LCP
RG66006889-Rev.01
32
FAULT
Possible causes
Corrective actions
The unit does not start.
No power supply.
Check that power is being supplied
both to the primary and auxiliary
circuits.
The electronic card is cut off from
the power supply.
Check the protections.
Alarms have been triggered.
Check whether any alarms are
signalled on the microprocessor
control panel, eliminate the causes
and restart the unit.
The phase sequence is wrong.
Reverse two phases in the primary
power line after disconnecting
them upstream from the unit.
The compressor is noisy.
The compressor is rotating in the
wrong direction.
Check the phase sequence relay.
Reverse the phases on the
terminal board after disconnecting
the unit and contact the
manufacturer.
Presence of abnormally high
pressure.
Insufficient flow of air to the
condenser.
Check whether all the fans are
turning properly.
Check the air T at the condenser
inlet and make sure no back
suction occurs.
Check whether the effective RMS
voltage to the fans is the
maximum. If necessary, check the
pressure transducers via the
revolution speed controller, where
present [optional].
Check the cleanliness of the finned
coils.
Presence of air in the refrigerant
circuit, as revealed by the
presence of bubbles in the flow
indicator also with subcooling
values exceeding 5 °C.
Drain and pressurise the circuit
and check for leaks. Generate a
slow vacuum [longer than 3 hours]
until reaching a pressure of 15 Pa
and then recharge in the liquid
phase.
Unit overcharged, as revealed by a
subcooling of more than 8 °C.
Drain the circuit.
Thermostatic valve and/or filter
obstructed. These symptoms may
also occur in the presence of an
abnormally low pressure.
Check the temperatures upstream
and downstream from the valve
and filter and replace them if
necessary.
Insufficient flow of water in the
case of heat pump operation.
Check the water circuit for
pressure drops and/or whether the
pump is working properly [direction
of rotation]. Check the outgoing
water T and make sure it is less
than or equal to 45°C.
