Mitsubishi Electric PSA Series, Руководство по обслуживанию

Страница: 18 / 58

18 19
OCH724
9-3. SELF-DIAGNOSIS ACTION TABLE
Note: Refer to the manual of outdoor unit for the
details of display such as F, U, and other E.
Check Code
Abnormal point and detection method
Cause
Countermeasure
P1
P2
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°C or more
Open: −40°C or less
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
–
3
Check resistance value of thermistor.
0°C.... 15.0 kΩ
10°C.... 9.6 kΩ
20°C.... 6.3 kΩ
30°C.... 4.3 kΩ
40°C.... 3.0 kΩ
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.
TEST POINT DIAGRAM". 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.
No abnormality when above countermesures
have no problems.
Turn the power off, and on again to operate
after check.
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,
drying, and heating (except defrosting)
operation
Short: 90°C or more
Open: −40°C or less
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°C or more or −40°C or
less.
5
Defective indoor controller
board
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.
TEST POINT DIAGRAM ". 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 be 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.
No abnormality when above countermesures
have no problems.
Turn the power off, and on again to operate
after check.
P6
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°C for 3 minutes, 3
minutes after the compressor started.
Abnormal if it stays under − 15°C 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
prevention mode if pipe <condenser/
evaporator> temperature is detected as
over 70°C after the compressor started.
Abnormal if the temperature of over
70°C is detected again within 30 minutes
after 6-minute resume prevention mode.
(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
Overload (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.
(Cooling or drying mode)
1
Check clogs of the filter.
2
Remove blockage.
4
Refer to "9-5. HOW TO CHECK THE
PARTS".
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 "9-5. HOW TO CHECK THE
PARTS".
5
Check outdoor fan motor.
6
–
8
Check operating condition of refrigerant
circuit.