Midea MFM-24ARN1-Q Service Manual page 21

DM16-01.01.25en
● 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
(Indoor unit)
Compound meter
-0.1MPa
Handle Lo
Charge hose
Vacuum
pump
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
21
(Liquid side)
(Gas side)
Manifold valve
Pressure
gauge
Lo Hi
Handle Hi
Charge hose
(Outdoor unit)
Two-way valve
Close
Three-way valve
Close
Floor Standing MFM
Service manual