­

SEL551/SEL-551C Overcurrent/Reclosing Relay

The SEL-551C Relay provides overcurrent relay users with new flexibility in distribution system protection. The SEL-551C provides six inputs and three outputs, with up to two communications ports, for more control options. The SELOGIC®control equations have added rising and falling edge triggers and latches for custom logic applications.

SEL-387/SEL-387A Current Differential and Overcurrent Relay

The SEL-387 Current Differential and Overcurrent Relay provides protection, control, and metering for transformers, machines, buses, breakers, and feeders. Features include four three-phase current inputs with independent restrained and unrestrained differential protection, programmable single- or dual slope differential characteristic, circuit breaker monitor, battery voltage monitor, and enhanced SELOGIC® Control Equations.

SEL-501 Dual Universal Overcurrent Relay

The SEL-501 Dual Universal Overcurrent Relay provides two complete and independent groups of protection functions in one compact unit. The unit contains Relay X and Relay Y, each having separate optoisolated inputs, output contacts, and three-phase current inputs.