25
TROUBLE SHOOTING
Problem
Probable cause
Solution
Unit operates
continuously but
without performing
Insufficient refrigerant charge.
Top up the refrigerant fluid charge.
Clogged filter dryer.
Replace the filter.
Reduced output from one or both circuits
Check the 4-ways valves and change them if necessary.
Frozen suction line
The overheating setting on the thermostatic
expansion valve is too low.
Increase the setting.
refrigerant charge too low
Check the refrigerant fluid charge
Evaporator freezing
Filters clogged
Replace filters
Insufficient charge
Check the refrigerant fluid charge
Evaporator air intake temperature too low
Check the economiser setting.
Excessive noise
Vibrating pipe work
Attach the pipe work correctly.
Check the pipe work attachments.
Whistling noise from the thermostatic expansion
valve
Add the refrigerant charge.
Check and replace the filter dryer if necessary.
Noisy compressor
Check the pressure difference of the 4-ways valves.
No pressure increase
Seized bearings. Replace the compressor
Check the tightness of the compressor attachment nuts.
Low oil level in the
Presence of one or several oil or gas leaks in the
circuit
Locate and repair the leaks and add oil
compressor
Mechanical compressor damage.
Contact an approved Service Centre.
Crankcase oil heater resistance fault.
Check the electrical circuit and the condition of the
resistance. Replace defective parts if necessary.
One or both
compressors do not
operate.
No power at compressor
Check the electrical circuit and seek out any grounding
and/or short- -circuits. Check the fuses.
High pressure pressostat activated.
Reset the pressostat from the control panel and restart the
unit. Check for dirty condenser coil or defective fan
Control circuit fuse blown.
Check the control circuit and look for any grounding and/or
short-circuits. Replace the fuses.
Connection problem
Check the tightness of all the electrical connection
terminals.
Electrical circuits thermal protection cuts in.
Check the operation of the control and safety devices.
Check amperage of compressor and discharge pressure
Incorrect wiring.
Check the wiring of the control and safety devices.
Mains voltage too low.
Check the power line.If the problem is due to the network,
inform the Electricity Company.
Compressor motor short–circuited.
Check the continuity of the motor winding.
Compressor seized
Replace the compressor.
Low pressure
pressostat being
activated.
Presence of a leak.
Identify and repair the leak.
Insufficient refrigerant fluid charge.
Add refrigerant charge.
Low air volume on evaporator
check the blower and duct
High pressure
pressostat being
activated.
Incorrect operation of the high pressure pressostat. Check the operation of the pressostat. Replace it if required.
Outlet valve partially closed.
Open the valve. Replace it if required.
Non-condensable particles in the circuit.
Bleed the circuit
Condenser fan(s) not operating.
Check the wiring and the motors. Repair and replace if
required.
Liquid line too hot
Insufficient refrigerant charge.
Locate and eliminate the causes of charge losses and top
up the refrigerant fluid charge.
Liquid line frozen
Clogged filter dryer.
Replace the filter cartridge.
Summary of Contents for 100
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