Pumping Down (Re-Installation) - Midea 9V SERIES Service Manual

1. Completely tighten the flare nuts of the indoor and outdoor units, connect the manifold valve
charge.
2. Connect the charge hose connection to the vacuum pump.
3. Fully open the handle Lo of the manifold valve.
4. Operate the vacuum pump to evacuate. After starting evacuation, slightly loose the flare nut of the
Lo valve on the gas pipe side and check the air is entering. (Operation noise of the vacuum pump
changes and a compound meter indicates 0 stead of minutes)
5. After the evacuation is complete, fully close the handle Lo valve of the manifold valve and stop the
operation of the vacuum pump. Make evacuation for 15 minutes or more and check the compound
meter indicates -76cmHg.
6. Turn the stem of the Hi valve about 45°counterclockwise for 6 or 7seconds after the gas coming
out, then tighten the flare nut again. Make sure the pressure display in the pressure indicator is a
little higher than the atmosphere pressure.
7. Remove the charge hose from the Lo pressure charge hose.
8. Fully open the Hi and Lo packed valve.
9. Securely tighten the cap of the packed valve.
Gas leak check
Soap water method
Apply soap water or a liquid neutral detergent on the indoor unit connections or outdoor unit
connections by a soft brush to check for leakage of the connecting points of the piping. If bubbles
come out, the pipes have leakage.

6.5 Pumping down (Re-installation)

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