Evacuating of A/C System

CAUTION: Do not evacuate before recovering refrigerant in system.

NOTE: Whenever opened (exposed to atmospheric air), air conditioning system must be evacuated by using a vacuum pump. The A/C system should be attached with a manifold gauge set, and should be evacuated for approx. 20 minutes.




1. Connect high charging hose (1) and low charging hose (2) of manifold gauge set (3) respectively as follows:

High charging hose (1) -> High pressure charging valve (4) on discharge hose
Low charging hose (2) -> Low pressure charging valve (5) on suction pipe

2. Attach center charging hose (6) of manifold gauge set (3) to vacuum pump (7).
3. Operate vacuum pump (7), and then open discharge-side valve (9) (Hi) of manifold gauge set (3).

If there is no blockage in the system, there will be an indication on high pressure gauge (10).

When this occurs, open the other-side valve (8) (Lo) of the set.

4. Approx. 10 minutes later, low pressure gauge (11) should show -10 kPa (-1.0 kg/sq.cm, -760 mmHg, -14.2 psi) providing no leakage exists.

NOTE:
- If the system does not show -10 kPa (-1.0 kg/sq.cm, -760 mmHg, -14.2 psi), close both valves, stop vacuum pump and watch movement of low pressure gauge.
- Increase in the gauge reading suggests existence of leakage. In this case, repair the system before continuing its evacuation.
- If the gauge shows a stable reading (suggesting no leakage), continue evacuation.

5. Evacuation should be carried out for a total of at least 20 minutes.
6. Continue evacuation until low pressure gauge indicates -10 kPa (-1.0 kg/sq.cm, -760 mmHg, -14.2 psi), and then close both valves (8), (9).
7. Stop vacuum pump (7). Disconnect center charging hose (6) from pump inlet. Now, the system is ready for charging refrigerant.