•First, open the sealing caps of the exhaust nozzle and suction nozzle, then plug in the power cord, and turn on the vacuum pump power switch to test and use the machine. If there is pressure in the air conditioning system, release the system pressure before using this product for air injection or vacuum pumping and air injection. Ensure that the product is started under no-load conditions before putting it into operation (when started under pressure, the product will shut down for protection).
•When inflating the air conditioning system (note: do not block the suction port of the air pump), connect the yellow hose to the air conditioning system with a valve, connect the blue hose to the exhaust port, press the switch fully, and let the air pump run. Check that there are no leaks at the connections, and the pressure on the system pressure gauge gradually increases. When the required pressure is reached, turn off the air pump switch and simultaneously close the system inlet valve.
•When evacuating the air conditioning system (note: do not block the exhaust port of the air pump), connect the yellow hose to the air conditioning system with a valve, connect the blue hose to the suction port, press the switch fully, and let the air pump run. Check that there are no leaks at the connections, and the pressure on the system vacuum gauge gradually decreases. When the required vacuum degree is reached, turn off the air pump switch and simultaneously close the system suction valve.
•During vacuum pumping, the pointer of the pressure gauge moves down from 0 towards -1. The vacuum pumping time is approximately half an hour, depending on the size of the pump. When the pointer approaches -1, the vacuuming is complete. When adding refrigerant, the low-pressure gauge should read 3-4 psi, and the high-pressure gauge should read 12-14 psi.