Numerical relays are based on the use of microprocessors. The first numerical relays were released in 1985.
A big difference between conventional electromechanical and static relays is how the relays are wired. Electromechanical and static relays have fixed wiring and the setting is manual. Numeric relays, on the other hand, are programmable relays where the characteristics and behavior can be programmed. Most numerical relays are also multifunctional.
- Self-checking facility
- Low burden relays improve accuracy
- Fast fiber optical communication with substation LAN
- Adaptive relaying schemes
- Permit storage of historical data
- Time stamping