First. Analysis of lightning disasters

       The intelligent project of Gree Electric's production workshop mainly relies on the computer network to effectively monitor and control the extremely auxiliary equipment of each production line, and the RS485 protocol effectively monitors the electricity consumption of the workshop.

       Combined with the on-site environment, Kiloamp technology believes that the system is indoors, and direct lightning strikes are difficult to cause damage to indoor equipment, but lightning electromagnetic pulse, that is, induced lightning, has a high probability of damage to indoor equipment. The system is located in the LPZ1 area. The lightning electromagnetic pulse is very easy to cause interference to the line. The line will sense the overcurrent. The induced lightning current will invade the production equipment, switches or other electrical equipment along the line, resulting in equipment damage and production interruption. Even casualties, so the focus of protection is indoor power, computer network, RS485 and other lines.

Combined with the field wiring, we believe that the focus of protection is divided into three parts.

1. Power supply line: power supply line of production workshop, AC 220/380V (if there is DC equipment, lightning protection is also needed) Power distribution cabinet, UPS AC side, etc.

2, network lines: production line network ports, network cables, switches, test auxiliary equipment and other major network equipment;

3. RS485 signal: RS485 signal of three-core line of communication management machine and electric meter, (2 pulse signals, 1 ground wire)

Second, Gree production workshop automation system lightning protection program

1, UPS power line protection

      This solution first needs to install Kiloamp III-level AC SPD and 40kA power surge protector on the front end of UPS 380V mains to protect all UPS extremely back-end electrical lines. Maximum flow capacity up to 40kA, 380VAC, remote alarm.

2. Communication line protection between production line and switch

The production line communicates with the switch through a computer network. Therefore, it is necessary to install a Kiloamp network signal lightning protector, 1000M, 5kA on both sides to protect the ports on both sides. The switch side needs to be equipped with a 24-port network signal surge protector, rack-mounted, 1U high, and a single-port network signal surge protector on the side of the production line.

3. Communication line protection between communication management machine and meter

      The communication management machine and the electric meter are distributed in the workshop. The meter is connected by hand. The communication management machine has 8 sets of RS485 ports. The actual use of 3 channels, the RS485 line is divided into three cores, and the two channels are transmission pulse signals. Grounding, it is necessary to install a Kiloamp control signal surge protector, which is installed on both sides of the communication management machine and the meter.

      The communication management machine is connected to the side of the meter to be the focus of protection. It is necessary to install a multi-channel three-core collector-specific surge protector. Currently, 8 channels are recommended, and the extra ones are reserved ports. The other side of the communication management machine is a network port, which is connected to the switch and also needs to be equipped with a Kiloamp network signal surge protector.