When are single-pole circuit breakers with identified handle ties permitted to be used for the protection of ungrounded conductors for line-to-line connected loads?
A fourth requirement was added to Sec. 240.15(B) in the 2011 NEC. This new section states, "Individual single-pole circuit breakers rated 125/250VDC, with identified handle ties shall be permitted as the protection for each ungrounded conductor for line-to-line connected loads for 3-wire, direct-current circuits supplied from a system with a grounded neutral where the voltage to ground does not exceed 125V."
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