# Two prong receptacles



## bhale7wv (Dec 30, 2014)

Gentleman. I would like to pick your collective brains, especially you old-timers, and do a little forensic work regarding two prong receptacles / receptacles without a ground.

In my locality, there were no Building / trade codes which were enforced statewide until 1972. Many of the larger cities had adopted their own codes prior to that, but these codes & their enforcement varied widely from location to location & in smaller localities there were no codes or enforcement at all. Then the state adopted a statewide code to be enforced everywhere in the state.

As you old-timers remember, most electrical work up until the late sixties involved the installation of either 2-wire NMC or 2-wire MC cable and installing 2 prong receptacles was the norm.

When the NEC (which most localities adopted & enforced) began requiring that 2 wire cable with a ground be used, we suddenly had 3 prong receptacles. As time went on and old 2-prong receptacles began wearing out or the bake-a-lite became brittle & breaking up, we often had to install 3 prong receptacles as the old two-prong ones became harder to find. (I remember selling the 2-prong at the hardware store where I worked after school in 1968.)

The NEC recognized this as a problem and began requiring that a separate ground (green) wire be run to each newly installed 3-prong receptacle.

I believe that this is the only instance where the code allowed you to run a separate conductor outside of the cable serving the device, and if this is incorrect, please correct me.

This continued to be the norm for years until the advent of GFCI protected circuits & receptacles. Once these hit the market, this allowed you to install one of these devices on the circuit feeding the receptacles, thus protecting the user from being shocked since the GFCI would trip when the short occurred.

OK, now for the question - is it true that in order to install a 3-prong receptacle in a box being feed from a 2-wire cable, one of the two methods noted above must be used.

YES or NO.

Thank you for your time.


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## cda (Dec 30, 2014)

not sure how old this is but look at

http://www.icgov.org/site/CMSv2/File/housing/genInfo/wiringAlts.pdf

nec 406.3(d)(3)

pictures but old:

http://ecmweb.com/code-basics/article-406-receptacles

and:: not sure how old

Receptacle replacement requirements

If you have a grounding means in the enclosure, use a grounding-type receptacle-even if you are replacing a nongrounding-type receptacle [4-6.3©]. Make sure you ground (bond) the grounding terminal of that receptacle.

If the enclosure doesn't have a grounding means-for example, if the box contains old 2-wire NM cable without a ground-you can use a nongrounding type receptacle (Figure 406-6). You have two other options, as well. You can use a GFCI receptacle if you make sure it's marked "No Equipment Ground." Or, you can use a grounding-type receptacle-if it's GFCI protected and marked "GFCI Protected" and "No Equipment Ground."

When you replace a receptacle in a location where GFCI protection is required, the replacement must be GFCI-protected. See 210.8 for GFCI protection requirements.

Here's a pop quiz. A relative asks you to replace a failed GFCI receptacle. But, you notice the home has a two-wire system-no ground wire. Will that GFCI provide ground fault protection?

Answer: Yes. GFCI protection functions properly on a 2-wire circuit without an equipment grounding conductor. The equipment grounding conductor serves no purpose in the operation of the GFCI protection device. The GFCI uses a small CT on the neutral and a small CT on the hot. There is no CT on the ground. Buy a new GFCI, and you will probably find this information in the enclosed instructions.

Does this mean that if you extend a circuit from an ungrounded box you can install a GFCI? No. Permission to replace nongrounding type receptacles with GFCI-protected grounding type receptacles does not apply to new outlets that extend from an existing ungrounded outlet box. Once you add a receptacle outlet (branch-circuit extension), the receptacle must be of the grounding type and be grounded per 250.130© (Figure 406-8).

This requirement may seem inconsistent, but it's not. Here's the logic. Your existing two-wire system was installed per the Code that existed at the time. Today's NEC does not mandate ripping out existing two-wire systems and replacing them just so you can add a GFCI. Nor does it allow you to add on to the two-wire system and just throw in a GFCI. A three-wire system is safer than a two-wire system. So, if you add to an existing system, what you add must be of the three-wire configuration-not the two-wire configuration.

http://www.mikeholt.com/mojonewsarchive/NEC-HTML/HTML/Article-406-Receptacles~20040628.php


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## ICE (Dec 30, 2014)

Whatever you do when replacing a receptacle, it will require ARC fault protection.


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## Rick18071 (Dec 30, 2014)

Ice, I don't agree. The NEC only requres branch circuits to be protected by ARC fault protection not receptacles or outlets. So you only need ARC fault for a new circuit, not a new receptacle.


