Service Function; Troubleshooting - Mitsubishi Electric SUZ-KA09NA Service Manual

9
SERVICE FUNCTIONS
SUZ-KA09NA
9-1. CHANGE IN DEFROST SETTING
Changing defrost finish temperature
<JS> To change the defrost finish temperature, cut/solder the JS wire of the outdoor inverter P.C. board.
(Refer to 10-6-1.)
Jumper
Soldered
(Initial setting)
JS
None
(Cut)
9-2. PRE-HEAT CONTROL SETTING
PRE-HEAT CONTROL
When moisture gets into the refrigerant cycle, it may interfere the start-up of the compressor at low outside temperature.
The pre-heat control prevents this interference. The pre-heat control turns ON when outside temperature is 68°F (0°C)
or below. When pre-heat control is turned ON, compressor is energized. (About 50 W)
<JK> To activate the pre-heat control, cut the JK wire of the inverter P.C. board. (Refer to 10-6.1)
NOTE: When the inverter P.C. board is replaced, check the Jumper wires, and cut/solder them if necessary.
10

TROUBLESHOOTING

SUZ-KA09NA
10-1. CAUTIONS ON TROUBLESHOOTING
1. Before troubleshooting, check the following
1) Check the power supply voltage.
) Check the indoor/outdoor connecting wire for miswiring.
2. Take care of the following during servicing
1) Before servicing the air conditioner, be sure to turn OFF the main unit first with the remote controller, and turn off the
breaker.
) Be sure to turn OFF the power supply before removing the front panel, the cabinet, the top panel, and the electronic
control P.C. board.
) When removing the electrical parts, be careful of the residual voltage of smoothing capacitor.
4) When removing the electronic control P.C. board, hold the edge of the board with care NOT to apply stress on the
components.
5) When connecting or disconnecting the connectors, hold the housing of the connector. DO NOT pull the lead wires.
3. Troubleshooting procedure
1) First, check if the OPERATION INDICATOR lamp is blinking ON and OFF to indicate an abnormality.
) Before servicing check that the connector and terminal are connected properly.
) When the electronic control P.C. board seems to be defective, check the copper foil pattern for disconnection and the
components for bursting and discoloration.
4) Refer to 10-. and 10-.
SUZ-KA12NA
Defrost finish temperature
SUZ-KA09/12/15
41°F (5°C)
50°F (10°C)
SUZ-KA12NA
Lead wiring
SUZ-KA15NA
SUZ-KA18
48°F (9°C)
64°F (18°C)
SUZ-KA15NA
Housing point
14
SUZ-KA18NA
SUZ-KA18NA