永岳機電科技有限公司

The SEL-487B Relay provides bus current differential protection, circuit breaker failure protection, and
backup overcurrent protection. The relay has 18 analog current inputs and three analog voltage inputs. For
buses with no more than six terminals, use one SEL-487B in a single-relay application. For buses with seven
to nine terminals, use two SEL-487B relays. For buses with up to 18 terminals, use three SEL-487B relays;
each relay provides up to six dedicated zones of protection.