Mitsubishi Electronics SKM28ZD-S Air Conditioner User Manual


 
20
Self diagnosis function
We are constantly trying to do better service to our customers by installing such judges that show abnormality of each function as follows:
Outdoor heat exchanger fluid pipe
sensor error
Outdoor temperature sensor error Broken outdoor sensor wire, poor connector connection
Description of trouble
Room temperature sensor error
Cause
Broken heat exchanger sensor (1) wire, poorconnector
connection
Disconnected sensor
Indoor fan motor error
Heat exchanger sensor (1) error
2 time flash
5 time flash
TIMER lamp ON
1 time flash
RUN lamp
2 time flash
1 time flash
TIMER lamp
RUN lamp keeps flashing
Broken room temperature sensor wire, poor connector connection
Defective fan motor, poor connector connection
Broken heat exchanger fluid pipe sensor wire, poor connector
connection
Characteristics of HEAT mode operation
Mechanism and capacity of HEAT mode operation
Mechanism
The unit draws in heat from the cold outside air, transfers it indoors and heats the room. The heating capacity of the heat pump mechanism decreases
when the outside air temperature gets colder.
The hot air circulation system takes a while before warming up the room temperature.
If the outside temperature becomes extremely low, it would be better to use an additional source of heating.
Defrosting
If the outside temperature becomes low and humidity is high, the heat exchanger in the outdoor unit may frost over, which prevents efficient heating.
If this happens, the automatic defroster is activated and during defrosting the heating operation stops for 5 to 10 minutes.
Both indoor and outdoor fans stop and the RUN light (green) blinks slowly (1.5 sec. ON, 0.5 sec. OFF) during defrosting.
The outdoor unit may give off some steam during defrosting. This is to help the defrosting process and is not a defect.
The HEAT operation resumes as soon as defrosting has been completed.
2 time flash
RUN lamp 2 time flash
Rotor lock
Defective compressor
Open phase on compressor
Defective outdoor unit boards
If heating operation is performed when the outside temperature is high, room temperature may become higher than the set temperature.
Trouble of outdoor unit
Over current
Compressor locking, open phase on compressor output,
shortcircuit on power transformer, closed control valve
Current cut
2 time flash
3 time flash
1 time flash
Over heat of power transistor
Over heat of compressor
4 time flash
5 time flash
RUN lamp ON
Broken power transformer, broken compressor wire
Broken discharge pipe sensor wire, poor connector connection
Compressor blockage
Overload operation, overcharge
Cooling problem
Gas shortage, defective discharge pipe sensor, closed control
valve
6 time flash Error of signal transmission
Defective power supply, Broken signal wire, defective in/outdoor
unit boards
Discharge pipe sensor error Broken discharge pipe sensor wire, poor connector connection
Suction pipe sensor error Broken suction pipe sensor wire, poor connector connection
Broken power transistor sensor wire, poor connector connectionPower transistor sensor error
4 time flash
5 time flash
6 time flash
6 time flash
7 time flash
Heat exchanger sensor (2) error
Broken heat exchanger sensor (2) wire, poor connector
connection
Disconnected sensor
Closed service valve
Heat exchanger sensor (1) error
Closed service valve
Disconnected sensor
RWA012A226_En 03.8.27, 6:48 PM20