33
SERVICE FUNCTIONS
9
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
Defrost fi nish temperature
MUZ-HM09/12
-
U1
MUZ-HM09
-
U8
MUZ-HM12
-
U8
MUZ-HM15/18
MUZ-HM24
JS
Soldered
(Initial setting)
52°F (11°C)
41°F (5°C)
50°F (10°C)
41°F (5°C)
50°F (10°C)
None
(Cut)
52°F (11°C)
46°F (8°C)
55°F (13°C)
50°F (10°C)
64°F (18°C)
9-2. PRE-HEAT CONTROL SETTING
When moisture gets into the refrigerant cycle, it may interfere with the start-up of the compressor at low outside tempera-
ture. The pre-heat control prevents this interference. The pre-heat control turns ON when the discharge temperature ther-
mistor is 68°F (20°C) or below. When the pre-heat control turns ON, the compressor is energized. (About 50 W)
Pre-heat control setting
<JK>
ON: To activate the pre-heat control, cut JK wire of the inverter P.C. board.
OFF: To deactivate the pre-heat control, solder JK wire of the inverter P.C. board.
(Refer to 10-6.1)
Jumper
Pre-heat control setting
JK
Soldered
Deactivated
(Factory setting)
Cut
Activated
NOTE:
When the inverter P.C. board is replaced, check the jumper wires, and cut/solder them if necessary.
MUZ-HM09NA MUZ-HM09NA2 MUZ-HM12NA MUZ-HM12NA2
MUZ-HM15NA MUZ-HM15NA2 MUZ-HM18NA MUZ-HM18NA2
MUZ-HM24NA MUZ-HM24NA2
OBH747C
