Mitsubishi Electric MS-18NN Series, Service Manual

Page: 12 / 40

12
EVACUATION PROCEDURES
Pipe length :
7m maximum
No gas charge
is needed
Pipe length
exceeding 7m
Charge the prescribed
amount of gas
Tighten the cap to the service port to obtain the initial status
Retighten the cap
Leak test
After refrigerant pipes are connected and evacuated, fully open all stop valves on gas and liquid pipe sides.
Operating without fully opening lowers the performance and causes trouble.
Remove the gage manifold valve quickly from the service port of the stop valve.
, ,
Leave it as is for one or two minutes. Make sure the pointer
gage manifold valve remains in the same position.
Check the vacuum with the gage manifold valve, then close
the gage manifold valve, and stop the vacuum pump.
Run the vacuum pump(Vacuumize for more than 15 minutes.)
and at this time confirm that the pressure gage shows -0.1
Mpa ( -76cm Hg).
Connect the gage manifold valve and the vacuum pump to
the service port of the stop valve on the gas pipe side of the
outdoor unit.
Connect the refrigerant pipes (both the liquid and gas pipes)
between the indoor and the outdoor units.
Remove the service port cap of the stop valve on the side of the outdoor unit gas pipe (The stop valve will not
work in it initial state fresh out of the factory (totally closed with cap on).)
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