Troubleshooting (No Error Code) - Fujitsu AB12 Service Manual

Troubleshooting (No error code)

8-4-1
How to read the tables
1.Select the relevant item errors 1 to 5 below,and decide the table to be used.
2.Deduce "Cause" from "LED display" and "Symptom that can occur other than title".
3.Check if the deduced "Cause" is correct by means of "Check" and "Remarks".
When there is no error code display at the indoor unit ,outdoor unit or centralized remote controller,
but there is one of the following operation errors,check the cause in the following order:
1.Indoor fan does not operate normally
2.System does not cool or heat
1. Indoor unit fan does not operate normally
LED display
Indoor Outdoor Remote
unit unit controller
Body PCB LED
LCD
LED 1 to 6
No display Error No display
display
(Transmission
line error)
Normal after the power reset.
Error Error Normal
display display display
(Remote (Indoor-unit
or
controller
error)
no display
communi-
cation system
error)
Normal after the power reset.
Normal Normal Normal
display display display
or
no display
Normal
Normal Normal
display
display display
3.Indoor unit makes an abnormal sound
4.Water leaking from indoor unit
5.Others
Symptom that
can occur other
Cause
than title
Power not supplied to indoor unit
Circuit breaker OFF
Power line faulty
Indoor unit leakage
(short circuit).
(Circuit to which voltage is
applied when energized is
leaking electricity.)
Indoor unit leaking
(short circuit).
(Circuit to which voltage is
applied only during operation is
leaking electricity.)
Communication faulty between
indoor unit and remote controller
(wired).
Open circuit.
Remote control group control
interior communication line faulty.
Open circuit
Communication line faulty
between indoor unit and remote
controller(wired)
Erroneous connection
(polarity incorrect)
Remote control group control
interior communication line faulty.
Erroneous connection
(Polarity incorrect)
Remote controller master/slave
setting switch (DIP SW 1-4)
setting incorrect.
Capacity of indoor fan
capacitor faulty.
Thermo-control
Cold air blow prevention control
in progress(heating operation)
Cool/heat switching
control in progress
(heat recovery type)
– 114 –
Check method
(Error state check method)
Check the voltage across indoor
unit power supply terminal
board (Power Supply) terminals
1-2.
Drop the indoor unit power supply
terminal board (Power Supply1,2)
and indoor unit metal part
resistance value to near zero by
opening the circuit breaker
immediately after setting the
indoor unit circuit breaker to ON.
When the indoor unit circuit
breaker trips during operation,
locate the faulty indoor unit by
disconnecting the PCBs one by
one (disconnect CN1).
Then check the individual
electric parts for leakage.
When 1-2, 2-3, and 3-1 at the
indoor unit terminal board
(Remote Control) are shorted,
the resistance across red-white,
white-black, and black-red
does not indicate a value near
zero.
Check the wiring color and wiring
connection of indoor unit terminal
board(Remote Control)
terminals 1,2, and 3.
When terminals 1-2, 2-3, and 3-1
at the indoor unit terminal board
(Remote Control) are shorted,
the resistance across red-white,
white-black, and black-red at the
remote control terminals does
not indicate a value near zero.
Check the wiring color and wiring
connection of indoor unit terminal
board(Remote Control)
terminals 1,2, and 3.
When indoor unit operated for
each remote control group,
operation is abnormal.
Check the indoor unit Model No.
and capacity of the capacitor.
Set temperature is set to near
room temperature and louver
operation signal is not received.
Area (heat exchanger) near
indoor unit outlet is not warm
and up-down louvers are set to
horizontal position.
At least 3 minutes did not elapse
after switching from cooling to
heating or from heating to
cooling.
Remarks
Voltage across 1-2: 220~240V
When shorted,the resistance
across indoor unit power supply
terminal board(Power Supply)
terminals 1-2 approaches zero.
If short-circuited,the resistance
across the electric parts will
indicate a value near zero.
Wiring color and indoor unit
terminal board(Remote Control)
combinations are red-1,white-2,
and black-3.
Wiring color and indoor unit
terminal board(Remote Control)
combinations are red-1,white-2,
and black-3.
Does not operate when there
is no master unit
(SW 1-4 set to OFF) in one
remote control group.
Indoor fan operates a little every
five minutes during thermo-
control.
Wait several minutes,
then restart the heating
operation.
When the operating state was
switched from cool to heat,
heat to cool ,or stop to heat,
it takes 3 minutes to balance the
refrigerant pressure in the
RB unit.