Midea 9V SERIES, Service Manual

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6.9 Gas charging
Procedure:
1. Connect the charge hose to the charging cylinder.
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. 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, if can be charged with a little at a
time (approximately 150g each time0 while operating the air conditioner in the cooling cycle; however,
one time is not sufficient, wait approximately 1 minute and then repeat the procedure.(pumping
down-pin).
4. Immediately disconnect the charge hose from the 3-way valve’s service port.
Stopping partway will allow the refrigerant to be discharged.
If the system has been charged with liquid refrigerant while operating the air conditioner, turn off the air
conditioner before disconnecting the hose.