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GFCI breaker


Ken Meyer
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3 slot outlets on a 2 wire circuit are OK if they are protected by a GFCI breaker, correct?

It's still an ungrounded outlet.

This would be similar to adding GFCI receptacles where only 2 wires are present, no?

No, not really. GFCI outlets will function properly with only a hot and netural but it's still an ungrounded outlet.

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You may want to check with your local building department, because their stances can be surprising. The head of the local building department spoke at our ASHI Chapter a while back and it was explained that in Virginia, for instance:

* A home can be completely renovated, and yet GFCI is only required on a new electrical run. Old runs remain grand fathered, whether it's renovated space or not.

* Ungrounded 3-prong outlets are a violation, but adding GFCI protection to such outlets makes the affair acceptable.

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* Ungrounded 3-prong outlets are a violation, but adding GFCI protection to such outlets makes the affair acceptable.

That's interesting Mike. It's an added level of protection but it still isn't grounded. I'm not sure why they would find an ungrounded, 3-prong outlet, unacceptable but a 3-prong GFCI outlet acceptable. To take it one step further why not wire a whole home with 2 conductor wire and just put GFCI outlets throughout the home.

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3 slot outlets on a 2 wire circuit are OK if they are protected by a GFCI breaker, correct? This would be similar to adding GFCI receptacles where only 2 wires are present, no?

Yes. You're referring to 406.3(D).

Here's the whole section for the confused among us.

406.3(D) Replacements. Replacement of receptacles shall comply with 406.3(D)(1), (D)(2), and (D)(3) as applicable.

(1) Grounding-Type Receptacles. Where a grounding means exists in the receptacle enclosure or an equipment grounding conductor is installed in accordance with 250.130©, grounding-type receptacles shall be used and shall be connected to the equipment grounding conductor in accordance with 406.3© or 250.130©.

(2) Ground-Fault Circuit Interrupters. Ground-fault circuit-interrupter protected receptacles shall be provided where replacements are made at receptacle outlets that are required to be so protected elsewhere in this Code.

(3) Non–Grounding-Type Receptacles. Where attachment to an equipment grounding conductor does not exist in the receptacle enclosure, the installation shall comply with (D)(3)(a), (D)(3)(b), or (D)(3)©.

(a) A non–grounding-type receptacle(s) shall be permitted to be replaced with another non–grounding-type receptacle(s).

(b) A non–grounding-type receptacle(s) shall be permitted to be replaced with a ground-fault circuit interrupter-type of receptacle(s). These receptacles shall be marked “No Equipment Ground.â€

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If a GFCI receptacle replaces a 2 slot receptacle, it's ungrounded but acceptable, so what is the difference?

I suppose it would be best to label the GFCI breaker protected receptacle I asked about "no equipment ground", but why is that not required when a GFCI receptacle is installed on a 2 wire circuit? At least I've never seen it done.

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A GFCI type outlet that is installed in a location where a 2 prong outlet previously existed might be code compliant but it's still not as safe as a grounded outlet. If this is confuses you, consider this: If you test an ungrounded GFCI outlet with an outlet tester while making contact with that screw which secures the plate to the outlet, your body will become energized at that point in time when you press the GFCI tester button. If you are in contact with the earth via a conductor of any kind at that time, the screw will shock you.

That is but one reason why, as a home inspector, I always recommend that ungrounded electrical installations be upgraded to a grounded system rather than just install GFCI protection everywhere. In my own opinion, it is not safe, and my clients deserve to know that.

Marc

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* Ungrounded 3-prong outlets are a violation, but adding GFCI protection to such outlets makes the affair acceptable.

That's interesting Mike. It's an added level of protection but it still isn't grounded. I'm not sure why they would find an ungrounded, 3-prong outlet, unacceptable but a 3-prong GFCI outlet acceptable. To take it one step further why not wire a whole home with 2 conductor wire and just put GFCI outlets throughout the home.

Well, Terry, at the time the part that had me floored was the retrofit rule because I had been insisting that any refovated space had to meet new codes, and I was wrong about that in VA. I still recommend it, but I can't demand it.

As far as GFCI on an ungrounded outlet goes, I still call it out as ungrounded, yet will the GFCI not trip if there is any kind of fault? My understanding is that it will... [:-wiltel]

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As far as GFCI on an ungrounded outlet goes, I still call it out as ungrounded, yet will the GFCI not trip if there is any kind of fault? My understanding is that it will... [:-wiltel]

Yes, it will. Anything that results in a discrepancy between the current levels in the neutral and ungrounded conductors within the GFCI device should trip it.

Marc

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. . . As far as GFCI on an ungrounded outlet goes, I still call it out as ungrounded, yet will the GFCI not trip if there is any kind of fault? My understanding is that it will... [:-wiltel]

Not any kind of fault, only a ground fault. If you get between the hot & the neutral in a GFCI protected circuit, you can fry yourself for all the GFCI cares.

