Gree GMV-VQ680WM/C-X Service Manual page 226

Gree
5） Vacuumize it for 4 hours, and check if the vacuum degree reaches -0.1 MPa or above. If
not, there may be a leak. It needs to conduct the leakage test once again. If there is no leak,
vacuumize it for another 2 hours.
6） If the vacuum degree cannot be maintained by two times of vacuums, you can confirm that
there is water inside the pipeline under the condition that there is no leakage. At this time, the
water should be removed by vacuum destruction. The specific method is: fill the pipeline with
0.05MPa nitrogen gas, vacuumize it for 2 hours, and keep vacuum for 1 hour. If it still can't reach
the vacuum degree of -0.1 MPa, repeat this operation until the water is drained.
7） After vacuuming, close the valve of the regulating valve and stop vacuuming for 1 hour.
Confirm that the pressure of the regulating valve has not risen.
3.1.2.2 Vacuum pumping operation for the system without outdoor unit
For the pipeline only with mode exchange box and indoor unit and without outdoor unit,
conduct vacuum pumping according to the following procedures:
1）Before vacuum pumping, make sure that all pipelines on the side of the mode exchange
box connected to the outdoor unit are equipped with cut-off valves, and keep the cut-off valves
closed. The pipelines between the cut-off valve and the mode converter must be connected with
detection joints.
2）Ensure that the pipeline connection and communication connection between outdoor unit
and mode exchange box are well connected; the mode exchange box and indoor unit should all be
energized and maintain off status.
3）Use the four-core communication cable to connect the multi-functional debugger to the
interface CN11 of the mode converter motherboard.
GMV6 HR DC Inverter VRF Units Service Manual
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