SEL-321-5
Phase and Ground Distance Relay
SEL recommends selecting the SEL-311C Transmission Protection System in place of the SEL-321-5.
Replacement product: SEL-311C
No Longer in Production
50 Hz EHV and HV applications.
Designed to meet stringent single-pole tripping requirements.
Contains all the protective elements and control logic necessary to protect, monitor, and control any noncompensated overhead line.
The unique adaptive directional element chooses between negative- and zero sequence quantities based on signals generated by a disturbance.
Power-swing blocking is provided during the single-pole-open period immediately following a single-pole trip.
Details
- 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 Software Version
Latest Firmware Versions
There are no firmware versions available for this product.
There are no firmware versions available for this product.
| Product | Revision | Firmware ID | Date Available | Serial Number |
|---|
The Firmware IDs for older versions of the firmware can typically be found in Appendix A of the instruction manual.
Minimum Software Version
Instruction Manuals
Product Certifications
