28
Check of outdoor thermistors
G
When OPERATION INDICATOR lamp flashes 6-time.
The thermistors in the outdoor unit are abnormal.
Measure the
resistance
between CN641
1
and
2
.
Measure the
resistance
between CN642
1
and
2
.
No
Yes
Replace the
thermistor
except RT64.
In case of RT64,
replace the
inverter P.C.
board.
Since RT64 is
combined with
inverter P.C.
board.
Replace the inverter
P.C. board.
Disconnect the connectors CN641, CN642 and CN643 from the inverter P.C. board.
(Check the characteristics of each thermistor.)
1
Reconnect the
connectors CN641,
CN642 and CN643.
2
Disconnect the
connector between
the compressor and
power transistor
module.
Defrost thermistor RT61
Measure the
resistance
between CN641
3
and
4
.
Turn ON the
power supply and
press the
EMERGENCY
OPERATION
switch.
Discharge
temperature
thermistor RT62
Fin temperature
thermistor RT64
Does the
resistance of the
thermistor have the
characteristics on
page 32?
No
Yes
Does the unit
operate 10 minutes
or more?
Is LED of the
inverter P.C. board
flashes 5 times?
Reconnect the
connector or
connecting wire.
Yes
No
Measure the
resistance
between CN643
1
and
2
.
Ambient
temperature
thermistor RT65
Check of R.V. coil
H
Disconnect connector (CN61) between
compressor and power transistor
module.
Turn ON the power supply and press the
EMERGENCY OPERATION switch
twice (HEAT mode).
Is there 230V AC between CN721
1
and
2
on the power P.C.board 3 minutes after
the power supply is turned ON?
Yes
No
Replace the
power P.C. board.
Replace the 4-way valve.
Disconnect connector (CN61) between
compressor and power transistor
module.
Turn ON the power supply and press the
EMERGENCY OPERATION switch once
(COOL mode).
Is there 230V AC between CN721
1
and
2
on the power P.C.board 3 minutes after
the power supply is turned ON?
No
Yes
Replace the
power P.C. board.
•Defective R.V. coil
•Defective 4-way valve
w
First of all, measure the resistance of R.V. coil to check if the coil is defective (refer to page 25).
w
In case CN721 is not connected or R.V. coil is open, voltage is generated between the
terminal pins of the connector although any signal is not being transmitted to R.V. coil.
Check if CN721 is connected.
CN721
Power P.C. board
(soldered side)
Unit operates COOL mode even if it is set to HEAT mode.
Unit operates HEAT mode even if it is set to COOL mode.
OB328 A--1qxp 04.4.26 4:49 PM Page 28
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