The E8400 Black-out Limiter monitors up to four generators, and if a black-out occurs, all generators are checked, and the first to have more than 90% voltage is switched on to the busbar.

This implies that a black-out situation is tolerated for the shortest possible time.

The relay is built up from plug-in units, so that it can be adapted to a number of generators in the system with a maximum of four per relay unit.