37
<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 (
w
) during compressor operation.
w
RP1.6-2VHA
: 4.15 MPa
RP2.5-6VHA
: 4.41 MPa
RP2.5-6VHA
1
: 4.15 MPa
RP4-6YHA
: 4.15 MPa
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 board
5
Disconnection or contact failure
of 63H connection
6
Defective outdoor controller
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
page 68.)
4
~
6
Put the power off and check F5 is
displayed when the power is put again.
When F5 is displayed, refer to “Judgment
and action” for F5.
7
Check linear expansion valve.
Refer to 11-6.
8
Replace outdoor controller 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
board
5
Defective action of linear
expansion valve
1
Check intake super heat.
Check leakage of refrigerant.
Charge additional refrigerant.
2
Check if stop valve is full open.
34
Put the power off and check if U3 is dis-
played when the power is put again.
When U3 is displayed, refer to “Judgement
and action” for U3.
5
Check linear expansion valve.
Refer to 11-6.
<Abnormalities detected while unit is operating>
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