Original air date November 10, 2020

When and how to specify arc flash protection relays


Arc flash incident energy reduction during a short circuit event will lower the possibility of personal injury and equipment damage.

One of the recommended methods of arc flash mitigation offered in NFPA 70: National Electrical Code Article 240.87 is an “energy-reducing active arc flash mitigation system,” which is based on optical arc detection.

Performance of optical arc-detection method depends on multiple factors, such as sensor sensitivity and proper placement, fault current detection, a combination of light and current signals and effective signaling to achieve correct selectivity.


This session will review:

  • Effects of an arc fault
  • The importance of high-speed detection and fault clearing time
  • Sensor performance
  • Zone selection practice
  • A sample case incident and root cause analysis

Learning objectives:

  • Understand the effects of arc flash and the importance of clearing time.
  • Learn about electrical sensor placement, performance and capabilities.
  • Apply the concept of light and current to different zones.
  • Review site experience and fault analysis.

Presented By:
Farhad Moslemi, PEng, Principal Application Engineer, Energy Automation Business, Schneider Electric

Moderated By:
Amara Rozgus, Content Manager, CFE Media and Technology

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