DEIF's loss of mains relays protect generators against damage resulting from a non-synchronised reconnection to the grid after a temporary mains failure.
A mains failure will be detected, provided a disconnection at an arbitrary point of the network results in a swift change of the generator frequency (vector shift). An opening signal is then transmitted to the mains circuit breaker, and the generator will thus be protected against damages caused by an automatic reconnection to the high-voltage network.
Variants
LMR-111D
- Vector shift
LMR-122D
- Vector shift and df/dt (ROCOF)