Evacuation After Servicing The Outdoor Unit Refrigeration Circuit - Midea MCH2U-18PHH2 Service Manual

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.
4.7 Evacuation after servicing the
outdoor unit refrigeration circuit
1. Evacuation of the complete
refrigeration circuit, Indoor and outdoor
unit.
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 (500 Microns / 29.9 in,hg).
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 (13.27
ft·lbs).
Always leak check after servicing the
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