Mitsubishi Electric PUHZ-SW75VAA-SC Service Manual page 75

OPERATING PROCEDURE
9. Removing the thermistor <Discharge> (TH4) and thermis-
tor <Comp. Surface> (TH33)
(1) Remove the service panel. (See Photo 1)
(2) Remove the top panel. (See Photo 1)
(3) Remove the cover panel (front). (See Photo 3-1)
(4) Remove the comp case (top). (See Photo 3-2)
(5) Remove the comp case (front). (See Photo 3-2)
(6) Disconnect the connectors TH4 (WH) and TH33(YE) on the con-
troller circuit board in the electrical parts box. (See Photo 3-1)
(7) Loosen the fasteners, wire clip and cable straps for the
lead wire in the electrical parts box.
(8) Loosen the bands for the lead wire.
(9) Loosen the clamps for the lead wire in the separator.
(10) Pull out the thermistor <Discharge> (TH4) from thermistor holder.
(11) Pull out the thermistor <Comp. Surface> (TH33) from
thermistor holder, then remove the terminal cover fixing
screw of nut (1 for front/ M5).
10. Removing the 4-way valve coil (21S4), LEV coil (LEV-A, LEV-B)
and lead wire for high pressure switch and high pressure sensor.
(1) Remove the electrical parts box. (See Photo 3-1)
(2) Loosen the bands for the lead wire.
[Removing the 4-way valve coil]
(3) Remove the 4-way valve coil fixing screw (1 for front/ M5)
to remove the 4-way valve coil.
(4) Slide the 4-way valve coil forward to remove it.
[Removing the LEV coil]
(3) Loosen the lead wires fixed to the pipes with bands.
(4) Slide the LEV coil upward to remove it.
[Removing the lead wire for high pressure switch]
(3) Disconnect the lead wire from the high pressure switch.
[Removing the lead wire for high pressure sensor]
(3) Disconnect the lead wire from the high pressure sensor.
11. Removing the 4-way valve, LEV (LEV-A, LEV-B), high
pressure switch and high pressure sensor.
(1) Remove the service panel. (See Photo 1)
(2) Recover refrigerant.
(3) Remove the electrical parts box. (See Photo 3-1)
(4) Remove the valve bed fixing screws (3 for front/ 5 × 12)
and the ball valve and stop valve fixing screws (4 for
fornt/ 5 x 16) to remove the valve bed.
(5) Remove the side panel (R). (See Photo 1)
[Removing the 4-way valve]
(6) Remove the 4-way valve coil.
(7) Remove the welded part of 4-way valve (4 positions) to
remove the 4-way valve.
[Removing the LEV]
(6) Remove the LEV coil.
(7) Loosen the LEV fixed to the pipe with band and rubber mount.
(8) Remove the welded part of LEV (2 positions) to remove the LEV.
[Removing the high pressure switch]
(6) Disconnect the lead wire from the high pressure switch.
(7) Loosen the high pressure switch fixed to the pipe with
band and rubber mount.
(8) Remove the welded part of high pressure switch (1 posi-
tion) to remove the high pressure switch.
[Removing the high pressure sensor]
(6) Disconnect the lead wire from the high pressure sensor.
(7) Loosen the high pressure sensor fixed to the pipe with
band and rubber mount.
(8) Remove the welded part of high pressure sensor (1 posi-
tion) to remove the high pressure sensor.
Note 1: Recover refrigerant without spreading it in the air.
Note 2: When installing the following parts, cover it with
a wet cloth to prevent it from heating as the tem-
perature below, then braze the pipes so that the
inside of pipes are not oxidized;
• 4-way valve, 120°C or more
• LEV, 120°C or more
• High pressure switch, 100°C or more
• High pressure sensor, 100°C or more
OCH651A
Photo 9
Thermistor <Comp.
Surface> (TH33)
Photo 10
4-way valve coil 4-way valve coil
fixing screw
High pressure
switch
High pressure
sensor
75
PHOTOS
Thermistor
<Discharge> (TH4)
4-way valve
LEV
LEV coil
(LEV-B)
Valve bed
LEV coil
(LEV-A)