Troubleshooting
SiENBE28-901
130
Air Cooled Refrigeration Condensing Unit
[Check 1] Check for Causes of Rise in High Pressure
Referring to the Fault Tree Analysis (FTA) shown below, identify faulty points.
Rise in high
pressure
Partly rise
in pressure
High piping
resistance
Faulty outdoor
unit electronic
expansion valve
Faulty high
pressure control
[In cooling]
If the indoor unit
electronic expansion
valve is throttled:
[In frosting]
If the outdoor unit electronic
expansion valve is
excessively throttled:
Faulty
control
Abnormal if a temp. difference
between inlet and outlet is over 10°C.
Faulty indoor unit
electronic
expansion valve
Faulty
control
Suction air
temperature of
the condenser
too high
Suction air
temperature
of the outdoor
unit too high
Degradation
in condensing
capacity
Dirty condenser
Mixing of non-
condensing gas
Drop in
fan air
volume
Drop in
fan
output
High air
duct
resistance
Refrigerant
overcharged
Closed stop valve
Bended or crushed pipe
Clogged piping due
to foreign matters
Faulty valve coil
Faulty valve body
Faulty high pressure sensor
Faulty outdoor unit main PCB
Faulty valve coil
Faulty valve body
Faulty high pressure sensor
Faulty indoor
unit liquid pipe
thermistor
Faulty outdoor unit main PCB
Short circuit
High ambient temp.
←
Faulty fan
motor
Faulty outdoor
unit main PCB
(including
capacity setting)
Dirty filter
Obstacles
←
Check to be sure that the stop valve is open.
←
Visual check
←
Check for any temp. difference before and
after filter or branch piping.
←
Is the coil resistance and the insulation normal?
(See [Check 10])
←
Are the voltage characteristics normal?
←
Is the pressure value on the Service
Checker matched to the measurement of sensor?
←
Is the coil resistance and the insulation normal?
(See [Check 10])
←
Are the voltage characteristics normal?
←
Is the connector properly connected?
Are the thermistor resistance characteristics normal?
←
Is the pressure value on the Service
Checker matched to the measurement of sensor?
←
Is the suction temp. not more than 43°C?
←
Is the outdoor temp. not more than 43°C?
←
Does the heat exchanger get clogged?
←
Does air get mixed in the refrigerant circuit?
←
Can the fan motor be rotated by hand?
Is the resistance and insulation of motor
coil normal?
←
Is the capacity setting of spare PCB
correct, if used?
←
Does the air filter get clogged?
←
Is there any obstacle in the air duct?
←
See [Check 6].