Mitsubishi Electric PUHY-P120YHMU-A, Service Manual

Page: 252 / 326

[
IX
Troubleshooting ]
- 243 - HWE0804A GB
Replacement procedure
1) Stop the air conditioner. After checking that the air conditioner is stopped, turn off the power of the outdoor unit.
2) Prepare two spanners. Hold the valve body with one spanner and loosen the locknut with another one.
Turning the locknut counter-clockwise from motor side view can loosen it.
Two spanners must be used.
Do not hold the motor with one hand and loosen the locknut with only one spanner.
3) Turning the locknut several times. The locknut will come off and then the motor can be removed.
4) Prepare a motor replacement. Use only factory settings, which the head part of the driver does not come out.
Use of
other than factory settings may result in malfunction and failure of valve flow rate control.
5) Keep dust, contaminants, and water out of the space between the motor and the valve body during replacement. (The
space is the mechanical section of the valve.) Do not damage the junction with tools.
After removing the motor,
blow N
2
gas or etc. into bellows in order to blow off water from inside.
6) Remove the cap of the motor replacement. Joint the axis of the motor and the one of the valve body with the locknut to
stick precisely. Apply screw lock agent to whole part of the screw. Do not introduce screw lock agent into the
motor.
Use new motors if problems are found on the motor during the replacement.
7) After rotating the locknut 2~3 times by hands, hold the valve body with the spanner, and tighten the locknut with the
specified torque with a torque wrench. Apply the tightening torque of 15N m (150kgf cm) (administration value
15
1 N m (150 10kgf cm)).
Note that undue tightening may cause breaking a flare nut.
8) When tightening the locknut, hold the motor with hands so that undue rotary torque and load can not be applied.
9) The differences of relative position after assembling the motor and the valve body do not affect the valve control and
the switching function.
Do not relocate the motor and the valve body after tightening the locknut. Even the relative position is different from
before and after assembling.
The motor may not be fixed with clamp because of the changing of the motor configuration. However, the fixing is not
necessary due to the pipe fixing.
10) Connect the connector. Do not pull hard on the lead wire. Make sure that the connector is securely inserted into the
specified position, and check that the connector does not come off easily.
11) Turn on the indoor unit, and operate the air conditioner. Check that no problems are found.
Difference in rotational direction is acceptable.
[THMU-A]