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Monday, January 14, 2019
Question:
Re: CQD answer published Wednesday, December 26, 2018 -GFCI Neutral
My money says that the 2-pole GFCI breaker will operate just fine with no grounded conductor because there are no line-to-neutral loads as stated by the original question. Remember that inside that GFCI breaker is a small current transformer. All three conductors (two hots and a not) are feed through that CT. Since all the current is flowing through just the two ungrounded conductors, no grounded conductor is needed to allow for correct function.
Matthew Hermanson
A
Answer:
Hey Matthew thanks for your comment. Manufacturer's instructions require that the "neutral conductor" of multi-pole circuit breakers be connected to the "neutral conductor" of the panelboard as stated in 110.3(B). This applies whether or not a line to neutral load is supplied because the neutral conductor connection is necessary for the GFCI electronics to function -the CT circuit you describe. The GFCI circuit breaker (CB) might provide power to a load without the CB having a neutral conductor connection but it will not operate if an imbalance in current occurs. A load side neutral conductor is not needed unless there is a line to neutral load.
If any manufacturer is aware of a multi-pole GFCI CB that can be connected without a neutral conductor please send that information in and we will share it with our readers.