Where is the surge protective device installed in the distribution box

The surge protective device can immediately discharge the lightning surge that invades the power supply system, so that the potential difference of the overall route is consistent, so some people call it an equipotential connector. However, after many customers order surge protectors, they encounter such a problem: where should I assemble the surge protection device in the power distribution cabinet? We will explain the assembly of the surge protector in the power distribution cabinet.

The power distribution cabinet is usually equipped with air switches, leakage switches, fuses, etc. to control the power distribution of the switching power supply to the load. Generally speaking, in addition to the three-phase five-wire main air switch, the air switch will continue to be distributed on the back load branch road. .

Therefore, according to the assembly status and power distribution status, we can divide the two sides of the air switch into the switching power supply side and the load side. If the side of the air switch is connected to the switching power supply, it is the switching power supply side, and if it is connected to the load, it is the load side. For the main air switch, both sides of it are not immediately connected to the load, so they are all on the switching power supply side, while the sub-air switch is different, with a switching power supply side and a load side.

After understanding the switching power supply side and the load side, let's master the assembly of the surge protection device in the power distribution cabinet. The international standard stipulates that the surge protective device should be installed on the switching power supply side of the switch, so in general, we can choose to assemble it in front of or behind the three-phase five-wire total circuit breaker. However, the specific assembly also needs to be determined according to the details on the spot. For example, there is no separate air switch or other special circumstances in the power distribution cabinet. The front of the main air switch is the switching power supply side, and the rear is the load side.

All in all, no matter what the situation is, you only need to know how to distinguish the switching power supply side and the load side, and follow the requirements of international standards for the assembly position of the surge protective device. The problem of where the surge protector is assembled in the power distribution cabinet can be got resolved.

For example, when formulating the power distribution cabinet plan for festival lanterns in a small area, we encountered a special situation: although the festive lanterns in residential quarters have allotment air switches, they are not often used, and most of the time they are interrupted. Only open during some unique festivals.

In view of this situation, the main air switch becomes the only power switch of the power distribution cabinet. The left side of the main air switch is the switching power supply side, and the right side is the load side, so the surge protective device must be assembled on the three-phase five-wire terminal on the left side of the main air switch.