31
Check items
Actions to take
Symptoms
[1]
Check the INV board
error detection circuit.
(unloaded)
[2]
Check the inverter for
damage. (unloaded)
[3]
Check for inverter
damage. (loaded)
[4]
Check the fan motor
for a ground fault and
check the coil for
problems.
1
Overcurrent errors
1
The units stop within 10 seconds
of startup, and a position
detection error or an overcurrent
error is detected.
1
Insulation resistance failure of
the fan motor.
Insulation resistance of below
1 M
Ω
is considered abnormal.
1
An error is detected in less than
30 seconds of startup. (LED2 on
the INV board lights up.)
3
There is no line voltage
imbalance.
An error is detected after 30
seconds of startup (LED2 on the
INV board lights up.), and the
units will stop.
2
Logic error
2
An overcurrent error is detected
after approximately 10 seconds
of operation.
2
Broken fan motor wire
Reference value: Normal
wirewound resistance is several
ohms. (Varies with the
temperature.)
4
A line voltage imbalance
exceeds the greater of the
following after the rotation speed
has been stabilized: 5% or 5V.
3
Overcurrent error due to short-
circuited motor.
2
The line voltage imbalance is 5V
or greater.
3
ACCT sensor circuit fault
4
Position detection error
5
Open-circuited IPM or
disconnected ACCT sensor
1
Turn off the breaker.
*Be sure to turn off the
breaker.
2
Disconnect the connector
CNINV from the INV board.
3
Turn on the breaker.
4
Operate the indoor units.
1
Turn off the breaker.
2
Turn on the breaker.
3
Operate the indoor units.
Disconnect the indoor unit fan
motor wiring, and check the
resistance and the wirewound
resistance of the fan motor.
1
Turn off the breaker.
*Be sure to turn off the
breaker.
2
Disconnect the connector
CNINV from the INV board.
3
Turn SW2-1 on the INV
board to ON.
4
Turn on the breaker.
5
Operate the indoor units.
The units will operate for
approximately 30 seconds
unloaded and then stop. During
the unloaded operation, a
constant line voltage of
approximately 20V will be output.
Replace the INV board.
Replace the INV board.
Replace the INV board.
Replace the fan motor.
Replace the fan motor.
Replace the INV board.
Replace the INV board.
Normal
Normal
*Reconnect the CNINV connector, and set
the SW2 back to its original setting after
checking.
Check to see if the fan motor is locked.
Replace the fan motor if it is locked.
If the problem persists after replacing the
fan motor, replace the INV board.
If the fan motor is not locked, go to item [4].
If no problems were found with item [4],
replace the INV board.
If the problem persists after replacing the
INV board, replace the fan motor.
a) If no problems were found with items [1]
and [2], check for short-circuited motor
wiring.
b) If no problems were found with item a),
replace the fan motor.
c) If the problem persists after replacing the
fan motor, replace the INV board.
a) If a voltage imbalance is detected, go to
item [4].
b) If no problems were found with item [4],
replace the INV board.
c) If the problem persists after replacing the
INV board, replace the fan motor.
a) Replace the INV board.
b) If the problem persists after replacing the
INV board, replace the fan motor.
If the problem described at left happens
when the power is turned on for the first time,
replace the INV board.
*Removing the connector CNINV while the
power is turned on can cause the problem
described at left. Be sure to turn off the
power before disconnecting the connector
CNINV.
(2) Troubleshooting the inverter output-related problems
HWE17030.qxd 17.11.9 16:28 Page 31
