IOM / @DNOVA_THS-0508
23
FAULT
Possible causes
Corrective actions
Presence of abnormally high
pressure
Unit overcharged, as revealed by
an Sub-cooling 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.
Low condensation pressure
Transducer fault
Check
the
efficiency
of
the
condensation
control
device
[optional]
Low evaporation pressure
Malfunctioning
of
thermostatic
valve
Warming the bulb with your hand,
check whether the valve opens and
adjust it if necessary. If it does not
respond, replace it.
Filter dryer clogged
Pressure drops upstream and
downstream from the filter should
not exceed 2°C. If they do, replace
the filter.
Low condensation T
Check
the
efficiency
of
the
condensation control device [where
present]
Low level of refrigerant
Check the refrigerant level by
measuring the degree of Sub-
cooling; if it is below 2°C replenish
the charge
The internal thermal protection
device has tripped
In the case of compressors
equipped with a protection module,
check the thermal contact. Identify
the causes after restarting.
The compressor does not start
The circuit breakers or line fuses
have been tripped by a short circuit
Pinpoint the cause by measuring
the resistance of the individual
windings and the insulation from the
casing before restoring power.
One of the high or low pressure
switches has tripped
Check on the microprocessor,
eliminate the causes.
The phases have been inverted in
the distribution compartment
Check the phase sequence relay.