Fujitsu R407C Service Manual page 121

5. Others
LED display
Indoor Outdoor Remote
unit unit controller
Body PCB LED
LCD
LED 1 to 6
Normal Normal Normal
display display display
Error display Error display Error display
(Outdoor (Discharge
(Outdoor
unit error) sensor error) unit error)
Symptom that
Cause
can occur other
than title
The electronic expansion valve
opening of indoor unit is faulty.
The cooling ca-
Electronic expansion valve
pacities of in-
opening of the relevant indoor
door units
unit is out of control (open
except for the
excessively) during cooling
relevant indoor
operation.
unit are insuffi-
cient. Abnorm-
al sound is hea-
rd from indoor
unit.
Abnormal sound
Electronic expansion valve
is heard from
opening of the relevant indoor
indoor unit.
unit is out of control (open
Frost may form
excessively) after stopping
on the surface
cooling operation.
of the heat ex-
changer of the
relevant indoor
unit.
Electronic expansion valve
The heating ca-
opening of the relevant indoor
pacities of in-
door units unit is out of control (open
excessively) during heating
except for the
operation.
relevant indoor
unit are insuffi-
Electronic expansion valve
cient.
opening of the relevant indoor
Abnormal sound
unit is out of control (open
is heard from
excessively) when the indoor
indoor unit.
unit stop heating operation.
Discharge
Up/down (left/right) swing
temperature is
switching motor is faulty.
high.
Discharge
Liquid injection solenoid valve
temperature is
(SV1) is faulty.
high.
Remakes
High pressure gas bypass
solenoid valve (SV2) is faulty.
Compressor Oil return solenoid valve (SV3,
error SV4, SV5, SV6) is faulty.
Remakes
High pressure High pressure switch is faulty.
is high.
Remakes
The operation Pressure sensor (HP, LP)
of the ourdoor are faulty.
unit is abnormal.
Remakes
05-45
Check method
(Error state check method)
When the indoor unit power is
reset 5~10 times at a 2~3
minutes interval, the expansion
valve may close.
Coil resistance (red-white,
red-orange, brown-blue,
brown-yellow) : 100~200
When the electronic expansion
The area (heat exchanger) near
valve is open excessively, other
the air diffuser is cool even after
indoor units may not operate at
several minutes have elapsed
full capacity or a loud refrigerant
since the relevant indoor unit was
rushing sound may be generated.
stopped. (the gas pipe of the re-
levant indoor unit remains cold).
If the electronic expansion valve
of the stopping indoor unit re-
mains open, frost may form on
the surface of the heat exchanger
of the indoor unit and water leak-
age or other trouble may occur.
Turn off the power source of PCB
of the indoor unit to initialize the
electronic expansion valves for
several times. Put a 3-minute in-
terval between each initializations.
The electronic expansion valve
may return to normal.
The temperatuer of air flow as Turn off the power source of PCB
well as inlet pipe of the electronic of the indoor unit to initialize the
expansion valve of the relevant electronic expansion valves for
indoor unit is higher than those of several times. Put a 3-minute in-
other indoor units. terval between each initializations.
The electronic expansion valve
The temperatuer of inlet pipe of
may return to normal.
the electronic expansion valve
do not become low.
Up/down louver does not move For the left - right swing switching
motor, check the voltage across
even when a voltage (DC12V)
the terminal of CN11. (for wall
is applied to the terminal of CN10.
(for wall mounted and ceiling wall mounted and ceiling wall type:
type: CN6). Check the voltage CN7).
across the terminal.
When SV1 is faulty, the
When a voltage (AC220-240V) is
discharge gas temperature may
applied to CN7, the liquid
rise and a discharge temperature
injection solenoid valve outlet
error may be generated.
pipe is not cold.
Coil resistance : 1200~1500 .
When SV2 is faulty, the high
When a voltage (AC220-240V) is
pressure may rise and a high
applied to CN8, the high
pressure error may be generated.
pressure gas bypass solenoid
Coil resistance : 1200~1500
outlet pipe is not warm.
When SV3, SV4, SV5, and SV6
When a voltage (AC220-240V) is
do not operate normally, the oil
applied to CN9, CN10, CN11,
may not return to the compressor
and CN12, the outlet pipe of the
and compressor trouble may
respective solenoid valve (SV3,
occur.
SV4, SV5, SV6) does not
Coil resistance : 1200~1500
become hot.
When the pressure switch is
There is a voltage difference
faulty, protection control will not
across terminals 1-2 of CN42
even though the high pressure be performed even if the high
exceeds 3.0MPa. pressure rises and a high
pressure error may be generated.
Measure the pressure sensors
output voltage (between terminals
2 and 3 of CN33 and CN34) and
compare the result with the
pressure gauge indication.
Remarks
When the pressure sensors are
faulty, compressor steps and
protection control will not
be conducted properly.
Refer to 7-2-2 to find the correl-
ation between pressure and
and output voltage of the sensor.