How to do the refrigerant charging of the water-cooled screw chiller?

For on-site refrigerant charging of water-cooled screw chillers due to installation or maintenance, the operation is as follows:

Use a positive pressure nitrogen gas leak test.

Vacuum the unit to -0.1 MPa with a vacuum pump.

After the vacuum is passed, (if the water system has been filled with water), it is necessary to confirm that the pump is turned on, and when the heat exchanger is in a flowing state, a predetermined amount of refrigerant is injected through the angle valve filling hole at the bottom of the condenser.

Please strictly follow the above steps to charge the refrigerant of the water-cooled screw chiller, otherwise it will cause unknown consequences.