As some may know, I'm writing a lesson on K&T wiring, because I am sick of explaining it....

Anyway, in the course of doing so I came upon a code that I have debated to my advantage a few times, and lost a few times... (interpritation/general additude of AHJ wise)

Posting to get some feed-back from what I often refer to as "The Wider Electrical World", you guys.....

Code in question is:


For instance you have a customer who wants to have non-grounded, K&T fed devices match the rest of thier whimical design of having hot pink decora duplex recepticals...

Could you not take the entire 2-wire circuit and put it on a a GFCI breaker, or even a AFCI breaker with class A GFI protection? Provided you marked every outlet with “GFCI Protected” and “No Equipment Ground.”

IMO yes you could.

That however will not allow the homeowner to use equipment that needs grounding without a 250.114 violation.

Bob

Iwire nailed it.
A big however, make very certain that the owner knows that computers and their surge protectors will NOT be safe on an ungrounded circuit.
I see this on rewires all the time and advise the electrician to sell up the job with a dedicated circuit for the home computer and entertainment areas.
Alan--

Bob, Alan, VERY good points indeed....


In my little (now 14 page doc) I suggest areas in which items like that would be used AND "home offices" not have K&T to remain anyway, but will add refferance to these concerns....

It is my undersanding that if a jurisdiction is under the IRC you can not substitute GFCI protection for grounding. If you are to replace a 2 wire receptacle with a receptacle that has is 2 wire with ground you must install an EGC back to the panel.

I copied this information out of the IRC - I didn't have it available when I posted the prior comment.

[This message has been edited by George Little (edited 05-22-2006).]

Is there any language about how the grounding conductor is run?

There aren't any specific instructions in the IRC for running this grounding conductor other than running it in a raceway or cable that I can find. I looked in the '02 NEC and there aren't any guidelines in there either. I seem to remember wording about running a single conductor (not in a racewaay or cable) to the water service or panel as long as it was physically protected. Maybe it's gone now.

The point I was trying to make was that the NEC allows the use of GFCI protection in lieu of grounding in some cases but the IRC doesn't allow this approach.

[This message has been edited by George Little (edited 05-22-2006).]

It seems the IRC is simular to the former interpetations of the NEC, in 406.3 D(1), you are reffered to 250.130(C), and you would find....

Which was fine untill the code changed in '93 to no more than 5' from entrance of building.....

And this interpetation resulted...
"Because of the requirements of 250.52(A)(1), an interior metal water pipe more than 5 ft from the point of entrance of the water pipe into the building is no longer allowed to serve as a connection to the grounding electrode conductor."

So back in the day it was easy, just ground to any portion of the cold water... DONE!

But what does it say in these sections?
"as allowed and described in Chapters 33 through 42."

The two codes may revert to apple / apple again.

I think Greg's question had to do with how you physically connected the EGC to the Grounding Electrode System and I did find what I was looking for in the NEC at 250.120(C). If I'm reading it correctly you could run an open wire sized smaller than #6 to the Grounding Electrode System etc and not have it in a raceway or cable as long as it was physically protected. You could run a #14 bare or green from the receptacle you would be installing, to the water service (within 5 feet) or to the panel. It would not have to be in a raceway. Does everyone agree?

I know what the code says but I have never really been sure what it means. I have never been around an ungrounded building. I think it was the GI bill housing requirements or something but every house I saw in the DC area used <small EGC> grounded Romex, even before they had 3 prong receptacles (post war). Houses older than that were wired in BX. I have never seen K&T either.
The old buildings I saw as Fla state inspector were wired in pipe or some kind of armored cable. I thought I might see some K&T at the 1926 Ringling mansion in Sarasota but it was EMT or rigid everywhere. No galvanizing though, all black painted. There was some "new" work in BX/AC but nothing NM. All of the renovations used EMT or MC.

Greg- You've led a sheltered life ( NM cable wise), come to Michigan and I'll show you all the NM cable you can stand that doesn't have am EGC run with it.

I was always told that a post war house needed a grounded wiring method to pass GI Bill inspection. That may not have trickled down to the hinterlands but it was true in DC. I know as late as 1971, you couldn't get a GI loan on an "aluminum" house.

All right Greg- What's the "Hinterlands"?

[This message has been edited by George Little (edited 05-23-2006).]

Outside the Beltway


[This message has been edited by gfretwell (edited 05-23-2006).]

Okay Greg- But we do have indoor plumbing. (I owe you one Greg)

George, I am unable to find that particular code section in the MRC. Could you give me that number?

The code reference is in the 2003 MRC (Michigan Recidential Code) is on page 557. This puts in the Appendix J on Existing Buildings. I don't want anyone giving me a ration of s**t about the Appendix not being part of the code either. There is nothing in the MRC or the IRC (International Residential Code) that allows the use of GFCI protection in lieu of grounding. To my knowledge the appendix is allowable for code compliance in the State of Michigan. Of course I've been wrong before