22
IOM / @DNOVA_THS-0508
8.
TROUBLESHOOTING
On the next pages you will find a list of the most common causes that may cause the package unit to fail
or malfunction. These causes are broken down according to easily identifiable symptoms.
You should be extremely careful when attempting to implement any of the
possible remedies suggested: overconfidence can result in injuries, even serious
ones, to inexpert individuals. Therefore, once the cause has been identified, you
are advised to contact the manufacturer or a qualified technician for help
.
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 fuses
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
Invert 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.
Invert 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
for
the
presence
of
obstructions in the condenser
section ventilation circuit
Check whether the condenser coil
surface is obstructed
Check the condensation control
device [optional]
Presence of air in the refrigerant
circuit,
as
revealed
by
the
presence of bubbles in the flow
indicator also with undercooling
values exceeding 5 °C
Drain and pressurise the circuit
and check for leaks. Evacuate
slowly [for more than 3 hours] until
reaching a pressure of 0.1 Pa and
then recharge in the liquid phase