Emerson 3000/ITR Manuel D’Utilisation

Compressor will not start

Power Off

Check main switch, fuses or CBs and 

wiring

Current overload open

Re-set units with overload option 

manually. Allow compressor to cool for 

internal overloads to reset.

Loose electrical connections

Tighten connections

Compressor motor burned out

Check and replace compressor if 

defective.

Compressor will not operate, 

contactor not pulling in

No call for cooling

Check monitor status.

Solenoid valve not energizing

Hold screwdriver over solenoid and check 

for magnetic field. This indicates solenoid 

is energized.

Low pressure switch not making contact

Check gas pressure - manually energize 

low pressure switch.

Compressor will not operate, 

contact not pulling in

High pressure switch open

Reset switch. Refer to other refrigeration 

troubleshooting suggestions.

Compressor contactor pulled in but 

compressor will not operate

Blown fuse or tripped CB

Check for line voltage after fuses or CBs, 

and after contactors.

Compressor runs for three minutes 

then stops; contactor drops out.

Low pressure switch not closing

Check for low gas pressure. Compressor 

is running on Positive Start Kit (air cooled 

systems only)

Liquid line solenoid valve not opening

Check magnetic field to see if energized.

High discharge pressure

Dirty condenser or drycooler fins

Clean coil.

Condenser equipment not operating

Check operation.

High refrigerant charge

Check refrigerant charge.

Hot gas bypass valve adjusted 

improperly

Adjust properly.

Water regulating valve adjusted 

improperly

Adjust properly.

Low discharge pressure

Excessive fluid flow through condenser

Adjust fluid regulating valve

Suction service valve partially closed

Open the valve.

Faulty head pressure control valve or 

condenser fan speed control

Replace if defective.

Compressor rotation in reverse direction

Check for proper power phase wiring to 

unit and to compressor motor.

Low suction pressure

Insufficient refrigerant in system

Check for leaks, repair, and add 

refrigerant for air cooled. Evacuate and 

recharge for water/glycol unit.

Dirty air filters

Change filters.

Plugged filter-drier

Replace filter.

Improper superheat adjustment

Reset expansion valve for 10-15

°

F 

(6-8°C)

Defective expansion valve sensing 

element

Replace element

Poor air distribution

Check duct work for closed dampers. 

Check for under-floor restrictions at or 

near the unit.

Low condensing pressure

Check head pressure control device.

Slipping belts

Inspect and adjust