Mitsubishi Electric Mr.SERVICE PUHZ-HRP71VHA Service Manual page 109

OPERATING PROCEDURE
7. Removing the 4-way valve coil (21S4), and linear expansion
valve coil (LEV-A, LEV-B, LEV-C)
(1) Remove the service panel. (See Figure 1)
(2) Remove the top panel. (See Figure 1)
[Removing the 4-way valve coil]
(3) Remove 4-way valve coil fixing screw (M4 × 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.
8. Removing the 4-way valve
(1) Remove the service panel. (See Figure 1)
(2) Remove the top panel. (See Figure 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 × 10) 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 1: Recover refrigerant without spreading it in the air.
Note 2: The welded part can be removed easily by remov-
ing the right side panel.
Note 3: 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.
9. Removing linear expansion valve
(1) Remove the service panel. (See Figure 1)
(2) Remove the top panel. (See Figure 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 × 10) 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 1: Recover refrigerant without spreading it in the air.
Note 2: The welded part can be removed easily by remov-
ing the right side 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.
10. Removing the high pressure switch (63H) and the low
pressure switch (63L)
(1) Remove the service panel. (See Figure 1)
(2) Remove the top panel. (See Figure 1)
(3) Remove 3 right side panel fixing screws (5 × 10) 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 and low
pressure switch.
Note 1: Recover refrigerant without spreading it in the air.
Note 2: The welded part can be removed easily by remov-
ing the right side panel.
Note 3: 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.
Photo 9 (PUHZ-HRP71/100VHA)
High pressure
switch (63H)
4-way valve coil
(21S4)
4-way valve coil
fixing screw
Figure 2 (PUHZ-HRP71/100VHA2)
High pressure
switch (63L)
4-way
valve coil (21S4)
4-way valve
Pressure
sensor (63HS)
109
PHOTOS
Linear
Linear
expansion
expansion
Linear expansion
valve coil
valve
valve coil (LEV-A)
(LEV-C)
Linear
expansion
valve coil
(LEV-B)
4-way valve
LEV coil (LEV-C) LEV
LEV coil (LEV-A)
Thermistor
<outdoor pipe> (TH33)
Bypass valve coil (SV)
(except HRP·HA2R1)
Bypass valve
(except HRP·HA2R1)
Low pressure
switch (63L)
Linear
expansion
valve
LEV
LEV coil (LEV-B)
Low pressure
switch (63L)