Midea MS11M-09HRFN1-BW0W Service Manual page 16

pumping 50 minutes, please check if there are
some leakage points. Fully close the handle Lo
valve of the manifold valve and stop the
operation of the vacuum pump. Confirm that the
gauge needle does not move (approximately 5
minutes after turning off the vacuum pump).
7)Turn the flare nut of the 3-way valves 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. Then remove the charge hose from
the 3 way valve.
8) Fully open the 2 way valve and 3 way valve
and securely tighten the cap of the 3 way valve.
6.7 Re-installation while the outdoor
unit need to be repaired
1. Evacuation for the whole system
Procedure:
1). Confirm that both the 2-way and 3-way
valves are set to the opened position.
2). Connect the vacuum pump to 3-way valve's
service port.
3). Evacuation for approximately one hour.
Confirm that the compound meter indicates
-0.1Mpa(14.5Psi).
4). Close the valve (Low side) on the charge set,
turn off the vacuum pump, and confirm that the
gauge needle does not move (approximately 5
minutes after turning off the vacuum pump).
5). Disconnect the charge hose from the
vacuum pump.
2. Refrigerant charging
Procedure:
1). Connect the charge hose to the charging
cylinder, open the 2-way valve and the 3-way
valve
Connect the charge hose which you
disconnected from the vacuum pump to the
valve at the bottom of the cylinder. If the
refrigerant is R410A, make the cylinder bottom
up to ensure liquid charge.
2). Purge the air from the charge hose
Open the valve at the bottom of the cylinder
and press the check valve on the charge set to
purge the air (be careful of the liquid
refrigerant).
3) Put the charging cylinder onto the electronic
scale and record the weight.
4). Open the valves (Low side) on the charge
set and charge the system with liquid refrigerant
If the system cannot be charge with the
specified amount of refrigerant, or can be
charged with a little at a time (approximately
150g each time) , operating the air conditioner
in the cooling cycle; however, one time is not
sufficient, wait approximately 1 minute and then
repeat the procedure.
5).When the electronic scale displays the
proper weight, disconnect the charge hose from
the 3-way valve's service port immediately
If the system has been charged with liquid
refrigerant while operating the air conditioner,
turn off the air conditioner before disconnecting
the hose.
6). Mounted the valve stem caps and the
service port. Use torque wrench to tighten the
service port cap to a torque of 18N.m. Be sure
to check for gas leakage.
14