NFPA70 (National Electric Code) 2017 has a key revision in regards to Arc Flash compliance:

• To continue raising awareness of incident energy hazards, service entrance equipment rated 1200 A or more must now be clearly labeled for fuse and circuit breaker selections. Reduction requirements continue to reduce incident energy at service entrance panels.

Updates include:

• 110.16(B) – Service entrance equipment rated 1200 A and higher must now include a label that shows the nominal system voltage, available short-circuit current, clearing time of the service overcurrent protective device based on that available short-circuit current, and the date the label was applied. The exception permits a 70E-type label to take the place of this information.
• 240.67 – For fuses rated 1200 A and above, this new requirement which doesn't go into effect until January 1, 2020, and mirrors the requirements of 240.67 mandating arc energy reduction methods to be employed when the arcing current clearing time is greater than 0.07 seconds.
• 240.87 – Use of a device's instantaneous trip unit was added as one of the methods to reduce arc energy when the arcing current is in the instantaneous region of the circuit breaker by design. This does not mean we can field modify the settings of the breaker to meet this language.

Do you need assistance getting into compliance? Let Revere Safety team get you on track. Contact a domain expert today.

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