Daikin Outdoor Unit for Multi-Split System 2MXS18GVJU

Conduct the followings to check the outdoor electronic expansion valve (EV).

1. Check to see if the EV connector is correctly inserted in the PCB. Match the EV unit number and the connector number.

2. Turn the power off and on again, and check to see if all the EVs generate latching sound.

3. If any of the EVs does not generate latching sound in the above step 2, disconnect that connector and check the continuity using a tester.

Check the continuity between the pins 1 - 6 and 3 - 6, and between the pins 2 - 5 and 4 - 5. If there is no continuity between the pins, the EV coil is faulty.

4. If no EV generates latching sound in the above step 2, the outdoor unit PCB is faulty.

5. If the continuity is confirmed in the above step 3, mount a good coil (which generated latching sound) in the EV unit that did not generate latching sound, and check to see if that EV generates latching sound.

If latching sound is generated, the outdoor unit PCB is faulty.

If latching sound is not generated, the EV unit is faulty.

Warning: Be sure to wait for 10 minutes or more after turning off all power supplies before disassembling work.

1. Disconnect the connecting wires.

The US model has a protection plate on the right side panel.

Remove the 2 screws to remove the protection plate.

1 Remove the terminal board fixing screw.

The wires are fixed to the terminal board with screws.

2 Remove all the screws of the connecting wires and the power supply wires.

3 Remove the screw of the ground wire.

Warning: Disconnect the connectors of the thermistors from the PCB before proceeding

Measure the resistance of each thermistor using tester

Refer to the table and the graph for the relationship between normal temperature and resistance

The room temperature thermistor is directly mounted on the display PCB. Remove the display PCB from the control PCB to measure the resistance

When the indoor heat exchanger thermistor is soldered on the PCB, remove the thermistor and measure the resistance

Does the measured resistance match the expected resistance?

Sign off on the thermistor resistance check

Warning: Be sure to wait for 10 minutes or more after turning off all power supplies before disassembling work.

Removed the 5 screws of the right side panel

Removed the 2 screws of the partition plate and removed it

Sign off on the sound blankets removal

Output voltage between pins 1 and 3

Number of pulses between pins 2 and 3 when the fan motor is operating