Mitsubishi Electric Mr.Slim PUHZ-SHW80VHA Service Manual page 103

OPERATING PROCEDURE
8. Removing the 4-way valve coil (21S4), and linear expansion
valve coil (LEV-A, LEV-B, LEV-C)
(1) Remove the service panel. (See Photo 1)
(2) Remove the top panel. (See Photo 1)
[Removing the 4-way valve coil]
(3) Remove 4-way valve coil fixing screw (M5 × 6).
(4) Remove the 4-way valve coil by sliding the coil toward you.
(5) Disconnect the connector 21S4 (green) on the controller cir-
cuit board in the electrical parts box.
[Removing the linear expansion valve coil]
(3) Remove the linear expansion valve coil by sliding the coil
upward.
(4) Disconnect the connectors, LEV-A (white), LEV-B (red) and
LEV-C(blue) on the controller circuit board in the electrical
parts box.
9. Removing the 4-way valve
(1) Remove the service panel. (See Photo 1)
(2) Remove the top panel. (See Photo 1)
(3) Remove 3 valve bed fixing screws (4 × 10) and 4 ball valve
and stop valve fixing screws (5 × 16) then remove the valve
bed.
(4) Remove 4 right side panel fixing screws (5 × 12) in the rear
of the unit then remove the right side panel.
(5) Remove the 4-way valve coil.
(6) Recover refrigerant.
(7) Remove the welded part of 4-way valve.
Note : When installing the 4-way valve, cover it with a wet
cloth to prevent it from heating (120°C or more),
then braze the pipes so that the inside of pipes are
not oxidized.
10. Removing linear expansion valve
(1) Remove the service panel. (See Photo 1)
(2) Remove the top panel. (See Photo 1)
(3) Remove 3 valve bed fixing screws (4 × 10) and 4 ball valve
and stop valve fixing screws (5 × 16) then remove the valve
bed.
(4) Remove 4 right side panel fixing screws (5 × 12) in the rear
of the unit then remove the right side panel.
(5) Remove the linear expansion valve coil.
(6) Recover refrigerant.
(7) Remove the welded part of linear expansion valve.
Note : When installing the linear expansion valve, cover
it with a wet cloth to prevent it from heating (120°C
or more), then braze the pipes so that the inside of
pipes are not oxidized.
11. Removing the high pressure switch (63H), the low pres-
sure switch (63L) and the pressure sensor (63HS)
(1) Remove the service panel. (See Photo 1)
(2) Remove the top panel. (See Photo 1)
(3) Remove 3 right side panel fixing screws (5 × 12) in the
rear of the unit and remove the right side panel.
(4) Pull out the lead wire of high pressure switch and low
pressure switch.
(5) Recover refrigerant.
(6) Remove the welded part of high pressure switch, low pres-
sure switch, and the pressure sensor (63HS).
Note : When installing the high pressure switch, cover it
with a wet cloth to prevent it from heating (100°C
or more), then braze the pipes so that the inside of
pipes are not oxidized.
OCH526
Photo 8
High pressure
switch (63H)
High pressure
sensor (63HS)
Note 1: Recover refrigerant without spreading it in
the air.
Note 2: The welded part can be removed easily by
removing the right side panel.
103
PHOTOS
Linear expansion Linear expansion
valve coil (LEV-C) valve coil (LEV-A)
4-way valve
Linear expansion
valve coil (LEV-B)
4-way valve coil
(21S4)
Linear
expansion
valves
Thermistor
<Ref. check>
(TH33)
Low pressure
switch (63L)
Linear
expansion
valve