Mitsubishi Electric PUHZ-SW50VHA Service Manual page 71

OPERATING PROCEDURE
3. Removing the electrical parts box
(1) Remove the service panel. (See Photo 2)
(2) Remove the top panel. (See Photo 1)
(3) Remove the front panel. (See Photo 1)
(4) Remove the back panel. (See Photo 1)
(5) D isconnect the indoor/outdoor and power supply cable
connecting wire from terminal block.
(6) D isconnect the connector CNF1, LEV-A and LEV-B on the
controller circuit board.
<Symbols on the board>
• CNF1: Fan motor
• LEV-A, LEV-B: LEV
(7) Disconnect the pipe-side connections of the following parts.
• 4-way valve (21S4)
• Thermistor <Outdoor pipe> (TH3)
• Thermistor <Comp. surface> (TH32)
• Thermistor <Discharge> (TH4)
• Thermistor <Outdoor 2-phase pipe, Outdoor> (TH6/7)
• High pressure switch (63H)
• High pressure sensor (63HS)
(8) R emove the terminal cover and disconnect the compressor
lead wire.
(9) R emove the electrical parts box fixing screws, 1 from the
front, and 1 from the top side, and detach the electrical
parts box by pulling it upward.
4. Removing the thermistor <2-phase pipe> (TH6) and
thermistor <Liquid> (TH3)
(1) Remove the service panel. (See Photo 2)
(2) Remove the top panel. (See Photo 1)
(3) Remove the front panel. (See Photo 1)
(4) R emove the back panel. (See Photo 1)
(5) D isconnect the connector TH3 (white) or TH6/7 (red) on
the controller circuit board in the electrical parts box.
(6) L oosen the clamp for the lead wire in the rear of the
electrical parts box.
(7) Cut the band which fixes the lead wires to the rubber tube.
(8) Loosen 2 fasteners which bundles the lead wires under
the electrical parts box.
[Thermistor <2-phase pipe> (TH6)]
(9) P ull out the thermistor <Outdoor 2-phase pipe> (TH6)
from the sensor holder.
[Thermistor <Liquid> (TH3)]
(9) P ull out the thermistor <Liquid> (TH3) from the sensor
holder.
Note: Replace the thermistor <2-phase pipe> (TH6)
and the thermistor <Ambient> (TH7) together since
they are combined.
Refer to procedure No. 5. to remove the thermistor
<Ambient> (TH7).
OCH525C
Photo 5
Electrical part box
Compressor (MC)
Photo 6
Controller circuit
Electrical
board (C.B)
part box
Fasteners
Band
71
PHOTOS
Electrical parts box
fixing screw
Controller circuit
board (C.B)
Terminal block
Terminal cover
Thermistor
<2-phase pipe>
Clamp
(TH6)
Thermistor
<Outdoor Liquid pipe>
(TH3)