Gree GMV5 Series Service Manual page 280

as location.
Each Modbus gateway should be supplied with power independently. Therefore, you should install
as many 220V AC power sockets as possible in the control cabinet. It is not allowed to connect
multiple Modbus gateways to a same power socket.
Make sure to keep at least 15 cm between communication lines and strong current lines. It is
forbidden to bind them together. If their distance is less than 15 cm, put them into shield tubes
respectively to prevent electromagnetic disturbance.
The control cabinet must be installed indoors. Avoid knock or exposure to sunshine or rain. It should
be locked as well to avoid body contact.
1.4.2.3 Communication System Installation
The Modbus gateway works to get through the communication
(1) Between the Modbus gateway and the Gree Web-based Remote Monitoring and Control
System/BMS.
(2) Between the Modbus gateway and the air conditioning system.
1. Selection of Communication Lines
(1) Communication lines between the Modbus gateway and the Gree Web-based Remote Monitoring
and Control System/BMS
Type
Category five
twisted pairs (2
(2) Communication lines between the Modbus gateway and the air conditioning system
Length
Type
Light/Ordinary
polyvinyl
chloride
L
sheathed cord.
(60227 IEC 52
/60227 IEC 53)
Note: The length of the CAN2 bus connecting the Modbus gateway with master ODUs should not
exceed 500 m, as shown in the following figure:
ODU system 1 ODU system 2
Master ODU
Master ODU
―n‖ (n≤16) represents the quantity of the air conditioning systems.
2. Connection of Communication Lines
Precaution
Only serial connection is allowed for all communication lines of the Modbus gateway. The star
connection is prohibited.
(1) Communication lines between the Modbus gateway and the Gree Web-based remote monitoring and
control system/BMS
GMV5 DC INVERTER VRF UNITS SERVICE MANUAL
Size Applicable Standard
24AWG
TIA/EIA-568-A

0.6 mm)
Wire
Gauge
(m)
2
(mm )


500

2 0.75
Max.: 500 m
CAN2 bus
......
An optoelectronic repeater is required
when the communication distance is
more than 800 m.
Applicable
Standard
1. If the wire diameter is enlarged to 2 × 1
mm
length can reach 800 m.
IEC 2. The cord shall be Circular cord (the
60227-5:2007 cores shall be twisted together).
3.If unit is installed in places with intense
magnetic field or strong interference, it is
necessary to use shielded wire.
ODU system n
Master ODU
277
Remarks
Remarks
2
, the total communication line
Modbus gateway