residential service inspections-grounding

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Michael Abruzzi

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Arvada Colorado
Friends,

I'm an electrical inspector in colorado and have a grounding question regarding service upgrade inspection.

An electrical contractor obtains a permit to change out a residential electrical service. Bonding and grounding are correct at the service power panel however the E.C does not float the neutrals at the down stream sub- panels.

These sub-panels are protected by a main breaker in the service power panel; and are not modified during the upgrade.

This is a two-part question: First I argue that the E.C must float the neutral at the sub-panel, even if it has not been modified and not listed on the electrical permit as part of the scope of the job. secondly, on an older sub-panel with an uninsulated neutral as part of the feeder assembly(3-wires ystem), has the code ever allowed equipment grounds to be terminated on the neutral bar in this type of wiring system?
The answer to this question will resolve a disagreement.
 
Michael Abruzzi said:
First I argue that the E.C must float the neutral at the sub-panel, even if it has not been modified and not listed on the electrical permit as part of the scope of the job.
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The so-called ?Grandfather Clause? has been moved to the non-enforceable annex. Take a look at 80.9(B). If you think the existing situation creates an ?imminent danger to occupants,? and by the way I do, then you can require it to be corrected. I would say that it is not the fault of the EC, and the homeowner should not expect the EC to do the job at no cost. But I think it should be done.


Michael Abruzzi said:
Secondly, on an older sub-panel with an uninsulated neutral as part of the feeder assembly(3-wires system), has the code ever allowed equipment grounds to be terminated on the neutral bar in this type of wiring system?
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I am not certain. But if I correctly understand post #3 from the following thread, it has not been allowed since 1918.
http://forums.mikeholt.com/showthread.php?t=130875

Welcome to the forum.
 
Does your area have something like this in the building code?

"115.4 Additions and alterations.

Additions or alterations to residential buildings shall conform to the requirements of the code for new construction and shall be approved by the residential building official. Additions or alterations shall not be made to an existing building or structure which will cause the existing building or structure to be in violation of any provisions of this code. Except as otherwise provided for in Section R313.1.1, portions of the structure not altered and not affected by the alteration are not required to comply with the code requirements for a new structure."

My comment: R313.1.1 covers smoke detectors and is not part of your electrical question.

"115.5 Alterations to systems, components and materials.

Alterations to an existing system (egress, fire protection, mechanical, plumbing, etc.) and materials or building components not otherwise provided for in this section shall conform to that required for new construction to the extent of the alteration. The existing systems, materials or components shall not be required to comply with all of the requirements of this code for new construction except to the extent that they are affected by the alteration. Additions or alterations to existing systems materials or components shall not cause them to become unsafe, hazardous, overloaded or become less effective than when originally installed, constructed and/or approved."

I say that the 'subs' are affected. This is a service upgrade and to me that includes the service equipment Article 100.
 
K8MHZ said:
Been there, done that.

Even though both the inspector and I grimaced at all the improperly bonded sub panels on a site we did a service upgrade on, we couldn't force the customer to change them.
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Would you allow them to put two grounded conductors under a lug if they showed you a picture of the panel before the upgrade having them?

I say again the 'sub' must be addressed.
 
jxofaltrds said:
Would you allow them to put two grounded conductors under a lug if they showed you a picture of the panel before the upgrade having them?

I say again the 'sub' must be addressed.
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That's what I thought, too, but that's not how it worked.

Oh, and the panels in question weren't part of the job. They weren't even in the same room, I just happen to notice that they were incorrect because someone had left the covers off them.

The inspector just said that the covers had to be put back on and that he had no authority to make the customer change the sub panels.
 
K8MHZ said:
That's what I thought, too, but that's not how it worked.

Oh, and the panels in question weren't part of the job. They weren't even in the same room, I just happen to notice that they were incorrect because someone had left the covers off them.

The inspector just said that the covers had to be put back on and that he had no authority to make the customer change the sub panels.
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I understand what you are saying.

You do not have to look at the 'subs' to know that they are not wired properly or did he not inspect the inside of the 'new' panel?
 
jxofaltrds said:
I say that the 'subs' are affected. This is a service upgrade and to me that includes the service equipment Article 100.
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The sub panels are not service equipment so it is not service upgrade. I think many areas will allow this install. Personally I would never leave the subpanel with no egc.

We can argue all day on this but it comes down to the AHJ. You & the OP are the AHJ so make the call.

This issue comes up alot as well as the AFCI being required with an upgrade. 2011 makes it clear that it is not necessary however there are many jurisdictions that req. it.
 
Dennis Alwon said:
The sub panels are not service equipment so it is not service upgrade. I think many areas will allow this install. Personally I would never leave the subpanel with no egc.

We can argue all day on this but it comes down to the AHJ. You & the OP are the AHJ so make the call.

This issue comes up alot as well as the AFCI being required with an upgrade. 2011 makes it clear that it is not necessary however there are many jurisdictions that req. it.
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Dennis you are correct as to the subpanel.

I am wondering how you connect it to the new panel.
 
jxofaltrds said:
Dennis you are correct as to the subpanel.

I am wondering how you connect it to the new panel.
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well with service cable I have seen it installed just as it was before. It was connected to both the service panel and sub panels neutral bar. There was no separate ground bar in the sub panel.
 
Dennis Alwon said:
well with service cable I have seen it installed just as it was before. It was connected to both the service panel and sub panels neutral bar. There was no separate ground bar in the sub panel.
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So connecting a safety violation is allowed? So my above example concerning the grounded conductors would be OK also?
 
jxofaltrds said:
So connecting a safety violation is allowed? So my above example concerning the grounded conductors would be OK also?
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Mike I don't condone it. The same issue is there even if you wired a new feeder with an egc when the dryer and range are still connect with seu cable.
 
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