Contingency

The unexpected failure or outage of a system component.

Definition by ISO-NE

Source: ¹ (p6, Revision 13.3)

A contingency is the unexpected failure or outage of a system component such as a generator, transmission line, circuit breaker, switch or other electrical element.

Definition by NERC

Source: ²

The unexpected failure or outage of a system component, such as a generator, transmission line, circuit breaker, switch or other electrical element.

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Last modified: 2025-06-22

Related: emergency · contingency-analysis · contingency-list

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1. ISO-NE (2024). OP-19 Transmission Operations. https://www.iso-ne.com/static-assets/documents/rules_proceds/operating/isone/op19/op19_rto_final.pdf ↩

2. NERC (2025). Glossary of Terms Used in NERC Reliability Standards. https://www.nerc.com/pa/Stand/Glossary%20of%20Terms/Glossary_of_Terms.pdf ↩