37
Abnormal points and detection method
Judgment and action
U1
(1302)
High pressure (High-pressure switch
63H operated)
Abnormal if high-pressure switch 63H
operated (
*
) during compressor operation.
* 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 fully 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 defect.
7
Check if stop valve is fully open.
8
Check piping and repair defect.
9
–
2
Check outdoor unit and repair defect.
3
Check the inspected temperature of outside
temperature thermistor on LED display.
(SW2 on A-Control Service Tool : Refer
to
"10-10. FUNCTION OF SWITCHES,
CONNECTORS AND JUMPERS".)
4
–
6
Turn the power off and check F5 is
displayed when the power is turned again.
When F5 is displayed, refer to “Judgment
and action” for F5.
7
Check linear expansion valve.
Refer to "10-6. HOW TO CHECK THE PARTS".
8
Replace outdoor controller board.
Case
U2
(1102)
High discharging temperature
(1) Abnormal if discharge temperature
thermistor (TH32) exceeds 125
:
or
110
:
continuously for 5 minutes.
Abnormal if condenser/evaporator
temperature thermistor (TH5) exceeds
40
:
during defrosting and discharge
temperature thermistor (TH32) exceeds
110
:
.
(2) Abnormal if discharge super heat
(Cooling: TH32−H5 /
Heating: TH32−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
:
.
• When the TH6 temp is more than the
value obtained by TH7−5
:
.
• 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
:
in Cooling.
• When discharge super heat is less
than 90
:
in Heating.
• When condensing temp of TH6 is
more than −40
:
. (In Cooling only.)
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 additional 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 "10-6. HOW TO CHECK THE PARTS".
<Abnormalities detected while unit is operating>
Check code
OCH566A
