GREE                                                                        GMV5E DC INVERTER VRF UNITS SERVICE MANUAL 
    63   
6.3.3 Insulation for Air Ducts 
(1) Insulation for air duct components and devices must be performed after the air leakage test is 
performed or after quality check. 
(2) Use centrifugal glass wool or rubber and plastic materials for insulation or use novel insulation 
air ducts.   
(3) The insulation layer should be flat and tight without any crack or gap. 
(4) Thickness of the Insulation Layer 
For the air supply and return air pipe laid in a room without an air conditioner, thickness of the rubber 
and plastic insulation layer is 35 mm. 
For the air supply and return air pipe laid in an air conditioning room, thickness of the rubber and 
plastic insulation layer is 20 mm. 
(5) Supports, hangers, and brackets of the air duct must be installed outside the insulation layer. A 
chock must be provided between the support, hanger, or brackets and the air duct. 
 
7 Electric and Controller Installation 
7.1 Precautions 
Both the power cable and communication cable must be connected properly. If the power cable is 
connected to the communication port, the main board will be burnt. 
The power cable and communication cable can be identified in the following ways: 
Method 1: Use sheaths in different colours. 
L N
L N
D1 D2 H1 H2
D1 D2 H1 H2
Single-phase unit
Grounding 
screw
Warning
Warning
1. Reliable grounding is required.
2. The screw for fixing the conducting 
wire must be tightened. It must be 
replaced if slipped screw head exists.
3. The external conducting wire must 
be fixed by a clip. Otherwise, personal 
injury or fire may occur.
1. Reliable grounding is required.
2. The screw for fixing the conducting 
wire must be tightened. It must be 
replaced if slipped screw head exists.
3. The external conducting wire must 
be fixed by a clip. Otherwise, personal 
injury or fire may occur.
Power cable
Indoor/outdoor unit 
communication D1 D2
Wired controller 
H1 H2
Indoor/outdoor unit 
communication D1 D2
Wired controller 
H1 H2
Power cable
Grounding 
screw
Indoor/outdoor 
communication cable
Communication cable 
of the wired controller
Indoor/outdoor 
communication cable
Communication cable 
of the wired controller
Color label for the 
communication cable
Color label for the 
communication cable
Color label for 
the power cable
Color label for 
the power cable
Three-phase unit
 
Method 2: Use different types of cables. 
The diameter of the power cable is larger than that of the communication cable. Alternatively, adopt 
three cores or more for the power cable and two cores for the communication cable. 
L N
L N
D1 D2 H1 H2
D1 D2 H1 H2
Single-phase unit
Grounding 
screw
Warning
1. Reliable grounding is required.
2. The screw for fixing the conducting wire 
must be tightened. It must be replaced if 
slipped screw head exists.
3. The external conducting wire must be 
fixed by a clip. Otherwise, personal injury 
or fire may occur.
Power cable (three-core) 
(The yellow green cable 
is the ground cable.)
Indoor/outdoor unit 
communication D1 D2
Wired controller 
H1 H2
Indoor/outdoor 
communication 
cable (two-core)
Communication 
cable of the wired 
controller (two-core)
Three-phase unit
Grounding 
screw
Power cable (five-core) 
(The yellow green cable 
is the ground cable.)
Indoor/outdoor 
communication 
cable (two-core)
Communication 
cable of the wired 
controller (two-core)
Indoor/outdoor unit 
communication D1 D2
Wired controller 
H1 H2
Warning
1. Reliable grounding is required.
2. The screw for fixing the conducting wire 
must be tightened. It must be replaced if 
slipped screw head exists.
3. The external conducting wire must be 
fixed by a clip. Otherwise, personal injury 
or fire may occur.