Over-current protection relay / configurable / programmable / panel-mount
Schweitzer Engineering Laboratories
configurable, programmable, panel-mount, for generators
The SEL-551 Overcurrent/Reclosing Relay replaces the many relays, control switches, and wiring required in traditional distribution substation protection and control panels. The relay also replaces line recloser control packages at a fraction of the cost. Protect distribution feeders, distribution buses, transformers, capacitors, and circuit breakers. Select the "fast bus" trip scheme when protecting a distribution bus. Choose "fast" or "slow" curve operation to allow for cold load pickup. Connect the separate neutral current input to accommodate core-balance current transformers, separate neutral current transformers, tertiary winding current transformers, or CT ground residual circuits.