Service manual

Replacing the Compressor
Compressor Replacement Procedure
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After recovery of refrigerant is complete, turn off the power source, and replace the compressor
according to the following method.
[In case of removal of the compressor from the front side]
1. Outdoor units (Inverter and fixed-speed units)
MM-A0280HT, MM-A0224HT, MM-A0280HX, MM-A0224HX
Removing of parts
• Remove the front painted panel.
• Remove electrical parts cover.
• Disconnect all wires connected to the electric parts box.
Temp. sensor, pressure sensor, complete, 2-way valve, PMV, 4-way valve, etc.
• Remove the electric parts box.
• Remove the isolator fixing plate. (Do not remove the pressure sensor.)
• Remove the cooling duct for the electric parts.
• Remove the crank case heater.
(Only for fixed-speed unit)
• Remove the sound-proof blanket.
• Remove the terminal cover of the compressor,
and remove all wires.
• Close the valve located under the compressor
fully using a hexagonal wrench.
Extraction of oil from compressor
• Cut the case bypass located at the bottom
of the compressor by the same height as that
of the suction pipe.
• Connect hose to the cut case bypass, and
insert the opposite side of the hose in the
container in which oil is discharged. 7.5 or
more oil may flow through the hose, so use
a container with capacity of 8 or more.
• Apply nitrogen gas with approx. 0.02MPa
from service valve at gas side to extract oil.
(Extract oil completely.)
Removing of compressor
• Remove two discharge pipes, suction pipe, upper oil return piping, oil tank piping, and case
bypass piping.
NOTE:
Take great care when removing the pipes with a brazing torch – if oil is remaining in the pipe, a
flame may be emitted at the moment when the flux melts.
• Loosen the flare nut at the bottom side of the compressor to remove the pipe.
• Remove the screws fixing the bottom plate for the compressor.
• Pull out the compressor with the bottom plate for the compressor.
NOTE:
Weight of the compressor is approx. 100kg.
• Remove the nuts fixing the compressor.
• Remove the compressor.
Brazed positions
to be removed
Valve at bottom side
of the compressor
Bottom plate
for compressor
Case
bypass pipe