GFCIs in Place of Ungrounded Receptacles

[BMacky]

Has anyone ever run across any documentation (NEC, mfr's instructions, etc.) where GFCI's are recommended as suitable replacements for outlet locations where grounding is not present?

If there's no ground available, how can a GFCI function properly? I've read GFCI install instructions and have yet to see any recommendation there, yet home inspection reports often "suggest" the installation of GFCIs to offer additional protection in installations lacking an approved ground.

It makes sense that there would be some additional protection since I suppose the device would monitor changes on the ground side of a plugged-in piece of equipment, but the device itself should have an approved ground if installed per mfr's instructions.

Just looking for the missing data on the topic, if anyone can clue me in.

Thanks in advance.

 

[infinity]

The NEC allows the replacement to be a GFCI receptacle where no grounding means exists in the box. The GFCI device does not require an EGC to work.

406.4(D)(2) Non?Grounding-Type Receptacles. Where attachment
to an equipment grounding conductor does not exist in the
receptacle enclosure, the installation shall comply with
(D)(2)(a), (D)(2)(b), or (D)(2)(c).
(a) A non?grounding-type receptacle(s) shall be per-
mitted to be replaced with another non?grounding-type re-
ceptacle(s).
(b) A non?grounding-type receptacle(s) shall be per-
mitted to be replaced with a ground-fault circuit interrupter-
type of receptacle(s). These receptacles shall be marked
?No Equipment Ground.? An equipment grounding con-
ductor shall not be connected from the ground-fault circuit-
interrupter-type receptacle to any outlet supplied from the
ground-fault circuit-interrupter receptacle.
(c) A non?grounding-type receptacle(s) shall be per-
mitted 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.

 

[jumper]

IIRC the use of GFCIs as replacements was originally allowed because sometimes it was not a viable solution to get an EGC to the outlet.

A GFCI replacement is safer than a two prong receptacle in many situations, but a proper EGC is considered better by many people.

 

[jxofaltrds]

GFCIs in Place of Ungrounded Receptacles

Never have seen an "Ungrounded Receptacle"

 

[GoldDigger]

GFCIs in Place of Ungrounded Receptacles

Never have seen an "Ungrounded Receptacle"

OK. To make it consistent with other usage it should probably be an "Ungrounding Receptacle".

 

[jxofaltrds]

OK. To make it consistent with other usage it should probably be an "Ungrounding Receptacle".

I am being smart for a reason. The terms we use can be life or death.

Grounded (Grounding). Connected (connecting) to
ground or to a conductive body that extends the ground
connection.

Grounding Conductor, Equipment (EGC). The conductive
path(s) installed to connect normally non?current-carrying
metal parts of equipment together and to the system grounded
conductor or to the grounding electrode conductor, or both.

Receptacle. A receptacle is a contact device installed at the
outlet for the connection of an attachment plug. A single
receptacle is a single contact device with no other contact
device on the same yoke. A multiple receptacle is two or
more contact devices on the same yoke.

(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(C), grounding-type receptacles shall be used
and shall be connected to the equipment grounding conductor
in accordance with 406.4(C) or 250.130(C).

(2) Non?Grounding-Type Receptacles. Where attachment
to an equipment grounding conductor does not exist in the
receptacle enclosure, the installation shall comply with
(D)(2)(a), (D)(2)(b), or (D)(2)(c).

 

[ActionDave]

Has anyone ever run across any documentation (NEC, mfr's instructions, etc.) where GFCI's are recommended as suitable replacements for outlet locations where grounding is not present?

NEC 406.4

...I've read GFCI install instructions and have yet to see any recommendation there, yet home inspection reports often "suggest" the installation of GFCIs to offer additional protection in installations lacking an approved ground.

It makes sense that there would be some additional protection since I suppose the device would monitor changes on the ground side of a plugged-in piece of equipment, but the device itself should have an approved ground if installed per mfr's instructions.

Just looking for the missing data on the topic, if anyone can clue me in.

Thanks in advance.

All the GFCI packages I have opened have those stickers that say ?No
Equipment Ground.? so the manufactures must be on board.

 

[kwired]

Has anyone ever run across any documentation (NEC, mfr's instructions, etc.) where GFCI's are recommended as suitable replacements for outlet locations where grounding is not present?

If there's no ground available, how can a GFCI function properly? I've read GFCI install instructions and have yet to see any recommendation there, yet home inspection reports often "suggest" the installation of GFCIs to offer additional protection in installations lacking an approved ground.

It makes sense that there would be some additional protection since I suppose the device would monitor changes on the ground side of a plugged-in piece of equipment, but the device itself should have an approved ground if installed per mfr's instructions.

Just looking for the missing data on the topic, if anyone can clue me in.

Thanks in advance.

Understanding the basics of how a GFCI functions will make this easier to understand why it is permitted, and why protecting a receptacle with no EGC with a GFCI is a better option (I didn't say best option) then leaving it with no GFCI and no EGC.

A GFCI has a current transformer inside in which both protected conductors (all three for a two pole breaker including protected neutral) pass through. If the current going out on one conductor is equal to the current coming back on the other conductor the magnetic fields of those conductors cancel one another and the CT doesn't produce any output. If there is any current leakage in the circuit that doesn't return on the other circuit conductor there will be imbalance in the magnetic fields which will produce an output from the CT. This CT and the circuitry it drives is sensitive enough to detect a difference in the milliamp ranges and a class A GFCI is supposed to trip when the difference is in the 4-6 milliamp range.

The idea here is if 4-6 milliamps is passing through one conductor but not returning via the other - it is taking an unintended path - possibly through you.