Mitsubishi Electric MXZ-2D33VA Service Manual page 122

10-5. PRE-HEAT CONTROL
If moisture gets into the refrigerant cycle, or when refrigerant is liquefied and collected in the compressor,
it may interfere the start-up of the compressor. To improve start-up condition, the compressor is energized even while it is
not operating to generate heat at the winding.
The compressor uses about 50 W when pre-heat control is turned ON. Pre-heat control is OFF(MXZ-2D33VA/2D40VA/2
D42VA/2D42VA2/2D53VA/2D53VA2/2D53VAH/2D53VAH2)/ON (MXZ-3D54VA/3D54VA2/3D68VA/4D72VA/4D83VA/5D1
02VA/6D122VA) at the default setting.
[How to activate pre-heat control]
MXZ-2D33VA/2D40VA/2D42VA/2D42VA2/2D53VA/2D53VA2/2D53VAH/2D53VAH2/3D54VA/3D54VA2/3D68VA/4D72VA/
4D83VA/5D102VA
(1) Turn OFF the power supply and make sure that the LED goes off.
(2) Set the "4" of SW2 as shown figure below to ON to activate pre-heat control function.
(3) Turn ON the power supply.
MXZ-2D33VA/2D40VA/2D42VA/2D42VA2
MXZ-2D53VA/2D53VA2/2D53VAH/2D53VAH2
SW2 on the outdoor display P.C. board
MXZ-3D54VA/3D54VA2/3D68VA/4D72VA
MXZ-4D83VA/5D102VA
SW2 on the outdoor control P.C. board
SW2
MXZ-6D122VA
(1) Turn OFF the power supply for the air conditioner before making the setting.
(2) Set the "4" of SW2 as shown figure below to OFF to activate pre-heat control function.
(3) Turn ON the power supply for the air conditioner.
MXZ-6D122VA
SW2 on the outdoor control P.C. board
SW2
NOTE: Pre-heat control will be turned OFF when the power supply is turned OFF.
OBH626K
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