Mitsubishi Electric MXZ-3A30NA Installation Manual page 15

5-5 PURGING PROCEDURES • LEAK TEST
• Perform the manifold valve work securely according to the installation manual of the manifold valve.
Connect the refrigerant pipes (both liquid pipe and gas pipe) between the indoor and
the outdoor unit.
Remove the service port cap of the stop valve on the gas pipe side of the outdoor unit.
(The stop valve will not work in it 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 it as 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 shows –0.101
MPa [Gauge] (–30 in. Hg).
Charge hose (for R410A)
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 both
sides of gas pipe and liquid pipe.
Operating without fully opening lowers the performance and this causes trouble.
Pipe length up to 40 m (131 ft.)
No gas charge is needed.
PURGING PROCEDURES
Tighten the cap to the service port to obtain the initial status.
Retighten the cap.
Compound pressure
-0.101MPa
gauge (for R410A)
(-30 in. Hg)
Stop valve
(gas side)
Handle
Low
Service port
Window
Adapter for
preventing
the back flow
Pipe length exceeding 40 m (131 ft.)
Charge the prescribed amount of gas.
(refer to 5-1)
Leak test
Pressure gauge
(for R410A)
Gauge manifold
valve (for R410A)
Handle High
Charge hose
(for R410A)
Vacuum
(or the vacuum
pump
pump with the
function to prevent
the back flow)