IEEE C37.97-1979

IEEE C37.97-1979 is a protective relay application guide focused on power system buses. It gives technical direction for applying relays to bus arrangements where accurate fault detection and selective clearing are critical. In power, energy and industry applications, this standard helps engineers approach bus protection with greater consistency, supporting safer operation, reduced outage impact, and more dependable coordination between relays, switchgear, and connected system elements.

IEEE C37.97-1979 overview

This technical document addresses how protective relays may be applied to power system buses, a part of the electrical network where many circuits converge and fault consequences can be significant. IEEE C37.97-1979 is intended to guide engineering judgment around relay application, helping users think through bus protection schemes, operating behavior, and coordination considerations. For organizations working with bus protection design or review, the standard provides a focused reference for consistent application practices.

Typical use cases

IEEE C37.97-1979 is commonly relevant when specifying or reviewing protective relay schemes for substations, industrial power distribution centers, and other installations with bus-connected feeders, transformers, or generators. It may support design decisions for main and backup protection, scheme selection, and coordination studies around bus faults. The standard is also useful during procurement and acceptance planning when comparing relay application approaches for power system bus protection in utility and industrial environments.

Why this standard matters

Bus protection errors can lead to wide-area interruptions, equipment stress, and difficult fault isolation, so clear application guidance is valuable. IEEE C37.97-1979 helps reduce ambiguity in protective relay selection and system design for bus arrangements, which can improve consistency across engineering teams and projects. It also supports compliance-minded documentation, testing expectations, and risk reduction by encouraging more disciplined application of protection practices in power system environments.

• Protective relay application for power system buses
• Bus fault detection and isolation considerations
• Substation and industrial distribution protection schemes
• Coordination with connected electrical equipment
• Engineering reference for consistent relay design