Is there voltage 230 VAC between the indoor terminal
block S1 and S2? No
Yes
Replace the indoor electronic control P.C.
board.
Rectify indoor/outdoor connecting wire.
Yes If lights up, OK.
If fl ashes, refer to 11-3.
Does the left lamp of OPERATION INDICATOR lamp on the indoor unit light up?
Dose LED on the inverter P.C.
board light up or fl ash? (Refer
to 11-6.1.) No
Replace the inverter P.C. board.
Is there voltage 260 - 370 VDC between DB61 (+) and DB61 (–) on the inverter P.C. board?
(Refer to 11-6.1.) No
Check the electric parts in main circuit.
Yes
Yes No Disconnect the connector between compressor and power module.
Turn ON power supply and press EMERGENCY OPERATION switch.
Inverter P.C. board (Solder side)
DB61
260 - 370 VDC
44 Press OPERATE/STOP (ON/OFF) button of the remote
controller (the set temperature is displayed) with the remote controller headed towards the indoor unit. 1 Expansion valve operates in full-opening direction.
OK
NOTE: After check of LEV, do the undermentioned operations.
1. Turn OFF the power supply and turn it ON again.
2. Press RESET button on the remote controller.
1. Regardless of normal or abnormal condition, a short beep is emitted once the signal is received.
Measure each voltage between connector pins of CN724 on the inverter P.C. board.
1. Pin (-) — Pin (+) 2. Pin (-) — Pin (+) 3. Pin (-) — Pin (+) 4. Pin (-) — Pin (+)
Is there about 3 - 5 VAC between each?
NOTE: Measure the voltage by an analog tester.
Properly fi x the LEV coil to the expansion valve.
Replace the inverter P.C.
board.
Replace the LEV coil.
Replace the expansion valve.
Is LEV coil properly fi xed to the expansion valve?
Does the resistance of LEV coil have the characteristics?
(Refer to 11-4.)
Do you hear the expansion valve "click, click···"?
Do you feel the expansion valve vibrate when touching it ?
Turn ON the power supply.
<Preparation of the remote controller>
While pressing both OPERATION SELECT button and TEMP button on the remote controller at the same time, press RESET button.
First, release RESET button.
Hold down the other 2 buttons for another 3 seconds.
Make sure that the indicators on the LCD screen shown in the right fi gure are all displayed.
Then release the buttons.
Yes No
No
Yes No Yes
No
Yes
K Check of LEV (Expansion valve)
Check the outdoor fan motor.
(Refer to 11-5. .)
Is the fuse (F901) blown on the in- verter P.C. board?
Check the connection of the connectors (CN931, CN932) of the outdoor fan motor.
If the connection is poor, make it correct.
Operate the outdoor unit by starting EMERGENCY OPERATION.
Check the LED indication on the in- verter P.C. board.
Does the LED fl ash 10 times?
Replace the inverter P.C. board.
Check the corresponding parts following LED indication.
(Refer to 11-3.) Yes
No
Yes
(10-time fl ash)
No
L Check of inverter P.C. board
46
M How to check miswiring and serial signal error
• Turn OFF inverter-controlled lighting equipment.
• Turn OFF the power supply and then turn ON again.
• Press EMERGENCY OPERATION switch.
A
Is serial signal error indicated 6 minutes later?
B Yes
• Reinstall either the unit or the light away from each other.
• Attach a fi lter on remote control receiving section of the indoor unit.
No Turn the main power supply
OFF.
Is there rated voltage in the power supply?
Yes No
Check for incorrect indoor-outdoor connecting wiring.
Check the power supply.
A
Is there rated voltage between outdoor terminal block S1 and S2?
No Yes
Check for miswiring, broken wires, and loose wire connection between the main power supply and outdoor terminal block S1 and between the main power supply and outdoor terminal block S2.
Wait for 2 or more minutes after the main power supply is turned on.
Touch S2 and S3 with tester probes and start the emergency operation.
When the emergency operation starts, does the rated voltage occur for 2 seconds between indoor terminal block S2 and S3?
Yes Turn the main power supply
OFF.
Turn the main power supply ON.
Wait for 2 or more minutes after the main power sup- ply is turned ON. Touch CN202 and JPG with tester probes and start the emergency operation.
During the emergency operation, does DC (2V or more) occur for 2 seconds between CN202 and JPG on the indoor electronic control P.C. board?
No
Does the indoor OPERATION INDICATOR lamp (left) blink continuously 6 minutes after the emergency operation starts?
No Does the outdoor LED light up?
Replace the indoor electronic control P.C. board.
Replace the indoor power P.C.
board.
Yes Yes
Does the outdoor LED blink 6 times?
Yes
Confi rm that the thermostat is OFF and wiring is not loose.
No
Does DC (6V or more) occur between indoor terminal block S2 and S3?
Yes
Replace the outdoor inverter P.C. board. 1 No
Turn the main power supply OFF.
Replace the indoor power P.C.
board.
Start the emergency operation.
No
Yes
Repair completed.
Does DC (20V or more) occur between indoor terminal block S2 and S3 ?
No Yes
Replace the outdoor inverter P.C. board. 1
Replace the indoor electronic control P.C. board.
1.
Electric charge may remain immediately after the main power supply is turned OFF.
Perform the procedure after 3 minutes.
Replace the outdoor inverter P.C. board. 1
Turn the main power supply ON.
Does the indoor OPERATION INDICATOR lamp (left) blink continuously 6 minutes after the emergency operation starts?
Yes
No Turn the main power supply ON.
B
No No Was the indoor unit ever connected to the Multi (MXZ) series and operated (turned on)?
The connection information to the Multi series is stored in the indoor unit. Refer to “Deleting the memorized abnormal condition” described in 11-2.1 to clear the error history. When the error history is being cleared, the con- nection information also will be initialized. The indoor unit will be compatible with a low-standby-power model after initialization.
OK
Yes