections in the
compressor circuit.
Burnt compressor motor, inside overload.
Defective operation/start up of the capacitor,
overloaded, start-up relay.
One power phase is dead.
Overload or low refrigerant charge.
Defective compresso.
Insuffi cient line voltage.
Locked condenser.
Defective operation/start up of the capacitor,
overloaded, start-up relay.
Defective thermostat.
Defective Condenser Fan or Capacitor.
Obstruction in the Refrigerant System.
Dirty air fi lter.
Undersized unit for the load.
Thermostat setting is too low.
Low refrigerant charge.
Valves with leaks in the compressor.
Air in the system.
Dirty or obstructed Condenser Coil.
Dirty air fi lter.
Dirty Condenser Coil.
Refrigerant overload.
Air in the system.
Obstructed or short cycle air in the condenser.
Low refrigerant charge.
Valves with leaks in the compressor.
Obstruction in the liquid tube.
High head charge.
Valves with leaks in the compressor.
Refrigerant overload.
Dirty air fi lter.
Low refrigerant charge.
Metering device or obstructed low side.
Insuffi cient evaporator air fl ow.
Very low temperature in the conditioned area.
Outside ambient below 8.9°F.
Unit in economizer mode.
Solution
Call the electricity company.
Replace the fuse or readjust the cutting circuit.
Replace the component.
Determine the cause and correct it.
Check the cabling diagram and perform a correct
cabling.
Set the thermostat at a temperature lower than the
ambient one.
Check the cabling and repair or replace.
Determine the cause. Replace the compressor.
Determine the cause and replace.
Replace the fuse or readjust the cutting circuit.
Determine the cause.
Recover the refrigerant, evacuate the system and
recharge the descriptive tray.
Determine the cause and replace.
Determine the cause and correct it.
Determine the cause and correct it.
Determine the cause and
replace.
Replace the thermostat.
Replace.
Locate the obstruction and remove it.
Replace the fi lter.
Reduce the load and increase the unit size.
Reset the thermostat.
Locate the leak, repair and recharge.
Replace the compressor(s).
Recover the refrigerant, evacuate the system, and recharge.
Clean the coil and remove the obstruction.
Replace the fi lter.
Clean the coil.
Recover the refrigerant excess.
Recover the refrigerant, evacuate the system and recharge.
Determine the cause and correct it.
Locate the leak, repair and recharge.
Replace the compressor(s).
Remove the obstruction.
Check the source and eliminate it.
Replace the compressor(s).
Recover the refrigerant excess.
Replace the fi lter.
Locate the leak, repair and recharge.
Remove the cause of the restriction.
Increase the air amount. Check the fi lter and
replace if necessary.
Reset the thermostat.
Install a low-ambient kit.
Proper operation. It does not require any solution.