Mitsubishi Heavy Industries SCM71ZS-W User Manual

-
152
-
'19 • SCM-SM-276
Error code
Remote control:
LED Green Red
Indoor
Outdoor
Content
E57
Insufcient refrigerant amount
or detection of service valve closure
Keeps ashing
Stays OFF
– 2
-
time ash
1. Applicable model
5. Troubleshooting
All models
Diagnosis Countermeasure
NO
YES
NO
YES
Is the
service valve fully
opened?
Are the
connections of indoor
heat exchanger and/or return air
temperature sensor
connectors OK?
NO
YES
NO
YES
Are the
characteristics of indoor heat
exchanger and/or return air
temperature sensor
OK?
Is the low
pressure during operation
normal?
Indoor heat exchanger, return air temperature sensor
Temperature-resistance characteristics
15
10
5
010304020 50
Temperature
sensor
resistance (kΩ)
Temperature (°C)
5kΩ at 25°C
(Broken wire)
(Short-circuit)
Open fully.
Correct indoor heat
exchanger, return air
temperature sensor
connector connections.
Defective indoor heat
exchanger, return air
temperature sensor
➞
Replace.
Charge refrigerant.
Defective indoor unit
control PCB
➞
Replace.
(Defective indoor heat
exchanger, return air
temperature sensor input
circuits)
2. Error detection method
• Judge insufficient refrigerant
amount by detecting the
temperature differnce between
indoor heat exchanger (Thi-R)
and indoor return air (Thi-A).
3 . Condition of error displayed
When the insufcient refrigerant
amount is detected 3 times
within 60 minutes.
4. Presumable cause
• Defective indoor heat
exchanger temperature sensor
• Defective indoor return air
temperature sensor
• Defective indoor unit control
PCB
• Insufficient refrigerant amount
Note: When the compressor speed is 60 rps or under at 5 minutes after the start of compressor or the completion of defrost operation, the low refrigerant protection
control judges, by detecting the difference between the indoor heat exchanger temperature (Thi-R) and the indoor return air temperature (Thi-A), that it is in the
state of gas leakage, and stops the compressor.
Cooling: Indoor return air temperature (Thi-A) – Indoor heat exchanger temperature (Thi-R)
＜ ＿ 4℃
Heating: Indoor heat exchanger temperature (Thi-R) – Indoor return air temperature (Thi-A) ＜ ＿ 6℃

Mitsubishi Heavy Industries SCM71ZS-W Specifications

General

Brand	Mitsubishi Heavy Industries
Model	SCM71ZS-W
Category	Air Conditioner
Language	English