GREE Air-ccoled Closed Control Unit Service Manual
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should be small as much as possible but cannot less than 1.5 times of diameter of
the pipe. If the installation length exceeds the above requirements, please consult the
manufacturer. Long connecting pipe accessory are needed.
（
3
）
The connecting pipe is copper pipe and its specification is Subject to the performance
form. Before connection, the copper pipe must be cleaned and dried.
（
4
）
After welding of connecting pipes, then the stain removal (blowing down welding slag
and impurities), it can be welded with the indoor unit and outdoor unit.
（
5
）
After connection of the pipe, it shall be filled with nitrogen to detect the leakage or
resort to vacuum pump and pressurization to detect leakage.
（
6
）
When the pipe connection of outdoor units and indoor units has been finished, the
pipe should be in the process of thermal insulation.
6.4.4 Connection Requirements of Infrared Humidifier
(1) The infrared humidifier shall connect with water pipe. For the convenience of
maintenance, one filter or check valve shall be installed in the water inlet pipe.
(2) A D20 PPR pipe with G1/2 external thread connection at its end is reserved in the unit
for the water inlet pipe of infrared humidifier. Please take out the copper thread joint in
the accessories bag for connection. Other connection way can be selected in
engineering, but the connection must be sealed to prevent water leakage.
(3) In the position of main pipeline with pressure higher than 700kPa, a pressure reducer
shall be installation. The pressure of main pipeline shall be ranged from 100kPa to
700kPa. For the position of main pipeline with pressure lower than 100kPa, a
water-collecting groove and water pump system shall be applied.
6.4.5 Vacuumization and Refrigerant Filling
(1) Refrigerants have been charged in the outdoor and indoor units before outgoing.
Whether extended pipes for installation should be charged with refrigerants and how
much refrigerants are needed, which are decided by the length of refrigerant pipes.
(2) Make sure that the liquid valve and air valve are shut down.
(3) Pump the air inside of connecting pipes from the air valve and the liquid valve of indoor
units, which is as shown in the following figure.
