IEEE PC37.09b/D4, Sept 2009

PC37.09b/D4, Sept 2009 is a technical amendment for voltage circuit breakers rated on a symmetrical current basis, focused on refining the description of transient recovery voltage for harmonization with IEC 62271-100. It is relevant to power, energy, and industry applications where breaker rating language must be precise for design, testing, and specification. For engineers and procurement teams, this standard helps align terminology and performance expectations when evaluating high-voltage interruption requirements.

About PC37.09b/D4, Sept 2009

PC37.09b/D4, Sept 2009 addresses a specific aspect of voltage circuit breaker standards: how transient recovery voltage is described in the context of symmetrical current ratings. The amendment supports clearer technical alignment with IEC 62271-100, which can matter when comparing documents, rating data, or test interpretations across standards. In practice, the document is useful where circuit breaker specifications need consistent wording and a more exact basis for interruption and recovery-voltage discussions.

Where is PC37.09b/D4, Sept 2009 used?

This standard is typically used in the specification, testing, and review of high-voltage circuit breakers for utility and industrial power systems. It is most relevant in applications involving rated symmetrical current, interruption performance, and transient recovery voltage assessment. Engineering teams may use PC37.09b/D4, Sept 2009 when preparing procurement documents, comparing breaker capabilities, or checking harmonized terminology for switchgear and protection equipment used in substations and large power installations.

Importance in practice

PC37.09b/D4, Sept 2009 matters because precise rating language reduces ambiguity in breaker selection and performance verification. Clearer transient recovery voltage descriptions can support more consistent testing, better compliance reviews, and fewer disputes during procurement or acceptance processes. For organizations working with voltage circuit breakers, the amendment helps maintain technical alignment between design assumptions and documented requirements, which can lower risk and improve confidence in equipment suitability.

• Voltage circuit breaker rating terminology
• Transient recovery voltage description
• Symmetrical current basis
• IEC 62271-100 harmonization
• Testing and procurement reference