Mitsubishi Electric MXZ-2E53VAHZ, Service Manual

Page: 74 / 328

74
SERVICE FUNCTIONS 10
10-1. 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.
This is to generate heat at the winding.
The compressor uses about 50 W when pre-heat control is turned ON.
Pre-heat control is ON at initial setting.
[How to deactivate pre-heat control]
Turn OFF the power supply for the air conditioner before making the setting.
Set the "4" of SW2 on the outdoor control P.C. board to ON to deactivate pre-heat control function.
Turn ON the power supply for the air conditioner.
NOTE
: Pre-heat control will be turned OFF when the breaker is turned OFF.
Outdoor control P.C. board
SW871
LED
SW1
With this function, you can lock the operation mode of the outdoor unit.
Once the operation mode is locked to either COOL/DRY mode or HEAT mode, the air conditioner
operates in that mode only.
Default setting is required to activate this function.
Please explain about this function to your customers and ask them whether they want to use it.
[How to lock the operation mode]
(1) Turn OFF the power supply and make sure that the LED goes off.
(2) Set SW1 on the outdoor control P.C. board.
(3) Turn ON the power supply.
10-2. LOCKING THE OPERATION MODE OF THE AIR CONDITIONER (COOL, DRY, HEAT) (MXZ-4E83VAHZ)
ON
5 6
SW1
ON
5 6
SW1
Cool/Dry Heat
10-3. LOWERING THE OPERATING NOISE OF THE OUTDOOR UNIT (MXZ-4E83VAHZ)
With this function, you can lower the operating noise of the outdoor unit when the operation load is small,
for example, during night time in COOL mode.
However, note that the cooling and heating capacity can also be lowered if this function is activated.
Default setting is required to activate this function.
Please explain about this function to your customers and ask them whether they want to use it.
[How to lower the operating noise]
(1) Turn OFF the power supply and make sure that the LED goes off.
(2) Set the "5" Switch of SW1 on the outdoor control P.C. board to ON to enable this function.
(3) Turn ON the power supply.
ON
5 6
SW1
MXZ-3E54VA MXZ-3E68VA MXZ-4E72VA
MXZ-4E83VA MXZ-5E102VA MXZ-2E53VAHZ MXZ-4E83VAHZ
OBH723C