No ground in wiring system - metal boxes.

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bjp_ne_elec

Senior Member
Location
Southern NH
Guess I've been spoiled, as the only knob and tube I've seen so far was in my father's house. Just ran in to a house that is wired with Romex - but it's the older stuff with the undersized ground. I found some newer Romex, but as I was walking through doing an estimate, I plugged my circuit checker plug (that's what I call it - but it's the three light plug in) and immediately noted that the Open Ground light, that should be brightly lit, was lit but very dim. This was a three prong plug, and I flagged the owner that this particular receptacle definitely needs to be dealt with, due to the open ground. The feed was defiinitely the older Romex with the smaller ground.

This smaller ground - have heard it referred to as "static ground" by an old-timer - was that an accepted ground back when this was installed? The owner, not the original, and not the one who had the newer Romex installed said he knows for a fact that the house was built in 1954. I've heard guys say they've found this type of installation where this smaller ground didn't get made up consistently thorughout the installation. Again, one of my main questions is, was this supposed to be required to be made up, complete through all circuits, back to the panel? Did the code back in 1854 consider this an acceptable ground, due to the undersized bare wire - it appears to be about 16 or 18 AWG?

My question is, as I'm not familar with knob and tube - and that's what I'm likening this situation to - is there a way to legitimately install metal boxes, etc.? You obviously won't have a bonded ground in the system, unless you go and run new HR's for any circuits that are modified. There are metal boxes installed in the garage and in a screened porch, and my concern is how do you assure they are properly grounded - considering this undersized bare copper wire?
 
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Jim W in Tampa

Senior Member
Location
Tampa Florida
This is nothing like K&T.What you have is still romex.That thin ground often will be melted or broken.My guess is they were trying to save copper from the war days.Take it one box at a time and good luck.
 

bjp_ne_elec

Senior Member
Location
Southern NH
JimW - is this acceptable, in the event of a "new repair", as a ground? What I mean here, is if I were to change out a switch, that I found in a metal box - would this be passed by an inspector using the 2005 NEC?

Brett
 

Jim W in Tampa

Senior Member
Location
Tampa Florida
If all you are doing is replacing a device i think your ok.There are plenty of ungrounded steel boxes from the days of k&t and no ground romex.You do not need to meet 05 code
 

jeff43222

Senior Member
Make sure you test your tester.

I ran into a job the other day where the housing inspector flagged a couple of receptacles as open ground. I plugged in my tester, and, sure enough, got the same reading. So I opened up the boxes and found new Romex with everything connected nice and tight. As long as I was there, I tested a few other receptacles, and they all showed open grounds, too. So I got another tester out of the truck, and it showed everything as OK. When I got home, I put the first tester into some receptacles, and it showed an open neutral, which I'm certain couldn't be true. The tester worked fine the next day.
 

don_resqcapt19

Moderator
Staff member
Location
Illinois
Occupation
retired electrician
The EGC in NM, if there even was one, was 1 to 2 sizes smaller than the circuit conductors until sometime in the late 60's or early 70's.
Don
 

cpal

Senior Member
Location
MA
don_resqcapt19 said:
The EGC in NM, if there even was one, was 1 to 2 sizes smaller than the circuit conductors until sometime in the late 60's or early 70's.
Don

As Don Stated

I believe the 16ga EGC (bond) was increased to a full size with the 68 or 71 NEC (I'm pretty sure 71).
The reduced EGC was reconized as such and used this was when the three wire receptacles appeared(with the full size ground). I agree that circuit extensions from this product is questionable. but the existing wiring was acceptable.

Charlie
 

allenwayne

Senior Member
jeff43222 said:
Make sure you test your tester.

I ran into a job the other day where the housing inspector flagged a couple of receptacles as open ground. I plugged in my tester, and, sure enough, got the same reading. So I opened up the boxes and found new Romex with everything connected nice and tight. As long as I was there, I tested a few other receptacles, and they all showed open grounds, too. So I got another tester out of the truck, and it showed everything as OK. When I got home, I put the first tester into some receptacles, and it showed an open neutral, which I'm certain couldn't be true. The tester worked fine the next day.
Jeff depending on the plug tester you are using an open / or a weak connection on a neiutral will read an open ground on the tester.I always have my fluke with me and when I find a receptacle that reads open ground I use it to determine what is really the problem.
 

al hildenbrand

Senior Member
Location
Minnesota
Occupation
Electrical Contractor, Electrical Consultant, Electrical Engineer
bjp_ne_elec said:
This smaller ground - have heard it referred to as "static ground" by an old-timer - was that an accepted ground back when this was installed? The owner, not the original, and not the one who had the newer Romex installed said he knows for a fact that the house was built in 1954. I've heard guys say they've found this type of installation where this smaller ground didn't get made up consistently throughout the installation. Again, one of my main questions is, was this supposed to be required to be made up, complete through all circuits, back to the panel? Did the code back in 1854 consider this an acceptable ground, due to the undersized bare wire - it appears to be about 16 or 18 AWG?
I installed this as an apprentice in the late '60s. I was taught to twist the wires together (no pressure connector or wire nut) and connect one long one to the receptacle ground.

What I was taught was accepted by an AHJ as a "reasonable compromise" from what the NEC spelled out and what he could get his stable of electrical contractors to believe had to be enforced.

In the 1959 NEC, grounding type receptacles were required only in certain installations. Think window AC. Two wire, non-grounding receptacles were commonly installed in dwellings, even when the wiring method was, in fact, grounded.

Then, the 1962 NEC made the leap and all receptacles had to be grounding type. The passage (1962 NEC 250.114) governing bonding at metal boxes was rewritten to describe ground screw and/or ground clip connection of the EGC.

