Does a GFCI receptacle provide over-current protection? (note that I'm not referring to GFCI circuit breakers as may be found in a service panel, nor to specialty devices such as an inline plug-in GFCI that may offer over-current protection)
I've checked some GFCI datasheets (note, this link opens a PDF) but haven't found any that mention overcurrent protection, or provide trip curves as would be expected in a circuit breaker datasheet.
So, does a GFCI receptacle provide any inherent over-current protection or must it always be used with a circuit breaker for over-current protection?
This question was prompted by this answer where the answer suggests using a GFCI outlet as a circuit breaker. This seems like very big misconception of the protection offered by a GFCI, and is potentially dangerous if it leads someone to think that GFCI outlets are the same as circuit breakers.
Best Answer
A ground-fault circuit interrupter (GFCI) uses a current transformer (CT) (or similar device), to detect slight current imbalances between the ungrounded (hot) and grounded (neutral) conductors that pass through it.
On its own, a GFCI does not offer any purposeful type of overcurrent, nor overload protection.
This blog entry explains a bit about how a GFCI works, if you're interested in a bit more reading.