Block distinction
Operation of diagnosis function
Check
code
Block
Check
code
Cause of operation
Air
conditioner
status
Display flashing
error
Serial signal
1) Defective wiring of the
Indoor unit
Flashes when
1) to 3) The outdoor unit never
and connecting
connecting cable or
operates
error is detected.
operate.
cable.
miss-wiring.
continue.
Flashing stop
Check connecting cable and correct
2) Operation signal has not
Outdoor unit and outdoor unit
if defective wiring.
send from the indoor unit
stop.
start to operate
Check 25A fuse of inverter P.C. board.
when operation start.
when the return
Check 3.15A fuse of inverter
3) Outdoor unit has not
signal from the
P.C. board.
send return signal to the
outdoor unit is
Check operation signal of the indoor
indoor unit when operation
normal.
unit by using diode. Measure voltage
started.
at terminal block of the indoor unit
4) Return signal from the
between No.2 and No.3 (or L2 and S)
outdoor unit is stop during
If signal is varied 15-60V continuously,
operation.
replace inverter P.C. board.
Some protector
If signal is not varied, replace indoor
(hardware, if exist) of the
P.C. board.
outdoor unit open
4) The outdoor unit abnormal stop at
circuit of signal.
some time.
Signal circuit of indoor
If the other check codes are found
P.C. board or outdoor
concurrently, check them together.
P.C. board is failure
Check protector (hardware) such
in some period.
as Hi-Pressure switch,
Thermal-Relay, etc.
Check refrigerant amount or any
possibility case which may caused
high temperature or high pressure.
Check operation signal of the indoor
unit by using diode. Measure voltage
at terminal block of the indoor unit
between No.2 and No.3 (or L2 and S)
If signal is varied 15-60V continuously,
replace inverter P.C. board.
If signal is not varied, replace indoor
P.C. board.
Action and Judgment
* Signal send only 1 minute and stop. Because of return signal from outdoor unit has not received.
** Signal resend again after 3 minutes stop. And the signal will send continuously.
** * 1 minute after resending, the indoor unit display flashes error.
VDC
Time (Min)
0
3
4
7
8
15
60
M
e
a
s
u
re
d
s
ig
n
a
l
v
o
lt
a
ge
by
a
pply
di
o
de
3 minutes Delay, start
counting from power
supply ON or remote
OFF.
3 minutes stop
*
**
***
Sending signal of the indoor unit when have not return
signal from the outdoor unit.
Voltage variation stop
or have not voltage
output.
Note :
Operation signal of the indoor unit shall be measured in the sending period as
picture below.
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