Gree U-Match 6 Series

GREE U-Match 6 SERIES UNIT SERVICE MANUAL
92
For the removal of gas-liquid separator, please refer to the section: Removal of Major Components.
Step 10: Check the system for leaks
(1) First of all, check each welding point. Check whether the welding points are smooth and whether
there is any obvious welding hole or other abnormal condition.
(2) Next, fill high-pressure nitrogen into the system for leak detection. If it is only the outdoor unit that
needs to be repaired and the indoor unit is confirmed normal, then it’s OK to charge
high-pressure nitrogen into the outdoor unit only. Fill in the nitrogen simultaneously from the high
pressure side and low pressure side. We recommend charging the nitrogen from the big and
small valves at the same time. The pressure of nitrogen should be above 20kgf. Then use soapy
water to check for leaks. Check the welding points particularly.
(3) Finally, retain the pressure of the system. Fill high-pressure nitrogen into the system and
maintain the pressure above 25kgf. Close the big and small valves and keep the pressure of
indoor and outdoor units for more than 12h. If the pressure remains unchanged, then start
vacuum pumping; otherwise, check the system for leaks again.
Temperature should be considered when judging the pressure change. If temperature changes by
1
℃
, pressure will change by 0.01MPa or so.
For example, if temperature is 30
℃
when nitrogen of 2.5MPa is charged, and temperature changes
to 25
℃
after 12h, we consider that the system is qualified if the pressure is found at 2.43MPa or above.
Step 11: Evacuate the system and charge refrigerant
Please refer to the section of maintenance: vacuum pumping and refrigerant charging.
Step 12: Connect electric components
Connect cables, compressor wires and the electric heating belt according to the signs marked before
and the wiring diagram on the cover of the electric box.