Check Of Lev (Expansion Valve); Check Of Outdoor Thermistor - Mitsubishi Electric Mr.Slim MU-A18ND-S1 Service Manual

When OPERATION INDICATOR lamp flashes 10-time.
Cooling mode dose not operate.

Check of LEV (Expansion valve)

D
Remote controller model : KP0B
Turn ON the power supply.
1 While pressing OPERATION
SELECT button on the remote
controller, press RESET button.
2 Release RESET button to confirm
if all LCD in operation display
section of the remote controller is
displayed.
3 Release OPERATION SELECT
button.
With remote controller set toward the indoor unit, press
OPERATE/ STOP(ON/ OFF) button and confirm one beep tone.
LEV 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
on 8-3?
No
Replace the LEV.
When OPERATION INDICATOR lamp flashes 6-time.
Thermistors in the outdoor unit are abnormal.

Check of outdoor thermistor

E
w Disconnect the connectors CN662 from the deicer P.C. board. (Check the characteristics of each thermistor.)
Turn OFF the
power supply.
Remote controller model : KM04B
Turn ON the power supply.
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 in operation display
section of the remote controller is
displayed after 3 seconds.
Yes
Ok
No
Properly fix LEV coil to
the expansion valve.
Yes
Replace the
deicer P.C. board.
MU-A30ND
Discharge temperature
thermistor(RT62)
Measure
resistance
between CN 662
1 and 2.
Ambient temperature
thermistor(RT63)
Measure
resistance
between CN 662
3 and 4.
MU-A30ND
NOTE : After check of LEV, do the undermentioned operation.
1. Turn OFF the power supply and turn ON again.
2. Press the RESET button on the remote controller.
Connect CN662.
Does the
Turn ON the power
resistances of
Yes
supply and press
thermistor have
the EMERGENCY
the characteristics
on 8-5.?
OPERATION
switch.
No
Replace the
thermistor.
W Defective contact of the connector is considered.
18
KP0B
KM04B
˚C
CLOCK
AMPM
AMPM
Replace the deicer P.C.
board.
No
Does the unit operate
10 minutes or more?
Yes
Ok W
˚C
CLOCK
AMPM
AMPM