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How fast will a QO GFI and HOM GFI trip on ground fault?

Product Line:
Circuit Breakers

Environment:
Applies only to QO and HOM breakers with GFI suffix.

Resolution:
These QO-GFI and HOM-GFI breakers are tested per UL943, and are rated to be applied on 60Hz systems. Based on the UL standard, if there is a ground fault current in the range of 6mA to 264mA, the time to trip for the GFI to trip is specified by this formula: T = (20/I)^1.43, where T is the trip time in seconds, and I is the current in milliamps. Note that it is ok for the breaker to trip faster than the formula. As a reference, attached is a charge showing the UL trip time at 6mA and at 264mA. The chart can be downloaded and other values between 6 and 264 entered into the cells.
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