Dantherm AC-24, Service Manual

Page: 42 / 52

Fault finding
Malfunctions that might occur in the operation of the air conditioner are listed in the table
below. Reference to actions required to restore the air conditioner to normal op-erating
condition are also indicated.
If the air conditioner should malfunction, find the problem in column 1. Columns 2 and 3
describe the possible causes and corrective actions. The list of problems, causes, and remedies
will only give an indication of where a possible problem can be and what actions are needed to
correct the problem.
Problem  Cause  Action 
Air conditioner does not
operate
Green indicator lamp on
control panel is not ON
No power input Check that the power cable is
correctly connected to power
source and unit. Check that
power source is turned on and
providing 1 x 230 V AC
The unit controller fuse is
blown. Replace fuse.
Location shown on page 28
Air conditioner (compressor)
does not operate.
Green and yellow HP/LP
indicator lamps are on, but
they switch off again after a
few minutes
High ambient temperature
resulting in HP pressure switch
cut-out The HP pressure switch will
automatically reset when
the ambient temp. has fallen
below 55 °C.
Reduced condenser airflow
perhaps combined with
ambient temperature just
below 55 °C Hereafter the unit will restart
Reduced evaporator airflow
perhaps combined with low
ambient temperature resulting
in LP pressure switch cut-out Clean evaporator coil and
airflow filter Check that the
grill at the air outlet are not
blocked
Faulty thermostatic valve A refrigeration engineer has to
replace the valve.
Air conditioner (compressor)
does not operate.
Green and yellow HP/LP
indicator lamps are on, and
they do not switch off after a
few minutes
Refrigerant leak on the cooling
circuit A refrigerant engineer has to
check on the problem
Compressor does not operate
Green and red THERMO RELAY
indicator lamps are on Compressor thermo relay has
cut off Press the reset button for
compressor on the control
panel (see section “Reset of
thermo relay”, page 28)
Thermostat controller is
switched OFF Turn on the thermostat
controller.
Press and hold
Fault finding guide
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