39
Error Code
Meaning of error code and detection method
Judgment and action
U1
(1302)
Abnormal high pressure (High-pressure
switch 63H operated)
Abnormal if high-pressure switch 63H
operated (more than 4.14 MPa) during
compressor operation.
63H: High-pressure switch
Use current sensor to detect work or
return of 63H.
1
Short cycle of indoor unit
2
Clogged filter of indoor unit
3
Decreased airflow caused by
dirt of indoor fan
4
Dirt of indoor heat exchanger
5
Locked indoor fan motor
6
Malfunction of indoor fan motor
7
Defective operation of stop
valve (Not full open)
8
Clogged or broken pipe
9
Locked outdoor fan motor
0
Malfunction of outdoor fan motor
1
Short cycle of outdoor unit
2
Dirt of outdoor heat exchanger
3
Disconnection or contact failure
of 63H connection
4
Defective outdoor controller
board
5
Defective action of liner expan-
sion valve
6
Refrigerant overcharge
1
-
6
Check indoor unit and repair defectives.
7
Check full open stop valve.
8
Check piping and repair defectives.
9
-
2
Check indoor unit and repair defectives.
3
,
4
Turn the power off and check UH display
when the power is turned on again.
Follow the UH display if UH is displayed.
5
Check linear expansion valve.
Refer to 11-6.
6
Replace refrigerant.
U1
Abnormal low current or open phase
• An extreme degradation of current value
causes abnormal stop.
• Abnormal if current detected phase
(V-phase) is open phase after first com-
pressor start-up after supplying the power
by three phase power supply model.
• When compressor is operating, compres-
sor is suspended under the following
condition: and when current detector (CT)
detects a current, which is lower than the
detected current specified in the table
below, under the following condition:
<Condition>
1
For PU/PUH-P71~P100V
Current detector (CT) has detected a
current, which is lower than the detected
current specified in the table below, for
0.7-0.8 second.
2
For PU/PUH-P71 ~ P140Y
Current detector (CT) has detected a
current, which is lower than the detected
current specified in the table below, for
0.4-0.5 second.
1
Shortage of refrigerant
2
Abnormal pressure degrada-
tion by pump down operation
3
V-phased open phase of com-
pressor
4
Abnormal compressor
Not abnormal if V is instantly
displayed when the main
power is off.
1
Check if refrigerant pressure is not degraded.
2
Check current of compressor operation when
abnormality occurred.
3
Check wiring of compressor.
4
Check or replace compressor.
Case
Model
P71V
P71Y,P100V,P100Y
P125Y
P140Y
Detected current
2.4 A
1.0 A
1.2 A
1.6 A
U2
(1102)
Abnormal high discharging (compressor
surface) temperature
Abnormal if discharging (compressor
surface)
temperature thermistor (TH4)
exceeds following temperature during com-
pressor operation.
Normal operation: 115
:
(P71-P100)/
125
:
(P125,P140)
or more for 3 minutes
continuously or 135
:
During defrosting: 135
:
1
Over-heated compressor
operation caused by shortage
of refrigerant
2
Defective operation of stop
valve
3
Defective thermistor
4
Defective outdoor controller
board
5
Defective action of linear
expansion valve
1
Check intake super heat.
Check leakage of refrigerant.
Charge
refrigerant.
2
Check if stop valve is full open.
34
Turn the power off and check if U3 is
displayed when the power is turned on
again.
When U3 is displayed, refer to “Judgement
and action” for U3.
5
Check linear expansion valve.
Refer to 11-6.
U2
(1501)
Abnormal shortage of refrigerant
Abnormal if intake super heat exceeds
following temperature during heating com-
pressor operation.
70
:
or more, and indoor pipe <condenser-
evaporator> temperature (TH5) is 35
:
or
less.
1
Leakage or shortage of refrig-
erant
2
Defective operation of stop
valve (not full open)
3
Defective thermistor (TH4,
TH5, TH6)
4
Defective outdoor controller
board
5
Defective action of electric
expansion valve
1
Check leakage of refrigerant.
Charge
refrigerant.
2
Check if stop valve is full open.
34
Turn the power off and check if U3 or U4 is
displayed when the power is put again.
When U3 or U4 is displayed, refer to
“Judgement and action” for U3 or U4.
6
Check linear expansion valve.
Refer to 11-6
OC379F
