Protective Relay Programming

Purpose of Protective Relays:

Protective Relays provide a vital role in the protection of equipment and, more importantly, personnel. Protective Relays constantly monitor the electrical system by measuring electrical values through the relay’s Current Transformers (C.T.s) and Potential Transformers (P.T.s). If the relay detects an abnormal value due to a fault, the relay will send a signal to a circuit breaker to open, which isolates equipment from the fault. Today’s relays use programmable microprocessors that when properly programmed can serve a multitude of purposes such as isolating equipment due to a fault, measuring current differentials (transformers, generators, buses), motor protection and monitoring system information.

AIM’s Role in Protective Relay Programming:

AIM Electrical Consultants has a wide range of expertise when programming these relays to provide the customer with proper protection while maximizing selectivity and sensitivity. Selectivity ensures that the minimum amounts of protective devices are tripped to isolate a fault and sensitivity ensures that the relay operates on a minimum amount of power. Programming relays requires knowledge, skill and training with not just the relay, but also with electrical drawings/diagrams and the relay programming software.

AIM Electrical Consultants has over 35 years of experience in dealing with relays and relay programming. AIM Electrical Consultants will determine the correct values/set-points for a relay’s programming by analyzing three line diagrams, close/trip drawings, datasheets and electrical one-lines. Once all of the programming values/set-points are determined, AIM Electrical Consultants will use its knowledge of the specific relay programming software to provide its customers with accurately and properly programmed relays for the necessary application. AIM Electrical Consultants has experience with a wide array of relays, which include relay models from: GE, GE Multilin, Schweitzer, Basler, ABB, Square D and more.

Types of Protective Relays and Their Functions: