High - Mitsubishi Electric PSA-RP100KA Service Manual

9-2. SELF-DIAGNOSIS ACTION TABLE
Abnormal point and detection method
Error Code
Room temperature thermistor (TH1)
1 The unit is in 3-minute resume
prevention mode if short/open of
thermistor is detected. Abnormal if the
unit does not reset normally after 3
minutes. (The unit returns to normal
operation, if it has been reset normally.)
2 Constantly detected during cooling,
drying, and heating operation.
Short: -90: or more
Open: -40: or less
P1
Pipe temperature thermistor/Liquid
(TH2)
1 The unit is in 3-minute resume
prevention mode if short/open of
thermistor is detected. Abnormal if the
unit does not reset normally after 3
minutes. (The unit returns to normal
operation, if it has been reset normally.)
2 Constantly detected during cooling,
P2
drying, and heating (except defrosting)
operation
Short: 90: or more
Open: -40: or less
Freezing/overheating protection is
operating
1 Freezing protection (Cooling mode)
The unit is in 6-minute resume
prevention mode if pipe <liquid or
condenser/evaporator> temperature
stays under -15: for 3 minutes, 3
minutes after the compressor started.
Abnormal if it stays under -15: for 3
minutes again within 16 minutes after
6-minute resume prevention mode.
2 Overheating protection (Heating mode)
The units is in 6 minute resume
P6 prevention mode if pipe <condenser /
evaporator> temperature is detected as
over 70: after the compressor started.
Abnormal if the temperature of over
70: is detected again within 30 minutes
after 6 minute resume prevention mode.
OCH528
Note: Refer to the manual of outdoor unit for the details of display
such as F, U, and other E.
Cause
1 Defective thermistor
characteristics
2 Contact failure of connector
(CN20) on the indoor controller
board (Insert failure)
3 Breaking of wire or contact
failure of thermistor wiring
4 Defective indoor controller
board
1 Defective thermistor
characteristics
2 Contact failure of connector
(CN44) on the indoor controller
board (Insert failure)
3 Breaking of wire or contact
failure of thermistor wiring
4 Defective refrigerant circuit
is causing thermistor
temperature of 90: or more
or -40: or less.
5 Defective indoor controller
board
(Cooling or drying mode)
1 Clogged filter (reduced airflow)
2 Short cycle of air path
3 Low-load (low temperature)
operation out of the tolerance
range
4 Defective indoor fan motor
• Fan motor is defective.
• Indoor controller board is
defective.
5 Defective outdoor fan control
6 Overcharge of refrigerant
7 Defective refrigerant circuit
(clogs)
(Heating mode)
1 Clogged filter (reduced airflow)
2 Short cycle of air path
3 Over-load (high temperature)
operation out of the tolerance
range
4 Defective indoor fan motor
• Fan motor is defective.
• Indoor controller board is
defective.
5 Defective outdoor fan control
6 Overcharge of refrigerant
7 Defective refrigerant circuit
(clogs)
8 Bypass circuit of outdoor unit
is defective.
14
Countermeasure
1–3 Check resistance value of thermistor.
0: .... 15.0k"
10: .... 9.6k"
20: .... 6.3k"
30: .... 4.3k"
40: .... 3.0k"
If you put force on (draw or bend) the lead wire
with measuring resistance value of thermistor,
breaking of wire or contact failure can be
detected.
2 Check contact failure of connector (CN20)
on the indoor controller board. Refer to 9-6.
Turn the power on again and check restart
after inserting connector again.
4 Check room temperature display on remote
controller.
Replace indoor controller board if there
is abnormal difference with actual room
temperature.
Turn the power off, and on again to operate
after check.
1–3 Check resistance value of thermistor.
For characteristics, refer to (P1) above.
2 Check contact failure of connector (CN44)
on the indoor controller board. Refer to 9-6.
Turn the power on and check restart after
inserting connector again.
4 Check pipe <liquid> temperature with remote
controller in test run mode. If pipe <liquid>
temperature is extremely low (in cooling
mode) or high (in heating mode), refrigerant
circuit may have defective.
5 Check pipe <liquid> temperature with
remote controller in test run mode. If there is
extremely difference with actual pipe <liquid>
temperature, replace indoor controller board.
Turn the power off, and on again to operate
after check.
(Cooling or drying mode)
1 Check clogs of the filter.
2 Remove blockage.
4 Refer to 9-6.
5 Check outdoor fan motor.
67 Check operating condition of refrigerant
circuit.
(Heating mode)
1 Check clogs of the filter.
2 Remove blockage.
4 Refer to 9-6.
5 Check outdoor fan motor.
6~8Check operating condition of refrigerant
circuit.