30
<Abnormalities detected while unit is operating>
Error Code Meaning of error code and detection method
Judgment and action
U1
(1302)
Abnormal high pressure (High-pressure
switch 63H worked)
Abnormal if high-pressure switch 63H
worked ( 3.6MPa ) during compressor
operation.
63H: High-pressure switch
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
Decreased airflow caused by
defective inspection of outside
temperature thermistor
(It detects lower temperature
than actual temperature.)
4
Disconnection or contact failure
of connector (63H) on outdoor
controller circuit board
5
Disconnection or contact failure
of 63H connection
6
Defective outdoor controller cir-
cuit board
7
Defective action of linear
expansion valve
8
Malfunction of fan driving
circuit
1
~
6
Check indoor unit and repair defectives.
7
Check if stop valve is full open.
8
Check piping and repair defectives.
9
~
2
Check outdoor unit and repair defectives.
3
Check the inspected temperature of outside
temperature thermistor on LED display.
(SW2 on A-Control Service Tool : Refer to 12-10.)
4
~
6
Turn the power supply off and check F5 is
displayed when the power supply is
turned again. When F5 is displayed, refer
to “Judgment and action” for F5.
7
Check linear expansion valve.
Refer to 12-6.
8
Replace outdoor controller circuit board or
FAN controller circuit board.
Case
U2
(1102)
Abnormal high discharging temperature
(1) Abnormal if discharge temperature
thermistor (TH4) exceeds 125
:
or
110
:
continuously for 5 minutes.
Abnormal if condenser/evaporator
temperature thermistor (TH5) exceeds
40
:
during defrosting and discharge
temperature thermistor (TH4) exceeds
110
:
.
(2) Abnormal if discharge super heat
(Cooling: TH4 – TH5 / Heating: TH4 –
TH6) increases.
All the conditions in A or B are detected
simultaneously for 10 minutes
continuously after 6 minutes past from
compressor start-up (including the
thermostat indication or recovery from
defrosting).
<Condition A>
• Heating mode
• When discharge super heat is less
than 70 deg.
• When the TH6 temp is more than the
value obtained by TH7 – 5 deg.
• When the condensing temp of TH5 is
less than 35
:
.
<Condition B>
• During comp operation (Cooling and
Heating)
• When discharge super heat is less
than 80 deg in Cooling.
• When discharge super heat is less
than 90 deg in Heating.
• When condensing temp of TH6 is
more than –40
:
. (In Cooling only.)
1
Over-heated compressor oper-
ation caused by shortage of
refrigerant
2
Defective operation of stop
valve
3
Defective thermistor
4
Defective outdoor controller cir-
cuit board
5
Defective action of linear
expansion valvep
1
Check intake super heat.
Check leakage of refrigerant.
Charge additional refrigerant.
2
Check if stop valve is full open.
34
Turn the power supply off and check if U3
is displayed when the power supply is
turned again. When U3 is displayed, refer
to “Judgement and action” for U3.
5
Check linear expansion valve.
Refer to 12-6.
<Abnormalities detected while unit is operating>
OC338C-1.qxp 07.5.24 11:31 AM Page 30
