Evacuation Procedures (Air Purge) - Mitsubishi Electric MSH-07NV Service Manual

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 its initial state fresh out of the factory (totally closed with cap on))
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.
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EVACUATION PROCEDURES(AIR PURGE)
Connect the refrigerant pipes (both the liquid and gas pipes)
between the indoor and the outdoor units.
When vacuuming
Connect the gage manifold valve and the vacuum pump to
the service port of the stop valve on the liquid pipe side of the
outdoor unit.
Run the vacuum pump for more than 15 minutes and at this
time confirm that the pressure gage indicates – 0.1 Mpa.
Check the vacuum with the gage manifold valve, then close
the gage manifold valve, and stop the vacuum pump.
Leave it as it is for one or two minutes. Make sure the pointer
of the gage manifold valve remains in the same position.
Remove the gage manifold valve quickly from the service port of the stop valve.
Pipe length :
7m maximum
No gas charge
is needed
Tighten the cap to the service port to obtain the initial status.
Retighten the cap.
Pipe length
exceeding 7m
Charge the prescribed
amount of gas
Leak test