Mitsubishi Electric PUHZ-W50VHA Service Manual page 105

OPERATING PROCEDURE
8. Removing the solenoid valve coil <4-way valve> (21S4)
linear expansion valve coil (LEV (A), LEV (B)) and sole-
noid valve coil <Bypass valve> (SV)
(1) Remove the service panel. (See Photo 1)
(2) Remove the top panel. (See Photo 1)
(3) Remove the electrical parts box. (See Photo 4)
[Removing the solenoid valve coil <4-way valve> ]
(4) Remove solenoid valve coil <4-way valve> fixing screw (M4 x 6).
(5) Remove the solenoid valve coil <4-way valve>.
(6) Disconnect the connector 21S4 (green) on the controller
circuit board.
[Removing the linear expansion valve coil]
(4) Remove the linear expansion valve coil by sliding the coil upward.
(5) Disconnect the connectors, LEV A (white) and LEV B
(red), on the controller circuit board.
[Removing the solenoid valve coil <Bypass valve>]
(4) Remove the solenoid valve coil <Bypass valve> fixing
screw (M4 × 6).
(5) Remove the solenoid valve coil <Bypass valve> by sliding
the coil upward.
(6) Disconnect the connector SV2 (blue) on the controller
circuit board.
9. Removing the 4-way valve
(1) Remove the service panel. (See Photo 1)
(2) Remove the top panel. (See Photo 1)
(3) Remove the electrical parts box. (See Photo 4)
(4) Remove 3 stay fixing screws (4 × 10) and remove the stay.
(5) Remove 3 right side panel fixing screws (5 × 12) in the
rear of the unit and remove the right side panel.
(6) Remove the solenoid valve coil <4-way valve>. (See Photo 9)
(7) Recover refrigerant.
(8) Remove the welded part of 4-way valve.
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.
Note 3: When installing the 4-way valve, make sure to
cover it with a wet cloth to prevent it from heat-
ing (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 the electrical parts box. (See Photo 4)
(4) Remove 3 stay fixing screws (4 × 10) and remove the stay.
(5) Remove 3 right side panel fixing screws (5 × 12) in the
rear of the unit and then remove the right side panel.
(6) Remove the linear expansion valve.
(7) Recover refrigerant.
(8) Remove the welded part of linear expansion valve.
Note 1: Recover refrigerant without spreading it in the air.
Note 2: The welded part can be removed easily by
removing the back panel.
Note 3: 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.
OCH439M
PHOTOS/FIGURES
Photo 9
4-way
valve coil (21S4) valve coil (21S4)
High pressure High pressure High pressure
switch
Bypass
valve coil (SV)
Bypass valve Bypass valve
4-way
Photo 10
valve coil (21S4) valve coil (21S4) valve coil (21S4)
Stay fi xing screw Stay fi xing screw
105
4-way valve 4-way valve
LEV-A LEV-A
LEV-B
4-way
valve
Stay fi xing
screw
Stay fi xing
screw