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RG66007967 - Rev 02
FAULT
ANALYSIS OF POSSIBLE CAUSES
CORRECTIVE ACTION
Low condensation pressure.
Fault in the transducers.
Check the transducers and verify that
the depressor on the Schrader valves
that they are connected to works
correctly.
Outdoor T too low and/or presence of
strong wind.
Mount the condensation control and/
or protect the unit from dominant
winds.
Low water T if in heat pump mode.
Make sure the thermal load is adequate
for the power of the unit.
Low evaporation pressure.
Low water flow rate.
Check the correct rotation of the
pumps. Check for pressure drops in
the water circuit. Check the tightness
of the one-way valve of the pump unit
(optional).
Malfunctioning
thermostatic
valve.
Check its opening, and adjust if
necessary, by heating the bulb by
hand. If there is no response, replace it.
Clogged
filter.
Pressure drops through the filter
must not exceed 2°C (saturation
temperature). Should it happen,
replace the filters.
Low condensation T.
Make sure the condensation control
works properly [if present].
Low refrigerant charge.
Check the charge by measuring the
sub-cooling; if it is below 2°C, charge
with refrigerant.
Frosted coil if in heat pump mode.
Check the correct defrost parameter
settings. Make sure the 4-way valve
works properly.
Low outdoor T if in heat pump mode.
Make sure the operating limits are
respected and eliminate possible by-
passes and air recirculation.
The compressor does not start.
Internal thermal protector tripped.
Check the status of the thermal contact
in models equipped with protection
modules. Identify the causes after
restarting.
Tripped circuit breakers or line fuses
after a short circuit.
Check the cause by measuring the
resistance of the individual coils and
the isolation towards the chassis before
re-connecting the power.
One of the HP or LP switches has
tripped.
Check the microprocessor and
eliminate the causes.
The phases in the distribution cabinet
have been inverted.
Check the phase sequence relay.
