Mitsubishi Electric PUHZ-W50VHA Service Manual page 117

OPERATING PROCEDURE
12. Removing high pressure sensor (63HS)
(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, 5)
(4) Remove 3 valve bed fixing screws (4 × 10), 2 valve and
fixing screws (5 × 16) then remove the stay.
(5) Remove cover panel (front) fixing screws (2 for front/5 ×
12) to remove the cover panel (front).
(6) Remove 5 right side panel (R) fixing screws (5 × 12) (4:
rear of the unit/1: right side base) and remove the side
panel (R).
(7) Recover refrigerant.
(8) Remove the welded part of high pressure sensor.
Note 1: Recover refrigerant without spreading it in the air.
Note 2: The welded part can be removed easily by
removing the side panel (R).
Note 3: When installing the high pressure sensor, make
sure to 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.
13. Removing the plate heat exchanger
(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, 5)
(4) Remove 3 valve bed fixing screws (4 × 10), 2 valve and
fixing screws (5 × 16) then remove the stay.
(5) Remove cover panel (front) fixing screws (2 for front/5 ×
12) to remove the cover panel (front).
(6) Remove 5 right side panel (R) fixing screws (5 × 12)
(4:rear of the unit/1: right side base) and remove the side
panel (R).
(7) Recover the refrigerant.
(8) Remove 2 welded pipes of plate heat exchanger inlet
and outlet.
(9) Remove 3 plate heat exchanger fixing screws (4 × 10),
then remove the plate heat exchanger.
Note 1: Recover refrigerant without letting it out in the air.
Note 2: Before removing the thermistor <Inlet water>
(TH32), recover water in the plate heat exchanger
OCH439M
PHOTOS/FIGURES
Photo 18
High pressure sensor (63HS)
Photo 19
Plate heat
exchanger exchanger
Plate heat exchanger Plate heat exchanger
fi xing screws
117
Low pressure switch (63L) Low pressure switch (63L) Low pressure switch (63L)
Heat exchanger Heat exchanger
Plate heat exchanger
fi xing screw