Sub Panel Neutral/Ground Bond

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Little Bill

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What code year did the NEC require the grounding and grounded (neutral) to be isolated at a sub panel?

Reason I'm asking is I have to add another sub panel off of an existing sub panel and the neutrals and grounds are not separated. I didn't notice this on my walk through and didn't include straightening the old sub panel out in my price.
They did run a 4-wire feed to the sub but didn't isolate the neutral/grounds. I will of course isolate them in the new sub.

Would I be required to fix the old sub panel if it happens to have been required when it was installed?
 
What code year did the NEC require the grounding and grounded (neutral) to be isolated at a sub panel?

Reason I'm asking is I have to add another sub panel off of an existing sub panel and the neutrals and grounds are not separated. I didn't notice this on my walk through and didn't include straightening the old sub panel out in my price.
They did run a 4-wire feed to the sub but didn't isolate the neutral/grounds. I will of course isolate them in the new sub.

Would I be required to fix the old sub panel if it happens to have been required when it was installed?

You did not install it so you should not have too unless you will be paid for it,sell the idea to them::thumbsup:
 
Is this first subpanel at a detached structure, or within the same structure as the Service? I think it was 2008 that required feeders to detached buildings/structures to have separate grounded/grounding conductors.

Subpanels in the same building have (as far as I know) always been required to have separate grounded/grounding conductors if they were a grounded system, but this also might be the most common violation you see.
 
Is this first subpanel at a detached structure, or within the same structure as the Service? I think it was 2008 that required feeders to detached buildings/structures to have separate grounded/grounding conductors.

Subpanels in the same building have (as far as I know) always been required to have separate grounded/grounding conductors if they were a grounded system, but this also might be the most common violation you see.

It is at a detached building/shop.
 
If no grounding conductor had been run, then the old 3 wire feeders are grandfathered. Even so, a second panel in that detached building must have 4 wires from the first subpanel and ground/neutral separated in that second sub.

The strange thing here is that they ran 4 wires but wired it like they did three. As long as that 4th wire isn't grounded, and there are no other grounded metal paths between the main building and detached building, then it is permitted to keep neutral and ground connected like a Service (but only at the first "main disconnect" subpanel).
 
If no grounding conductor had been run, then the old 3 wire feeders are grandfathered. Even so, a second panel in that detached building must have 4 wires from the first subpanel and ground/neutral separated in that second sub.

The strange thing here is that they ran 4 wires but wired it like they did three. As long as that 4th wire isn't grounded, and there are no other grounded metal paths between the main building and detached building, then it is permitted to keep neutral and ground connected like a Service (but only at the first "main disconnect" subpanel).

The new/second sub panel is going to be remote from the house and the detached building.

Another strange thing I noticed today is that they landed the neutrals and grounds on the same bar but the bar is not bonded to the panel enclosure. They did use the 4th (egc) wire in both the main and sub.
So I got a mixture of "evils" here to deal with!:)

At the very least, along with wiring the new sub correctly, I will add a bonding screw to the first sub or some way of bonding it to the enclosure.
 
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I got a 1923, 1940 and a 1956(?) NEC, I will try and see if I can find a reference tomorrow.

Too lazy to search right now.:)

The change was in the 2008 NEC where they eliminated 250.32(B)(2) which appeared in the 2005 and earlier code editions and added an exception for existing installations in 250.32(B) of the 2008.
 
Bring it to the owners attention, explain why it needs to get redone, correct it and get paid for it.
 
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