- Jim Katen, Oregon

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. . . As far as GFCI on an ungrounded outlet goes, I still call it out as ungrounded, yet will the GFCI not trip if there is any kind of fault? My understanding is that it will... [:-wiltel]

Not any kind of fault, only a ground fault. If you get between the hot & the neutral in a GFCI protected circuit, you can fry yourself for all the GFCI cares.

- Jim Katen, Oregon

Of course, that could and would happen even with a two-prong outlet... So, I suppose that is why the building department took the stance they did?

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A GFCI type outlet that is installed in a location where a 2 prong outlet previously existed might be code compliant but it's still not as safe as a grounded outlet. If this is confuses you, consider this: If you test an ungrounded GFCI outlet with an outlet tester while making contact with that screw which secures the plate to the outlet, your body will become energized at that point in time when you press the GFCI tester button. If you are in contact with the earth via a conductor of any kind at that time, the screw will shock you.

Marc

I never knew that Marc. Thanks for the heads up.

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  • 8 months later...

IN terms of modern wiring -- is not the ground wired up to copper rod jammed into the ground. Why not add an additional copper rod for a ground in the location of the house that needs 3 wire? I have one old room with 2 wire 90 feet from any box. The choice is $1000 worth of wiring of 3 wire, 2 wire GFCI or maybe driving another ground and doing 3 wire- why is that last one not a good solution?

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IN terms of modern wiring -- is not the ground wired up to copper rod jammed into the ground. Why not add an additional copper rod for a ground in the location of the house that needs 3 wire? I have one old room with 2 wire 90 feet from any box. The choice is $1000 worth of wiring of 3 wire, 2 wire GFCI or maybe driving another ground and doing 3 wire- why is that last one not a good solution?

While Charlie's answer is correct, it's not the main reason that your "solution" is wrong. The main purpose of a circuit grounding conductor is to reliably pass current from a short or ground fault back to the utility's grounded (neutral) feeder via the service panel and thereby allow the circuit's overcurrent device to function. A ground rod is not a reliable path for circuit ground fault current.

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IN terms of modern wiring -- is not the ground wired up to copper rod jammed into the ground. Why not add an additional copper rod for a ground in the location of the house that needs 3 wire? I have one old room with 2 wire 90 feet from any box. The choice is $1000 worth of wiring of 3 wire, 2 wire GFCI or maybe driving another ground and doing 3 wire- why is that last one not a good solution?

Ground rods are not needed, nor do they play any part to properly ground a receptacle. Ground rods are for high voltage events like lightning.

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Hmm COuld explain a lot of problems with this old house. 1 3 foot copper ground rod near main box, 2. Also tied into the copper plumbing under the house. I think i have to get this re-engineered.

Bear in mind that the ground rod has nothing whatsoever to do with the proper operation of the house's wiring system. It serves an entirely different function.

It sounds like you really need to have an electrician review your home's wiring.

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Hmm COuld explain a lot of problems with this old house. 1 3 foot copper ground rod near main box, 2. Also tied into the copper plumbing under the house. I think i have to get this re-engineered.

A 3' rod is not a recognized electrode. The rod type electrode needs to have 8' in direct earth contact.

Water line electrodes need to have 10' in direct earth contact.

The electrodes are for high voltage event like lightning.

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Kind of funny considering an electrician put it in and the city inspected it ..

What is the purpose of grounding to a copper pipe and a separate copper ground driven into the ground if i may ask ...

Well, I think you are allowing the size and type of cable you are seeing to confuse you. What you think is two grounds isn't two grounds at all. your system isn't "grounded" to the water pipe; it's grounded to the service grounding electrode which is the driven rod outside and it's bonded to the water piping in the home. Those are two entirely separate functions.

The service grounding electrodes - metal pipes buried in dirt and driven rods - are there to carry outside forces such as lightning to earth. The conductor between the driven rod and the panel is known as the "Service grounding electrode conductor." The connection to the piping inside the house via the bonding conductor is a permanent connection between conductive parts so that any objectionable fault current that's imposed on those parts can flow safely back to transformer via the neutral service conductor. Those are two entirely different flow paths with entirely different purposes.

It's easy to confuse the two; God knows, there are licensed electricians that are every bit as confused as non-electricians when it comes to understanding the two.

ONE TEAM - ONE FIGHT!!!

Mike

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Ok this makes sense and it may also account for the slight differential i am seeing- this old house has part galvanized and part copper - so the "grounding potentials" are different between the two metals. Epecially since the two types of metals are only bonded by a mechanical connection ( union or other joint)

Hmm Time for a revamp -

THanks for all the help

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