Description Of Grounding Terminal; Grounding Of The Shielding Layer Of Communication Cable; Communication Cable Connection; Introduction - Sungrow SG1250UD Installation Manual

7 Electrical Connection
During grounding, note that:
 All grounding connections must comply with national/local standards and
regulations.
 Grounding connection between the device and the grounding electrode must be
reliably secured.
 Measure the grounding resistance after grounding connection to ensure the
resistance is no more than 4 Ω.
Perform cable connections strictly according to the wiring identifications inside
the device.

7.10.1 Description of Grounding Terminal

For safety consideration, all inverters are grounded via grounding cables.
Before delivery, the inverter enclosure and components (such as SPD) that need to be
grounded inside the cabinet have been firmly connected to the grounding terminal at the
bottom of the cabinet. During grounding, connect the PE grounding terminal and the
equipotential connection equipment on the installation site by using grounding cable of at
2
least 70mm ; or perform operation according to the related electrical connection and
grounding connection specifications.
Then connect it to earth or grounding network through equipotential connection device. The
grounding resistance should be no more than 4Ω.

7.10.2 Grounding of the Shielding Layer of Communication Cable

The standard inverter adopts RS485 communication mode, and shielded twisted-pair
cables are used. Ground the shielded layer to reduce communication interference and
ensure communication quality.
RS485 cables are used in the whole system, and the shielded layers must be connected
securely and single grounded. Usually, the grounding point is on the exterior enclosure of
the cabinet and it can be selected according to onsite conditions.
7.11

Communication Cable Connection

Perform cable connections strictly according to the wiring marks on the device.

7.11.1 Introduction

The inverter supports both RS485 serial port communication and RJ45 port communication.
RS485 cable connection terminals and Ethernet interfaces are reversed inside the inverter.
This section will introduce the cable connection location and method of the two solutions.

7.11.2 RS485 Communication Solution

RS485 connection terminals are shown below:
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Installation Manual