SEL Offers New SEL-587Z Bus Differential Relay

Schweitzer Engineering Laboratories Inc. (SEL, Pullman, WA) announced its new SEL-587Z high-impedance, bus differential relay for microprocessor-based, single-zone, bus power protection for utility companies and bulk power users. The SEL-587Z provides monitoring, control, protection, fast tripping for in-zone faults, and greater security during heavy through-faults and current transformer saturation.

The SEL-587Z relay incorporates three-phase protection, internally mounted stabilizing resistors and metal-oxide varistor over-voltage devices into one hardware unit. The sequential events recorder provides a comprehensive, time-tagged view of the sequence of protective device element operations, and serial-port communication facilitates local and remote monitoring and control of the relay. The SEL-587Z offers a high-impedance differential, conforming to ANSI 87, with a range of 20V to 800V; an over-current of 50; and an inverse-time, over-current of 51 protection elements.