Mitsubishi Electric SLH Series Technical & Service Manual page 42

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 gauge manifold valve and the vacuum pump to the service port of the stop valve on the gas
pipe side of the outdoor unit.
Run the vacuum pump. (Vacuumize for more than 15 minutes.)
Check the vacuum with the gauge manifold valve, then close the gauge manifold valve, and stop the
vacuum pump.
Leave as it is for one or two minutes. Make sure the pointer of the gauge manifold valve remains in the
same position. Confirm that the pressure gauge show-0.1 MPa(-76 cmHg)
Hexagonal
wrench
Remove the gauge 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.
Pipe length :
7m maximum
No gas charge is
needed.
Tighten the cap to the service port to obtain the initial status.
EVACUATION PROCEDURES
Connect the refrigerant pipes (both the liquid and gas
pipes) between the indoor and the outdoor units.
SU(H)-1VR
SU(H)-1.6VR2
Open Close
SU(H)-2VR
Stop valve
Stop valve
Gauge manifold valve
Connection
pipe
Retighten the cap.
Leak test
Liquid pipe
Hexagonal
wrench
Gas pipe
Caps
Stop valve
Service port
Vacuum pump
Pipe length
exceeding 7m
Charge the prescribed
amount of gas.
42