Gfci

Does there have to be a grounded conductor present in order to have a GFCI work properly? This house is wired with just hot and neutral, no ground. There is a GFCI outlet in bathroom that tested ok. Just curious.

It must be marked that it is not grounded, but it can still work as intended without a ground. See NEC, 406.3(D)(3)(b). The GFCI’s internal electronic circuitry actually provides a better level of shock protection than the ground.

Gary,
A simple explanation for reports CPSC

Yes, the ***grounded ***conductor is the neutral conductor. A grounding conductor is not required. Okay, I knew what you meant. :stuck_out_tongue:

A GFCI protection device operates on the principle of monitoring the imbalanced current between the ungrounded (hot) and grounded (neutral) conductors. In a typical 2-wire circuit, the current in amperes returning to the power supply will be the same as the current leaving the power supply (except for small leakage). If the difference between the current leaving and returning through the current transformer of the GFCI protection device is 5 milliamperes (+ or – 1 milliampere), the solid-state circuitry activates the shunt trip feature to open the switching contacts of the GFCI, thereby de-energizing the circuit.

From: http://www.mikeholt.com/mojonewsarchive/All-HTML/HTML/GFCI-Receptacles-Without-Ground~19991230.php

How was it tested?

Thanks Larry, I meant grounding conductor.

You mean Equipment Grounding Conductor right Gary…:wink:

So, reading the CPSC article, we should recommend replacing old 2 wire outlets with either new tight 2 prongs, or 3 prongs GROUNDED or GFCI’s? So it is ok to put a GFCI in a living room? I know it is ok but is that a ok fix? I know they have AFCI’s also. I usually tell them to use a good Surge protector if they keep the 2 wire and are plugging in large things like tv’s, computers or things in that nature.
Thanks

Andy,

I am not sure about the surge protection statement but I will say it is perfectly fine to have a GFCI in the living room or where ever you would like to have it as nothing prohibits the use of GFCI’s on 15 and 20A branch circuits…and in fact if you have AFCI at the panel and GFCI at the first receptacle then well you can have the best of both worlds…honestly it is safer technically speaking than leaving it an old 2-wire setup with no protection at all.

Just remember their are other requirements to putting 3 prong plugs on old 2-wire systems…once all the provisions are met it is fine.

Paul, what are those requirements, I’m assuming proper grounding. What ways can that be accomplished?

(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 a grounding
conductor is installed in accordance with 250.130©,
grounding-type receptacles shall be used and shall be
connected to the 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 grounding
means 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
interrupter type
of receptacle(s). These receptacles shall be marked
“No Equipment Ground.” An equipment grounding conductor
shall not be connected from the ground-fault circuit interrupter-
type receptacle to any outlet supplied from the
ground-fault circuit-interrupter receptacle.
© A non–grounding-type receptacle(s) shall be permitted
to be replaced with a grounding-type receptacle(s)
where supplied through a ground-fault circuit interrupter.
Grounding-type receptacles supplied through the ground fault
circuit interrupter shall be marked “GFCI Protected”
and “No Equipment Ground.” An equipment grounding
conductor shall not be connected between the grounding type
receptacles.

Thanks Paul and All