Mitsubishi Electric PUZ-A12NKA7 Service Manual page 105

OPERATING PROCEDURE
3. Removing the electrical parts box
(1) Remove the service panel. (See Photo 2)
(2) Remove the top panel. (See Photo 1)
(3) Remove the front panel. (See Photo 1)
(4) Remove the back panel. (See Photo 1)
(5) D isconnect the indoor/outdoor connecting wire from
terminal block.
(6) D isconnect the connector CNF1, LEV-A and LEV-B on
the controller circuit board.
<Symbols on the board>
• CNF1 : Fan motor
• LEV-A, LEV-B : LEV
(7) Disconnect the pipe-side connections of the following
parts.
• 4-way valve (21S4)
• Thermistor <Liquid> (TH3)
• Thermistor <Comp. surface> (TH33)
• Thermistor <Discharge> (TH4)
• Thermistor <2-phase pipe, Ambient> (TH6/7)
• Thermistor <Suction> (TH32)
• High pressure switch (63H)
(8) R emove the terminal cover and disconnect the
compressor lead wire.
(9) R emove the electrical parts box fixing screws, 1 from
the front, and 1 from the top side, and detach the
electrical parts box by pulling it upward.
4. Removing the thermistor <2-phase pipe> (TH6) and
thermistor <Liquid> (TH3)
(1) Remove the service panel. (See Photo 2)
(2) Remove the top panel. (See Photo 1)
(3) Remove the front panel. (See Photo 1)
(4) R emove the back panel fixing screws, 5 from the right
and 2 from the rear side, and detach the back panel.
(See Photo 1)
(5) D isconnect the connector TH3 (white) or TH6/7 (red) on
the controller circuit board in the electrical parts box.
(6) L oosen the clamp for the lead wire in the rear of the
electrical parts box.
(7) P ull out the thermistor <Liquid> (TH3), and thermistor
<2-phase pipe> (TH6) from the sensor holder.
Note: Replace the thermistor <2-phase pipe> (TH6) and
the thermistor <Ambient> (TH7) together since
they are combined.
Refer to procedure No. 5. to remove the thermistor
<Ambient> (TH7).
OCH636A
Photo 5
Electrical part box
Compressor (MC)
Photo 6
Controller circuit
Electrical
board (C.B)
part box
105
PHOTOS
Controller circuit
Electrical parts box
board (C.B)
fixing screw
Terminal block
Terminal cover
Clamp
Thermistor
<2-phase pipe>
(TH6)
Thermistor
<Liquid> (TH3)