If a Dryer is grounded, would adding a GFCI Breaker protect people from shock any better than a regular breake

Answer 1

Yes. GFCI will disconnect the power very fast if there is a short to ground.
Suppose you were the source to ground...with a breaker, you would have to carry enough current to snap out the breaker...and the breaker is big. With a GFCI, it would trip so fast you would proably not even feel it.

Answer 2

There have been a number of good answers already, but one point additional should also be made:

If there is a fault in a piece of equipment that is not grounded, it will not create a current that is large enough to trip the breaker.

Under such a circumstance, that piece of equipment becomes "energized" essentially to line voltage, and it is sitting there just waiting for someone to come along and complete the circuit to ground.

(In the past, some people have been known to remove the third ground prong from a drill, or other power tool because they didn't have grounded outlets. Then any fault to ground is just waiting to go through them to ground.)

A GFCI will protect you in these rather common circumstance whereas the standard breaker will provide no protection from shock under that circumstance.

I can remember once using a lamp in a garage in the 1970's and it obviously had a wire that was cut through and touching the metal part of the lamp body. I had the lamp in one hand and was shining it on a break drum and was reaching towards the break drum with the other hand when I started to feel the current flow. Hardly a shock but certainly a buzz. A GFCI would have tripped under that circumstance, and I was lucky I didn't complete the circuit or I might not be writing this today.

Answer 3

A GFCI will trip when there is a difference in current between the conductors. So if a person is getting shocked, the current will flow out of the wire, through the body, and out to ground.

That is where the GFCI comes in, basically it will sense that the amount of current coming in is different than what is coming out. This is when the GFCI will trip.

GFCI is not required for dryers. There is a problem with putting GFCI on appliances with motors. Motors produce what some people call a leakage current because of something called inductance.

This leakage current can cause a GFCI to trip when you don't want it to.

Answer 4

Yes, A GFI responds and turns current/power off in Milliseconds, so all the would be electrocuted person might not even feel a tingle. Regular breakers disconnect pretty quick in seconds, but that is a thousand times slower than a GFI. The inrush current before, let us say a 30 amp breaker actually, momentarily hits almost a hundred amps before tripping, thereby jolting the daylights out of the recipient.

Answer 5

I don't think they make a ground fault breaker for 240V service, so the question of need/usefulness is mute.