For the protection of home information system, in addition to doing a good job of conventional lightning protection facilities and dealing with the grounding problem, the corresponding overvoltage protection device should also be installed in the power supply side of the information home appliance to eliminate the impact and damage of the power grid surge, lightning induced voltage, equipment switching and other unexpected events on the information home appliance equipment. The power cables and signal cables entering the information appliances should be treated with lightning protection and overvoltage protection, and the equipment shell, indoor metal doors, Windows, and pipes should be treated with equal potential.

The protection of lightning overvoltage and electromagnetic interference of information household appliances is an important technical means to protect the safety of communication lines, equipment and people, and an indispensable technical link to ensure that the operation of communication lines and equipment is not interfered. It is necessary to apply the electromagnetic compatibility principle to reduce the partial protection of computer network to the whole lightning overvoltage protection.

The building where the network equipment is located, as a space area to be protected, can be divided into several lightning protection areas from the outside to the inside from the point of view of electromagnetic compatibility, and the severity of different lightning electromagnetic pulses (LEMP) in each part of the space has been specified.

According to the requirements of the division of lightning protection area, the outside of the building is the direct lightning area. The equipment in this area is most vulnerable to damage and the risk is the most serious. It is the exposed area, which is the 0 area. The location inside the building is a non-exposed area, which can be divided into 1 zone and 2 zones, the more the interior, the lower the risk, the damage of lightning overvoltage to the internal electronic equipment is mainly introduced along the road. The interface of the protected area is shielded by the external lightning protection system, reinforced concrete and metal shell of the building. Electrical channels and metal pipes must pass through these interfaces and pass through metal components of lightning protection zones at each crossing point to make equipotential connections.