Emerson 3000/ITR User Manual

Flooding

Defective or improperly set expansion 

valve

Increase superheat or replace valve

Evaporator fan motor or belt

Correct problem or replace fan motor and/

or belts.

Low condensing pressure

Check head pressure control device

Slipping belts

Inspect and adjust

Low compressor capacity or 

inability to pull down system

Compressor rotation in reverse 

direction.

Check for proper power phase wiring to 

unit and to compressor motor.

Leaking liquid line solenoid valve or dirt 

in valve

Replace valve if clean; clean out valve if 

dirty.

Compressor noisy

Loose compressor or piping support

Tighten clamps.

Pipe rattle

Loose pipe connections

Check pipe connections

Compressor running hot

Compression ratio too high

Check setting of high and low pressure 

switches. Check condenser -- is it 

plugged? Check that all evaporator and 

condenser fans are operating properly.

Compressor cycles intermittently

Low-pressure switch erratic in operation

Check tubing to switch to see if clogged or 

crimped. Check for proper switch 

operation.

Insufficient refrigerant in system

Check for leaks, fix, and add refrigerant on 

air cooled unit. Evacuate and recharge 

water/glycol unit.

Suction service valve closed

Open valve.

Insufficient fluid flowing through 

condenser or clogged condenser, or 

dirty air cooled condenser coils

Adjust fluid regulating valve to condenser. 

Flush the condenser.

Discharge service valve not fully open

Open valve

Compressor cycles continually

Faulty low pressure switch

Repair or replace.

Dirt or restriction in tubing to pressure 

stat

Check and clean tubing.

Defective liquid line solenoid valve

Check valve and solenoid operator; 

replace if necessary.

Plugged filter-drier

Replace filter.

Compressor motor protectors 

tripping or cycling

High discharge pressure

Check for loss of condenser water or 

blocked condenser fan or coil.

Defective overload relay

Replace.

High suction temperature

Reduce suction temperature by expansion 

valve adjustment or provide 

desuperheating.

Loose power or control circuit wiring 

connection

Check all power and control circuit 

connections.

Defective motor

Check for motor ground or short. Replace 

compressor, if either condition is found.

Compressor cycles on locked rotor

Low line voltage

Check line voltage and determine location 

of voltage drop.

Compressor motor defective

Check for motor winding short or ground.

Single phasing

Check voltage across all 3 legs at 

contactor. Correct source problem.

Motor burnout

Check control panel for welded 

contactor contacts or welded overload 

contacts

Replace defective components