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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.
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.
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