IOM SYSCREW AIR EVO HSE

78
The table below lists the anomalies of operation of the unit, the relevant causes and the corrective measures. For anomalies of any other type or
not listed, contact one of authorised Service Centre for technical assistance.
Anomaly Cause Operation
The unit continues
to work, but
without cooling
Insufficient charge of refrigerant. Refill.
The dehydrating filter is clogged. Replace.
Ice on the suction
line
Wrong calibration of overheating.
Increase overheating.
Check the charge.
Excessive noise
Vibration of lines. Check the clamping brackets, if any.
Whistler emitted by the thermostatic
expansion valve.
Refill.
Check the dehydrating filter.
Noisy compressor.
Seized bearings; replace the compressor.
Check that the compressor’s locknuts are tightened.
Low oil level in the
compressor
One or more gas or oil leaks in the circuit. Identify and remove leaks.
Mechanical failure of the compressor. Request the intervention of a Service Centre.
Anomaly of the oil heater of the
compressor’s base.
Check the electric circuit and the resistor of the heater of the motor base,
and replace defective components.
One or both
compressors are
not working
Breaking of the electric circuit.
Check the electric circuit and detect any ground dispersions and short
circuits. Check fuses.
Intervention of the HP pressure switch.
Reset the pressure switch and the control panel and restart the appliance.
Identify and remove the cause that enabled the pressure switch.
The fuse of the control circuit is broken. Check for ground dispersions and short circuits. Replace fuses.
Loosened terminals. Check and tighten.
Halt caused by thermal overload of the
electric circuit.
Check the operation of check and safety devices. Identify and remove the
cause.
Wrong wiring. Check wiring of check and safety devices.
The line voltage is too low.
Check voltage. If problems regard the system, solve them. If they are
caused by the distribution network, inform the Energy Distributor.
Short-circuit of the compressor’s motor. Check the continuity of the winding.
Seized compressor. Replace the compressor.
Activation of the
LP alarm, stop of
the unit
Gas leak. Identify and remove the leak.
Insufficient charge. Refill.
Failure of the pressure switch. Replace the pressure switch.
Activation of the
HP alarm, stop of
the unit
Failure of the pressure switch. Check the operation of the pressure switch, replace it if defective.
The delivery valve is partially closed. Open the valve and replace it, if faulty.
Substances with condensable gases in the
circuit.
Drain the circuit.
The fan of the condenser is stopped. Check cables and motor. If defective, repair or replace.
The liquid line is
too hot
Insufficient charge. Identify and remove the cause of the loss of charge and refill.
Frosting of the
liquid line
The valve of the liquid line is partially closed. Check that valves are open.
The liquid filter is clogged. Replace the cartridge or the filter.
Compressor with
Frequency Inverter
(FI) not available
Communication between Fequency Inverter
(FI) and unit control board interrupted
Check that the data cable from unit control board to FI is not defective and
the connection is well tightened
Check that the FI power supply cables are not defective and the
connection is well tightened
Check that the main supply voltage is inside the permitted range of
application
Check that the control transformer for auxiliary supply is not defective and
the connection is well tightened
The unit control board is defective Change of control board
The Frequency inverter is defective Change of Frequency Inverter
10 - Troubleshooting