Prior to the 1962 NEC going into effect, NM cable had been available with an EGC but was rarely purchased by residential contractors. After 1962, the EGC became readily available in NM, but as a "reduced Gage" EGC. The 1962 NEC described how to hook up the EGC, essentially as it is today, and identified the reduced Gage EGC as a grounding means, but the actual installation of the EGC, as we think of it now, was not uniformly enforced.

BJP,

For your 1954 job, all bets are off as to how the EGC is run, as the important changes in the NEC came eight years later.

If you can string the reduced Gage EGC together, it was an acceptable EGC.
 
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infinity

Moderator
Staff member
Location
New Jersey
Occupation
Journeyman Electrician
My house built in the 1960's had NM cable with the reduced size EGC. The terminations were rather strange. The EGC's were threaded through a hole in the back of the box, twisted together and a fork stakon was crimped on. The stakon was terminated on one of the screws on the outside of the box. Better than nothing I guess. Unless you needed to get at the connection.
 

al hildenbrand

Senior Member
Location
Minnesota
Occupation
Electrical Contractor, Electrical Consultant, Electrical Engineer
infinity said:
The EGC's were threaded through a hole in the back of the box, twisted together and a fork stakon was crimped on. The stakon was terminated on one of the screws on the outside of the box.
That's impressive.

I can only imagine the thought process that went into the solution. I imagine a "messyness that all those bare wires cause" leading an installer to try to keep them out of the way.
 

pete m.

Senior Member
Location
Ohio
Are there any statistics that might show that this "reduced" EGC could cause a fire hazard under a ground fault condition. Simply due to it's reduced size when compared to the ungrounded conductor?

Thanks, Pete
 

Jim W in Tampa

Senior Member
Location
Tampa Florida
pete m. said:
Are there any statistics that might show that this "reduced" EGC could cause a fire hazard under a ground fault condition. Simply due to it's reduced size when compared to the ungrounded conductor?

Thanks, Pete
More likely a shock hazard if they burn open after a few hard shorts
 

LarryFine

Master Electrician Electric Contractor Richmond VA
Location
Henrico County, VA
Occupation
Electrical Contractor
bjp_ne_elec said:
This smaller ground - have heard it referred to as "static ground" by an old-timer - was that an accepted ground back when this was installed?
Absolutely.
Again, one of my main questions is, was this supposed to be required to be made up, complete through all circuits, back to the panel?
Yes.
Did the code back in 1854 consider this an acceptable ground, due to the undersized bare wire - it appears to be about 16 or 18 AWG?
Yes again. It was originally done for bonding. I have remodeled plenty of homes where the reduced-size ground was only run from the panel to boxes in the kitchen, bath, etc., and the rest of the circuit was run with NM with no grounding conductor at all.
My question is, as I'm not familar with knob and tube - and that's what I'm likening this situation to - is there a way to legitimately install metal boxes, etc.?
Now or then? At the time, there was no grounding requirement for device boxes. Now, there is.
There are metal boxes installed in the garage and in a screened porch, and my concern is how do you assure they are properly grounded - considering this undersized bare copper wire?
It's legal now, as long as it was in compliance at the time it was done.

I would suggest tracing the entire circuit and making grounding connections as you would now, bonding the box, just using the wire in the cable, and adding pigtails to grounding receptacles.

If you really need a full-size ground for a particular load, I'd recommend running a new circuit using modern methods.
 
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bjp_ne_elec

Senior Member
Location
Southern NH
Yeah - it seems like every box I opened up this reduced size EGC was done differently. Some where simply twisted together and stuffed back in. Others were twisted together, and then with one wire left long, it was wrapped around a 6/32 in one case, and on and on.

So, strictly living under the jurisdiction of the 2005 NEC, how would a circuit extension be treated. Do you just leave the grounds of the new NM pushed back in, should you bond them to the metal box, do you twist them all together and not bond to the box (the thing I'm concerned about, if someone was to open this scenario, they might get the impression - "hey this one's grounded). It's really doesn't seem clear from the various reponses that we can get a majority!

Keepin' the juices flowin' - or is that neurons!

Brett
 

LarryFine

Master Electrician Electric Contractor Richmond VA
Location
Henrico County, VA
Occupation
Electrical Contractor
bjp_ne_elec said:
So, strictly living under the jurisdiction of the 2005 NEC, how would a circuit extension be treated. Do you just leave the grounds of the new NM pushed back in, should you bond them to the metal box, do you twist them all together and not bond to the box (the thing I'm concerned about, if someone was to open this scenario, they might get the impression - "hey this one's grounded). It's really doesn't seem clear from the various reponses that we can get a majority!
I would do what code calls for today, and what the reduced-size wire was for: bonding the box. When this wire was added to certain home runs, such as bath and kitchen circuits (both receptacles and switches, by the way), grounding receptacles were not yet required.

If you have a grounding receptacle, add the pigtail I mentioned earlier, either using the same wire if it's long enough, or add a second pigtail to the bundle, and use crimp ferrules or wirenuts.
 

LarryFine

Master Electrician Electric Contractor Richmond VA
Location
Henrico County, VA
Occupation
Electrical Contractor
neal said:
I would like to post a new topic. How do I do it?
When you click on a topic forum, there's a button above "Threads in Forum" in the top-left corner, with the words "New Topic or Question" on it. Click away.
 

LarryFine

Master Electrician Electric Contractor Richmond VA
Location
Henrico County, VA
Occupation
Electrical Contractor
memyselfandI said:
Anybody ever consider replacing the receptacle with a GFCI type and identify it with a sticker that says " No Equipment Ground"? Isn't this code compliant?
Hey, fellow Virginian! Yes, and yes. The original question was about dealing with what he found, so that's where we went. I wouldn't call the reduced-size wire "No Equipment Ground".
 
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