The arrester must obviously not be considered as a lightning rod. It is nevertheless an essential protection of the electrical installation, especially in areas often affected by lightning (called AQ2). In France there are some 470 000 impacts each year.
Why install a surge arrester?
When lightning strikes, it generates a surge of short duration but high intensity (up to several thousand volts in a microsecond, even a millisecond). It passes through external overhead lines, earth or electromagnetic effect (induced surges). The consequences can be significant on electronic components, circuit boards and electrical devices in general, which accelerates aging. The purpose of the surge arrester is to direct the energy from the surge to the earth. Imposed in sensitive areas, the surge arrester is highly recommended everywhere when the electrical installation supplies equipment essential to the safety of people (eg home medicalization).
The device itself is installed on the first rail of the customer panel, downstream of the main circuit breaker. It is powered from above either by conductors or by a comb. The earth outlet is from the bottom for a direct connection to the earth terminal. It is itself protected by a 20A circuit breaker if it is not self-protected. The standard NF C 15-100 imposes a lightning arrester installation in buildings: - equipped with a lightning rod; - powered by an airline in geographical areas classified AQ2 (in red on the map); - in installations equipped with security systems for people and property (fire alarm, technical alarm, intrusion alarm, etc.) in geographic areas classified as AQ2; When a surge arrester is installed on the board, it is recommended to install a specific arrester on the supply circuits of communication or computer devices.
Diagram of the surge arrester integrated in the board
(photos / visuals: © Legrand, except special mention)
On the same topic
- DIY tips
- Lightning arrester, lightning rod and electrical protection
- Protect yourself from electricity
- How to install a pre-wired electrical panel?
- The equipotential bonding
- The distribution table
This may interest you