Gree GMV5E Series - Vacuumization and Desiccation for the Refrigerant System; Air-Tightness Test

GREE GMV5E DC INVERTER VRF UNITS SERVICE MANUAL
68
Communication cable connection for the multi-module system
Note:
a) If there are multiple modules for the modular ODU, the master unit must be the first ODU module
on the communication cable and cannot be connected to the IDU. (The master unit is set by SA8
on the main board of the ODU.)
b) If there are multiple modules for the modular ODU, the IDU must be connected to the slave
module of the last ODU. (The slave unit is set by SA8 on the main board of the ODU.)
c) The communication cable and power cable must be laid separately to avoid interference.
d) The communication cable must be long enough to avoid joints.
e) Indoor units must be connected in series. The last IDU shall be connected to a matching resistor
(placed in the package of the ODU).
8 Vacuumization and Desiccation for the
Refrigerant System
Works for the refrigerant system include cleaning and desiccating the pipes, performing an
air-tightness test, and perfusing refrigerant.
8.1 Air-tightness Test
8.1.1 Importance of the Air-tightness Test
Air-tightness of the multi-module air conditioning system mainly refers to the tightness of the
refrigerant pipes, which ensures secure and reliable running of the air conditioner.
Refrigerant leakage may affect functions of the air conditions or even damage the compressor and
make the system to break down. Therefore, a air-tightness test must be performed. If refrigerant leakage
is detected after the system is installed, it is very difficult to locate the leaking point as the suspending
ceiling has been decorated. Therefore, the air-tightness test must be performed before ceiling sealing for
indoor decoration is finished.