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.
Initial 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]
Turn OFF the power supply for the air conditioner before making the setting.
Set SW1 on the outdoor P.C. board as shown in the right figure.
Turn ON the power supply for the air conditioner.
ON ON
COOL/DRY HEAT
SW1 SW1
ON ON
COOL/DRY HEAT
SW1 SW1
ON
ONSW2
1 2 3 4 5 6 ON
SERVICE FUNCTIONS
10
10-1. LOCKING THE OPERATION MODE OF THE AIR CONDITIONER (COOL, DRY, HEAT)
10-2. LOWERING THE OPERATING NOISE OF THE OUTDOOR UNIT
Description of the function:With this function, you can lower the operating noise of the outdoor unit when the operation load is small, for example, during nighttime in COOL mode. However, please note that the
cooling and heating capacity can also be lowered if this function is activated.
Initial 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]
Turn OFF the power supply for the air conditioner before making the setting.
Set the “3” Switch of SW1 on the outdoor P.C. board to ON to enable this function.
Turn ON the power supply for the air conditioner. SW1ON
SW2ON
1 2 3 4 5 6
SW1ON
1 2 3 4
MXZ-3C54/3C68/4C71VA MXZ-4C80/5C100/6C120/6C122VA MXZ-4C80/5C100VA2
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 P.C. board to ON to deactivate pre-heat control function (MXZ-4C80VA, MXZ-4C80VA2, MXZ-5C100VA, MXZ-5C100VA2, MXZ-6C120VA, MXZ-
6C122VA).
Set the “4” of SW1 on the electronic control P.C. board to ON to deactivate pre-heat control function (MXZ-3C54VA, MXZ-3C68VA, MXZ-4C71VA).
Cut the JK wire of the inverter P.C. board to deactivate pre-heat control function (MXZ-2C30VA, MXZ-2C40VA, MXZ-2C52VA).
Turn ON the power supply for the air conditioner.
NOTE: Pre-heat control will be turned OFF when the breaker is turned OFF. MXZ-2C20/2C40/2C52VA
JK
JK
10-3. PRE-HEAT CONTROL
MXZ-2C30VA MXZ-2C40VA MXZ-2C52VA MXZ-3C54VA MXZ-3C68VA MXZ-4C71VA
MXZ-4C80VA MXZ-4C80VA2 MXZ-5C100VA MXZ-5C100VA2 MXZ-6C120VA MXZ-6C122VA
77 OUTDOOR UNIT
INDOOR UNIT A
INDOOR UNIT B
<Incorrect piping>
A B
A B
10-4. AUTO LINE CORRECTING
Outdoor unit has an auto line correcting function which automatically detects and corrects improper wiring or piping.
<MXZ-2C30VA, MXZ-2C40VA, MXZ-2C52VA>
Improper wiring or piping can be automatically detected when one indoor unit is operated in COOL mode for 30 minutes.
When improper wiring or piping is detected, wiring lines are corrected (A to B/ B to A) with the software.
NOTE:
This function may not work due to the condition or environment of the unit, such as the following:
- gas leak, closed stop valve - unit failure such as defective LEV - indoor/outdoor temperature
OUTDOOR UNIT
Refrigerant piping Indoor/outdoor connecting wire
OUTDOOR UNIT
INDOOR UNIT A
INDOOR UNIT A INDOOR UNIT B
INDOOR UNIT B
<Correct line>
<Incorrect wiring>
A B
A B
A B
A B
78
Improper wiring or piping can be automatically detected by pressing the piping/wiring correction switch (SW871).
When improper wiring or piping is detected, wiring lines are corrected.
This will be completed in about 10 to 20 minutes.
[How to activate this function]
1. Check that outside temperature is above 0°C .
(This function does not work when outside temperature is not above 0°C.) 2. Check that the stop valves of the liquid pipe and gas pipe are open.
3. Check that the wiring between indoor and outdoor unit is correct.
(If the wiring is not correct, this function does not work.) 4. Turn ON the power supply and wait at least 1 minute.
5. Press the piping/wiring correction switch (SW871) on the outdoor P.C. board.
Do not touch energized parts.
Make sure that the valves are open and the pipes are not collapsed or clogged.
6. Press the switch to cancel.
NOTE: Indoor unit cannot be operated while this function is activated.
When this function is activated while indoor unit is operating, the operation will be stopped.
Operate indoor unit after the auto line correcting is finished.
Pressing the switch during detection cancels this function.
LED1(Red) Lighted
LED indication during detection:
LED indication after detection:
LED2(Yellow)
Lighted LED3(Green) Once
LED1(Red) Lighted
LED indication after cancel:
LED2(Yellow)
Lighted LED3(Green) Not lighted LED1(Red)
Lighted Blinking
LED2(Yellow) Not lighted
Blinking Other indications
LED3(Green) Lighted
Blinking Completed (Problem corrected/normal) Not completed (Detectin failed)
Refer to "SAFETY PRECAUTIONS WHEN LED FLASHES" located behind the service panel.
Indication
<MXZ-4C80VA, MXZ-4C80VA2, MXZ-5C100VA, MXZ-5C100VA2, MXZ-6C120VA, MXZ-6C122VA>
The record of auto line correcting can be confirmed in the following way:
Press the switch for more than 5 sec.
LED will show the record of auto correcting for about 30 sec. as shown in the table below:
NOTE: Activate this function to confirm the correct wiring after replacing the outdoor P.C. board.
(Previous records are deleted when the outdoor P.C. board is replaced.)
The record cannot be shown if auto line correcting is not canceled (Refer to "How to activate this function").
LED1(Red) 3 timesOnce
LED2(Yellow) 3 timesOnce
LED3(Green) Lighted
Lighted Not corrected Corrected
Number of blinks Wiring line
Turn OFF the power supply.
Turn ON the "4" of SW1 on the display P.C. board.
Turn ON the power supply.
Confirm the correction by the blinking of LED.
Turn OFF the power supply after the confirmation, and turn OFF the "4" of SW1 on the display P.C. board.
Turn ON the power supply.
NOTE: This function does not work when the jumper wire JGO on the inverter P.C. board is cut.
ON
MXZ-2C SW1
LED1 (Red) 3 timesOnce
LED2 (Yellow) 3 timesOnce
Number of blinks Wiring line Not corrected
Corrected
79