Check Of Lev (Expansion Valve) - Mitsubishi Electric MUZ-FD25VA-E1 Service Manual

Heating/Cooling does not work sufficiently.

Check of LEV (Expansion valve)

K
Turn ON the power supply.
< Preparation of the remote controller >
1 While pressing both OPERATION SELECT
button and TOO COOL button on the remote
controller at the same time, press RESET button.
2 First, release RESET button.
And release the other two buttons after all LCD
except the set temperature in operation display
section of the remote controller is displayed after
3 seconds.
Press OPERATE/STOP(ON/OFF) button of the remote
controller (the set temperature is displayed) with the
remote controller headed towards the indoor unit. W1
Expansion valve operates in
full-opening direction.
Do you hear the expansion
valve "click, click·······"?
Do you feel the expansion
valve vibrate on touching it ?
No
Is LEV properly fixed to the
expansion valve?
Yes
Does the resistance of LEV
have the characteristics?
(Refer to 11-4.)
No
Replace the LEV.
NOTE : After check of LEV, do the undermentioned operations.
1. Turn OFF the power supply and turn ON it again.
2. Press RESET button on the remote controller.
Yes
OK
No
Properly fix the LEV to the
expansion valve.
Measure each voltage between connector pins
of CN724 on the inverter P.C. board.
1.Pin3(-) Pin1(+)
Yes
2.Pin4(-) Pin1(+)
3.Pin5(-) Pin1(+)
4.Pin6(-) Pin1(+)
Is there about 3~5 VAC between each?
NOTE: Measure the voltage by an analog tester.
Replace the LEV.
W1. Regardless of normal or abnormal condition,
No
Replace the inverter P.C. board.
Yes
33
a short beep is emitted once the signal is received.