Fujitsu R407C Service Manual page 116

LED display
Indoor Outdoor Remote
unit unit controller
PCB LED
Body
LCD
LED
1 to 6
Normal Normal
Normal
display display display
Error display Error display
Error display
(Outdoor (Communi- (Outdoor
unit error) cation error)
unit error)
Become normal after the power
is reset.
Normal Normal Normal
display display display
or
error display
(Compressor
error)
Error display Error display
Error display
(Thermistor (Indoor unit
(Thermistor
error) error)
error)
Normal Error display Normal
display (High display
pressure
error)
Symptom that
can occur other
Cause
than title
Installed piping is not suitable.
Abnormal sound
Liquid piping diameter is
is heard from
incorrect.
indoor unit.
Outdoor heat exchanger
switching 4-way valves (4WV2,
4WV3, 4WV4) or solenoid valves
(SV7, SV8) are faulty.
High pressure
Refrigerant additional charge
rises or falls is unsuitable.
abnormally.
Indoor~outdoor unit
communication line faulty.
Refrigerant is seriously insuffici-
ent.
The fan of the
Indoor thermistor is faulty.
indoor unit does
not rotate.
Miswring between RB unit and
indoor unit.
05-40
Check method
(Error state check method)
Check the capacity of indoor unit
and the pipe diameter.
Check the heat exchanger opera- When a 4-way valves or solenoid
tion capacity at the LED on the valves are faulty, the high pres-
outdoor control PCB (Refer to sure will rise during the cooling
section 5-2). operation and the low pressure
Check the energized state will fall during the heating
(AC220-240V) of the heat ex- operation.
changer 4-way valve and solen- Coil resistance : 1200~1500 .
oid valves.
Check the temperature of the
pipes connecting these valves.
Check the model and model code
of indoor units, liquid piping dia-
meter, pipe length and calculation
for additional charge.(Refer
to section 6-1).
When one of communication
terminal board (Transmission)
terminals 1-2 of the indoor units
is shorted, the resistance
between1 and 2 of communi-
cation terminal board (Transmi-
ssion) of all the indoor units
become zero.
When the number of operating
indoor units was changed,
the discharge temperature of the
indoor units does not become
low or high.
Measure the thermistor Refer to section 7-2-1 to find the
resistance and compare it to correlation between the tempera-
the ambient temperature. ture and thermistor resistance.
When a relevant indoor unit
performs the heating operation,
the high pressure becomes high
and warm air is not discharged
(Trouble occurs especially easily
from the indoor unit.
with the UTF-Y90A4A.)
Remarks
When the diameter is large,
a refrigerant rushing sound is
generated and when
the diameter is small,
capacity will be insufficient.
When gas is insufficient,
the capacity drops and when
gas is excessive, the high
pressure rises abnormally.
Resistance
Short
measurement
circuit
Indoor Indoor
Indoor Indoor
unit
unit unit unit
When the gas insufficiency be-
come seriously, the high
pressure drops and
the discharge temperature
increases abnormally.
When short or open circuit of
thermistor occurred.
Wring between RB unit and in-
door unit must correspond to the
piping connection.