Need Excerpt from 1975 or earlier NEC - subpanel grounding

I am constantly, and I mean constantly finding subpanels in homes wired with 3 wire feed - meaning no 4th conductor - meaning neutral and ground are shared and bonded in the subpanel just like in a main service panel, and the subpanel is in the same building as the main panel. To my knowledge it was never acceptable to wire a subpanel in the same structure as the main panel without running both a grounded and a grounding conductor and keep them isolated. The only NEC allowed exception I am aware of is if its a separate structure not connected to the home in any metallic means, and it must have its own grounding electrode system (article 250).

My problem is perpetuated by a multitude of electricians that constantly claim these installations are “grandfathered” by the NEC. I don’t think any of them own an NEC handbook that goes back to these dates though… and neither do I.

So, I would absolutely love it if somebody on this forum happened to have an NEC code book from say, 1975 or earlier, and could possibly scan the page covering this topic and post it here. I would greatly appreciate it.

I have NEC books dating back to 1940 I’ll see what I can find. Also you can access older versions (pre-1920) from here:

Thanks Robert

I just ordered several old NEC codebooks from Amazon, they will be interesting to have around. I bought several for a penny each, plus $3.99 shipping. 1968, 1975, 1980’s. It’ll be a while before they arrive though.

I just did another Re-inspect of electrical repairs today, where the electrician said the lack of 4th wire grounding conductor to the sub panel in the ATTACHED garage is “grandfathered”. Probably the most abused and misused term in the industry. Same electrician used a nail to tie the breakers together on a 240 volt circuit, and the nail was long enough to catch the next breaker below them, so when you throw it, 3 breakers kick off. I told the client he can believe who he wants, but I’m not the one using non UL listed materials to tie breakers together, and I’m also the only one willing to put what I say in writing. I have yet to have an electrician SHOW me or a client where in any NEC book this has ever been acceptable. I should also mention that I too am an electrician, of the industrial variety, and I do everything by the book, because the book saves lives and equipment. If they don’t like following the code, then they need to find another job.

By chance are any of these panels fed by metallic conduit, just to rule that out? (The conduit itself is permitted as an EGC in the NEC)

But outside of conduit the blunt truth is this: up until the 80s (if not the internet of the 90s) this was by far the most common code violation. Around here every other sub panel is wired this way. It was never permitted, but the belief among electricians and DIYs was that it was perfectly legal. Further compounded by the fact inspectors thought the same failing to call it out along with the fact ranges and dryers were legally permitted to ground through the neutral which indirectly reinforced the notion (if it works for appliances hey it must work for sub panels). It was a common mistake perpetuated by myth, tradition and people never actually reading through a long boring book called the NEC. I don’t blame them lol.

As for the nail through the breaker I can’t see any legit electrician doing that, and if the 240 volt load has anything using 120 volts, per code that breaker must be internal common trip. I can’t think of any reason why an electrician would not stock 2 poles in their van.

Hey thanks Martin,
No there is no conduit but good question,
And I agree with you 100% on your whole paragraph, except maybe the part about not blaming them. Like I said earlier, if they don’t want to learn and perform their job properly then they need to find a different one. If you refuse to make a sandwich correctly at a fast food joint, you get fired. If you refuse to wire a house correctly, where people’s lives and appliances may be jeopardized, you should be fired too. Problem in Indiana is that there are NO state licensing requirements for electricians. It is left up to local municipalities. And most small town AHJ’s impose no license requirements. So anybody that knows how to use a screwdriver can open an electrical business and wire houses wrong, and the only one looking out for the people is people like me and you.

The NEC isn’t going to help you.

You would have printed proof that the install was incorrect.

Welcome, and no I do agree with you :slight_smile: Just because its done all the time does not make it right, and you should always read the laws you work with even if the system lets you not. One of the reasons I dedicate my time to giving away what little knowledge I have. I applaud you for doing the same.

Having a code book doesn’t mean anything. Obviously if you keep finding the same installation over and over and over again, it was allowed regardless of what you think is correct. I have looked at panels replaced this year, that the AHJ has allowed to be replaced and wired in this manner, simply because the panel replacement is classified as a repair.
I even called the building department after a couple were installed and they said it was acceptable.

I think any panel your reviewing that was installed in the 40’ 50’ 60’s has served its purpose to begin with, not having the 4th conductor would be a lesser concern.

Actually the NEC code book has already helped me in the two short days I have owned it, and it makes no sense why anybody would say it won’t.

It is simply my job to properly inform my clients of what is correct and incorrect, for their personal safety and the safety of their equipment that they plug in. It gave this client confidence and piece of mind knowing he had made the correct decision (to pay out of his own pocket for the correct feed to the garage sub panel), based on the facts I provided him, rather than the opinions of a sloppy electrician with nothing to back up his claims. A house built in 1975 is the most recent one in question here. The 1968 NEC code book I received in the mail two days ago states very bluntly with zero gray area that the grounded (neutral) conductor is without a doubt not allowed to be used as a grounding source after the service disconnect. This means that the most recent electrician in question that stated this installation was “grandfathered” is wrong, and I am right. As far as the AHJ goes, most rural counties in Indiana do not and never have required any permits or inspections, and the electric company only inspect from the meter base to the service disconnect and nothing there after. There is no AHJ deciding whether or not anything is right or wrong. But if an AHJ ever stated to me that these bogus installations were okay, and/or still are, I will look them in the eye and tell them they are wrong and that they should go into a different line of work. Nothing personal, just the facts here, and there’s nothing wrong with sharing facts.

Like I said earlier, the only one looking out for the client’s well being is me and people like me. Choose to be one, or choose not to be one, none of this is personal, just facts. Its so easy to learn the facts. Almost as easy as pulling a 4th freekin conductor. And I have pulled many… and I mean many.

The NEC helped me…:mrgreen:

You seem a little bit centered on proving yourself right and THEM wrong.

I write my report … Tell them what you saw and move on.

After that if the buyer chooses to believe the electrician, I could care less.

I applaud you! :mrgreen: I think all HIs should be like this, good job on getting that panel fed correctly.

In this case I think thats ok IMO. This was never code since day one, and if an electrician believes in something which clearly never was, one must ask what other incorrect information does he have or lack for that matter. Educating others wins; its key, rather than empower ignorance.

@Mr. Deakins, if found a PDF 1965 NEC:


I am centered on providing correct information. If the NEC ever permitted the neutral to be used as a grounding conductor then that is what I would report, but it never has and therefore that is what I will report. It is all quite simple. I (we) can be part of the solution, or part of the problem. When given the choice, I’ll take the high road every time.

There is a lot, and I mean a lot of small stuff that I do not sweat. I don’t write up every little annoying thing I can find, I’m not one of those guys. But safety is paramount and there is absolutely no excuse for any electrician to take shortcuts and bend the rules when it comes to life and equipment safety. I have zero tolerance for it. And lets not forget I am an electrician, and yes I hold myself to that same standard because I have no tolerance for hypocrisy either.

Today I am doing an installation of a 50hp 3 phase convertor for a rural sawmill because a new piece of equipment he wants to purchase is only available in 3 phase. I have scheduled a meeting with an engineer from the power company to help access the transformer requirements, and while I await his arrival I am reviewing the current NEC for the valuable information that I need to perform this installation correctly. Its all right there, just gotta read it. Its not hard to do the job right if you want to.

Thanks Martin and everybody, I appreciate all the feedback from anybody and everybody that takes the time out of their day to respond to a post.

Hey awesome link to the 1965 NEC, 250.61 word for word matches the 1968 version I have.

Any time, welcome and thank you for being part of the solution :slight_smile: