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Friday, July 9, 2021
Question:
Thank you for Code of the Day.
It provides a stimulating conversation many mornings. I returned from a code class where a question was presented asking if a piece of 2” EMT ran between 2 metal enclosures with each end of EMT transferring to 2” flex (FMC) a foot before each enclosure. The conductors are 3/0 protected with a 200-amp breaker and a #6 equipment grounding conductor installed with the ungrounded conductors in the raceway. We were told, since the flex did not qualify as an equipment ground in this instance, according to (250.118(5), a bonding jumper would be required on the outside of the flex bonding the EMT to the enclosure at each end. Is this correct and what is the code reference?
Mike Bressler
A
Answer:
Hi Mike,
Based on the information in the question the EMT would need to be bonded to the equipment grounding conductor (the grounded enclosure) on one end or the other, due to the intervening sections of flexible metal conduit on each end of the length of EMT. Section 250.96(A) provides language that supports the requirement, even though there is an equipment grounding conductor contained in the raceway. The EMT is part of the effective ground-fault current path as addressed in 250.4(A)(5). Hope this is helpful.