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## mark handler (Dec 30, 2014)

http://www.thebuildingcodeforum.com/forum/residential-electrical-codes/12461-grounded-receptacle-2-wire-system.html


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## Francis Vineyard (Dec 31, 2014)

bhale7wv said:
			
		

> The NEC recognized this as a problem and began requiring that a separate ground (green) wire be run to each newly installed 3-prong receptacle.
> 
> I believe that this is the only instance where the code allowed you to run a separate conductor outside of the cable serving the device, and if this is incorrect, please correct me.
> 
> ...


Yes, a separate EGC wire to my knowledge was allowed in the 1996 NEC ARTICLE 250-50(b) and the following from the 2011 NEC;

250.130 Equipment Grounding Conductor Connections.

© Nongrounding Receptacle Replacement or Branch

Circuit Extensions. The equipment grounding conductor

of a grounding-type receptacle or a branch-circuit extension

shall be permitted to be connected to any of the following:

(1) Any accessible point on the grounding electrode system

as described in 250.50

(2) Any accessible point on the grounding electrode conductor

(3) The equipment grounding terminal bar within the enclosure

where the branch circuit for the receptacle or

branch circuit originates

(4) For grounded systems, the grounded service conductor

within the service equipment enclosure

(5) For ungrounded systems, the grounding terminal bar

within the service equipment enclosure

Informational Note: See 406.4(D) for the use of a groundfault

circuit-interrupting type of receptacle.


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## Francis Vineyard (Dec 31, 2014)

Also see 250.134(B) exception 1. _As provide in 250.130©, the equipment grounding conductor shall be permitted to be run separately from the circuit conductors._


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## Span (Dec 31, 2014)

Agree w/Rick, also AFCI only req'd for extended portion from existing, and 250.130 the grounding wire shall connected at panel or grounding system but most of electrician just bond it at near by water line.


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## ICE (Dec 31, 2014)

> 406.4 (D)(4) requires a replacement receptacle to be AFCI where required elsewhere in the NEC.


I don't have a code book with me so I copied this from the MH forum.  Now that guy is from Washington state so perhaps I am wrong...it happens.

This is one guy's answer to the problem.  There is a receptacle on the other side of the wall.  His computer is served by that receptacle and he wasn't taking any chances.


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## Pcinspector1 (Jan 1, 2015)

I believe you can protect a circuit with several two prong recepticles with one GFCI recepticle or breaker without having to replace any of the two prong recepticles.

Pc1


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## manchesterspark (Jan 19, 2015)

Rick18071 said:
			
		

> Ice, I don't agree. The NEC only requres branch circuits to be protected by ARC fault protection not receptacles or outlets. So you only need ARC fault for a new circuit, not a new receptacle.





			
				Span said:
			
		

> Agree w/Rick, also AFCI only req'd for extended portion from existing,


Cut and Pasted from the 2011 NEC  ( Under lining by me)

Section 406

(D) Replacements. Replacement of receptacles shall comply with 406.4(D)(1) through (D)(6), as applicable.

406.4 (D)(4)

(4) Arc-Fault Circuit-Interrupter Protection.Where a receptacle outlet is supplied by a branch circuit that requires arc-fault circuit interrupter protection as specified elsewhere in this Code, a replacement receptacle at this outlet shall be one of the following:

(1) A listed outlet branch circuit type arc-fault circuit interrupter receptacle

(2) A receptacle protected by a listed outlet branch circuit type arc-fault circuit interrupter type receptacle

(3) A receptacle protected by a listed combination type arc-fault circuit interrupter type circuit breaker

This requirement becomes effective January 1, 2014.

If your Jurisdiction has adopted the 2011 NEC ---- As of January 1 ,2014  If you replace a receptacle in an area the would be required to have AFCI protection , you must provide the AFCI protection for that Receptacle. This can be done by using an AFCI circuit breaker, a AFCI receptacle , or by having the receptacle fed from from ( and protected by )  an AFCI receptacle.


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## Pcinspector1 (Jan 20, 2015)

Is'nt the requirement of NEC 406.4 (d)(4) and the IRC requirement R105.2 Work exempt from permit, Electrical (5) a conflict with the TWO codes??

Do you tell the homeowner doing his own work he needs to meet the NEC requirement?

Has any AHJ's omitted the AFCI'S

Just asking?


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## bhale7wv (Jan 22, 2015)

Pcinspector1 said:
			
		

> Is'nt the requirement of NEC 406.4 (d)(4) and the IRC requirement R105.2 Work exempt from permit, Electrical (5) a conflict with the TWO codes?? Do you tell the homeowner doing his own work he needs to meet the NEC requirement?
> 
> Has any AHJ's omitted the AFCI'S
> 
> Just asking?


The homeowner can only replace the receptacles in kind without a permit - remove a 2 prong receptacle & replace with a new 2 prong receptacle.

If they replace it with a 3 prong receptacle, the permit is required.


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