Service Functions; Troubleshooting; Change In Defrost Setting; Pre-Heat Control Setting - Mitsubishi SUZ-KA18NA2 Service Manual

9

SERVICE FUNCTIONS

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. TEST POINT DIAGRAM AND VOLTAGE".)
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 (20°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. TEST POINT
DIAGRAM AND VOLTAGE".)
NOTE: When the inverter P.C. board is replaced, check the Jumper wires, and cut/solder them if necessary.
10

TROUBLESHOOTING

10-1. CAUTIONS ON TROUBLESHOOTING
1. Before troubleshooting, check the following
1) Check the power supply voltage.
2) 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.
2) 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.
3) 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.
2) Before servicing check that the connector and terminal are connected properly.
3) 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 "10-2. TROUBLESHOOTING CHECK TABLE" and "10-3. HOW TO PROCEED "SELF-DIAGNOSIS"".
OCH688A
SUZ-KA18NA(H)2 SUZ-KA24/30/36NA(H)2
48°F (9°C)
64°F (18°C)
Lead wiring
15
50°F (10°C)
64°F (18°C)
Housing point