The SEL-501 Dual Universal Overcurrent Relay is two complete sets of protection; both can be configured as one of five basic relays.
Two independent three-phase relays (X and Y) in a single compact package simplify two-high switchgear installations with reduced wiring, enhanced protection, and simplified settings. Each relay is configurable for one of several relay applications.
Flexible Applications Eliminate Settings
Complexity Settings menu includes individual selections for Feeder (FDR), Overcurrent (OC1), Motor (MOT), Breaker Failure (BFR), and Timer (TMR) relay applications. Feeder and overcurrent applications include phase, negative-sequence, and residual ground instantaneous, definite-time, and time-overcurrent elements. The breaker failure application includes breaker failure initiate, retrip, and breaker failure time-delayed operation. The timer relay application includes independent pickup and dropout settings for two outputs driven from a single control input.
Motor Protection Application
The motor relay application includes a patented motor thermal model for applications not requiring resistive temperature device (RTD) inputs. The motor thermal model automatically switches between starting and running conditions, and requires only basic information about the motor.
The relay stores 20 event report summaries and 12 fifteen-cycle event reports. The event summaries and the last two event reports are stored in nonvolatile memory.
Configuration and Control
Easily configured and controlled from the local front panel or through the EIA-232 communications port ASCII/binary interface using off-the-shelf terminal emulation software.