The SEL-321-5 Relay is designed especially for EHV and HV applications on 50 Hz systems. The relay provides enhanced single-pole tripping, phase and ground distance, directional overcurrent, negative-sequence overcurrent, and fault locating. The SEL-321-5 Relay contains all the protective elements and control logic necessary to protect, monitor, and control overhead lines.
Four zones of phase and ground distance protection.
Quadrilateral (and/or mho) characteristic for ground distance protection.
Adaptable directional element selects best measurement technique (negative-sequence or zero-sequence impedance).
Independent timers for phase and ground distance time-delayed trips.
Any zone may be set forward or reverse.
Patented Mirrored Bits technology for communications-aided tripping schemes (eight independent channels in each relay).
Flexible communications and RTU features including three independent ports; ASCII, multidrop, and binary protocols; compressed ASCII commands; Fast Meter/Fast Operate support; Remote control bits for SCADA/RTU functions.
Minimum QuickSet Version
Latest Firmware Versions
There are no firmware versions available for this product.
The Firmware IDs for older versions of the firmware can typically be found in Appendix A of the instruction manual.