ESIE15-08B
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Part 2. Troubleshooting
3. Symptom based troubleshooting
19/07/16
Page 61
Daikin Altherma Monobloc CA
Compressor frequency limited
- suction pipe superheat pro-
tection function active.
This protection control acti-
vates when suction superheat
is > 10°C and expansion valve
is fully open (480 pulse). Unit
returns to normal operation
when suction superheat is
< 4°C.
Remark: check the suction
superheat by measuring the
suction temperature (with con-
tact thermometer) before the
compressor and comparing
with the saturated evaporation
temperature.
Activation of the protection
function can be caused by var-
ious reasons, therefore we
recommend to check the fol-
lowing:
•
Check refrigerant charge
•
Check expansion valve for
correct operation (see
page 97) and check
suction thermistor (see
page 88).
• Check
the
refrigerant
circuit for blockages.
Based on the diagnosis exe-
cute one of the following
actions:
• Correct
the
refrigerant
charge (total charge:
1.8 kg)
•
Replace expansion valve
(see page 131) or suction
thermistor (see page 124)
• Remove
detected
blockages from the
refrigerant circuit
Root cause category: installation
PHE condenser (water side)
(partial) blockage.
Dirty water (particles).
•
Check water flow rate
registered by flow sensor.
•
Check water side plate
type heat exchanger for
blockage (see page 77).
•
If required replace the
water plate type heat
exchanger.
•
Check the water quality.
Root cause category: component - mechanical
Limited heat exchange
between refrigerant loop and
heat sink inverter could result
in high inverter temperatures
and limited compressor fre-
quency.
• Bad
contact
between
refrigerant loop and
inverter heat sink.
• Lack
of
refrigerant.
Check contact between refrig-
erant loop and inverter PCB
heat sink.
Root cause category: component - electrical
Discharge thermistor - higher
temperature measured than
actual.
Deviation of thermistor (higher
temperature measured than
actual).
Check discharge thermistor
(see page 88).
Replace discharge thermistor
(see page 124) or hydro PCB
A1P.
Heat sink inverter thermistor -
deviation.
Deviation of thermistor (higher
temperature measured than
actual).
Check heat sink inverter ther-
mistor (see page 88).
Replace heat sink inverter
thermistor (see page 124) or
hydro PCB A1P.
Expansion valve incorrect con-
trol - superheat too high.
•
Faulty suction thermistor.
•
Faulty low pressure liquid
thermistor.
•
Faulty expansion valve
control.
• Check
suction
thermistor
(see page 88).
•
Check the expansion valve
(see page 97).
Replace suction thermistor
(see page 124) or replace
expansion valve (see
page 131).
Possible failures
Root cause
Check
Corrective action
