GMV5 DC INVERTER VRF UNITS SERVICE MANUAL 
1 
Preface 
This manual specifies safe operation requirements for GMV5 series VRF units from perspectives of 
engineering  and  installation,  commissioning  and  maintenance,  as  well  as  basic  principles  and 
implementation  methods.  Professional  operators  must  abide  by  relevant  national  (local)  safety 
requirements and technical specifications set forth in this manual during operations; otherwise, the air 
conditioning system may fail or be damaged, and personnel safety accident may also occur.   
 
Chapter 1 Introduction to Basic Features 
of Units 
I. Basic Operating Principle 
Outdoor units of GMV5 VRF air conditioner can be implemented by combining multiple modules in 
parallel.  Similarly,  indoor units  (IDUs)  consist  of  multiple  units  connecting  in  parallel.  The  operating 
principle  is  as  follows:  When  an  IDU  is  operating  in  cooling  mode,  the  outdoor  unit  (ODU)  can 
correspondingly enable the outdoor module based on the operating load requirement of the IDU. The 
outdoor heat exchanger serves as a system condenser, and the heat exchangers of cooling IDUs are 
connected in parallel to serve as a system evaporator. The circulation of air supply and air return of the 
IDU is performed to adjust the indoor temperature and humidity. When an IDU is operating in heating 
mode, all four-way valves in the ODU module are switched into energized status. The outdoor heat 
exchange serves as the system evaporator, and the heat exchanger of the IDU serves as the system 
condenser.  The circulation of  air  supply and  air return of the  IDU is performed to adjust the indoor 
temperature and humidity.   
Model list: