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HWE10170 GB
3. Troubleshooting when the main power breaker trips
Check items Symptoms Actions to take
[3]
Check for
inverter
damage.
(loaded)
(1) Turn off the breaker. 1) The units stop within 10 sec-
onds of startup, and a posi-
tion detection error or an
overcurrent error is detect-
ed.
Error code:4255
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.
(2) Turn on the breaker. 2) An overcurrent error is de-
tected after approximately
10 seconds of operation.
Error code:4255
a)Replace the INV board.
b)If the problem persists after replacing
the INV board, replace the fan motor.
(3) Operate the indoor
units.
3) Overcurrent error due to
short-circuited motor
Error code:4255
a)If no problems were found with items
[1] and [2], check for short-circuited mo-
tor 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.
4) A line voltage imbalance ex-
ceeds the greater of the fol-
lowing after the rotation
speed has been stabilized:
5% or 5V.
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.
[4]
Check the
fan motor
for a ground
fault and
check the
coil for
problems.
Disconnect the indoor unit fan
motor wiring, and check the
resistance and the wire-
wound resistance of the fan
motor.
1) Insulation resistance failure
of the fan motor
Insulation resistance of be-
low 1 M Ω is considered ab-
normal.
Replace the fan motor.
2) Broken fan motor wire
Reference value: Normal
wirewound resistance is
several ohms.
(Varies with the tempera-
ture)
Replace the fan motor.
Check items Symptoms Actions to take
[1] Check the resistance between the
terminals of power supply terminal
block TB2 with an ohmmeter.
1) 0 to several ohms, or insula-
tion resistance failure
Check the components in the main invert-
er circuit.
*Refer to "4. Simple check on the main in-
verter circuit components".(page 50)
a) Diode bridge
b) Inrush current limiting resistor
c) AC reactor (ACL)
d) Current sensor (ACCT)
[2] Turn the power back on and check
again.
1) Main power breaker is tripped.
2) Nothing appears on the re-
mote controller.
[3] Check the indoor unit for normal
operation.
1) The indoor unit operates nor-
mally without tripping the main
breaker.
a) Look for a possible short-circuit, and if
found, repair.
b) If no problems are found with item "a)"
there may be problems with the fan
motor.
2) Main power breaker is tripped. The fan motor may have had a ground
fault. See section 2.-[1].
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