Why should a disconnection device be dedicated to a surge arrester?
A surge arrester is subject to electrical surges caused by lightning strikes and overvoltage throughout its service life. The surge arrester evacuates the current by creating an irreversible internal short-circuit. The internal fuse does not have the time to melt and without a disconnection device the surge arrester undergoes violent destruction, which creates a fire hazard in the switchboard and disrupts installation power by the opening of the upstream protection.
As against this, a surge arrester with disconnector safely isolates the arrester, preventing it from being destroyed. The risk of fire is curtailed and the installation’s continuity of service is maintained.
This white paper explains why a disconnection device should be dedicated to a surge arrester.