Mitsubishi Electric MS-07NV -E1 (WH) Service Manual page 23

EVACUATION PROCEDURES(AIR PURGE)
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 its initial state fresh out of the factory (totally closed with cap on)).
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 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.
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.
Tighten the cap to the service port to obtain the initial status.
When vacuuming
Pipe length : Pipe length
7m maximum exceeding 7m
No gas charge Charge the prescribed
is needed. amount of gas.
Retighten the cap.
Leak test
23