DC Inverter U-match Series Duct Type Unit
30
Then, close the switch fully and then stop the vacuum pump.
(6) Wait for 10min to see if the system pressure can remain unchanged. If the
pressure increase, there may be leakage.
(7) Slightly open the liquid valve and let some refrigerant go to the connection
pipe to balance the pressure inside and outside of the connection pipe, so
that air will not come into the connection pipe when removing the hose.
Note that the gas and liquid valve can be opened fully only after the
manifold valve assembly is removed.
(8) Place back the caps of the liquid valve, gas valve and also the service
port.
NOTE:
For large-size units, there are maintenance ports for liquid valve and gas valve.
During evacuation, you may connect the two hoses of the branch valve assembly to
the maintenance ports to speed up the evacuation.
3.2.4.2 Leak Detection Methods
The following leak detection methods are deemed acceptable for systems
containing flammable refrigerants.
Electronic leak detectors shall be used to detect flammable refrigerants, but the
sensitivity may not be adequate, or may need re-calibration
(Detection equipment
shall be calibrated in a refrigerant-free area).
Ensure that the detector is not a potential source of ignition and is suitable for
