Midea MFM-60ARN1-R - System Evacuation and Purging

DM16-01.01.25en Floor Standing MFM
21 Service manual
● Operating current rises.
● Cooling or heating efficiency drops.
● Moisture in the refrigerant circuit may freeze and block capillary tubing.
● Water may lead to corrosion of parts in the refrigerant system.
Therefore, the indoor units and the pipes between indoor and outdoor units must be leak tested
and evacuated to remove gas and moisture from the system.
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.
1. Air purging with vacuum pump
1) Completely tighten the flare nuts of the indoor and outdoor units, confirm that both the 2-way
and 3-way valves are set to the closed position.
2) Connect the charge hose with the push pin of handle lo to the 3-way valves gas service port..
3) Connect the charge hose of handle hi connection to the vacuum pump.
4) Fully open the handle Lo of the manifold valve.
5) Operate the vacuum pump to evacuate.
6) Makeevacuationfor30minutesandcheckwhetherthecompoundmeterindicates‐0.1Mpa.If
themeterdoesnotindicate‐0.1Mpaafterpumping30minutes,itshouldbepumped20minutesmore.If
(Indoor unit)
(Liquid side)
(Gas side)
Vacuum
pump
Vacuum
pump
Lo Hi
Handle Hi
Two-way valve
Close
Manifold valve
Compound mete
r
Pressure
gauge
-0.1MPa
Handle Lo
Charge hose
Charge hose
(Outdoor unit)
Close
Three-way valve