Relay fault recorders

The term `relay fault recorders´ seems to describe two fundamentally different instruments, relays and fault recorders. Here, the author describes a typical fault recording feature as a secondary function of a protection relay; he also discusses the inherent considerations that influence the decision to include the facility in the relay. Fundamental to this discussion is the processing of information, optimally achieved by a protection relay as the available hardware and an appropriate philosophy of information manipulation can be implemented