subpanel from another subpanel when neutrals where not required to be isolated

[Stevenfyeager]

Years ago, subpanels were not required to isolate the neurtal from the ground. A customer has an older home (1980s) and apparently subpanels were not required to have neutrals isolated. One subpanel (with neutrals and grounds together) feeds another subpanel (same). I had to relocate the second sub, and I separated the two bus bars. Should I have done that? Should I 'correct' the first subpanel too? Its a 400 amp house, and has a third sub. from another main panel. Should I 'correct' it too? Usually existing conditions aren't required to be changed, but since I had to relocate the one panel, did I do right by separating the grounds and neutrals, even though its source panel is not separated? Thanks

 

[ActionDave]

It's never been allowed to re bond the neutral at a sub panel in the same building, it was allowed at separate structures until 2005 code.

 

[Little Bill]

That's not exactly true about subpanels not having to have the gnds/neutrals separated. If the subpanel was in the same building, the gnds/neutrals had to be separate. It did use to be allowed to keep them bonded in a separate building with exceptions such as no metallic path between the buildings.

To answer your questions, you did right in separating them in the panel you moved. If the other subs are in the same building they should have been separated. It's not your responsibility to correct the others unless you're moving them, but if the customer agrees to pay for it, you could correct the others as well.

ETA: Oops, I was typing when Action posted!

 

[roger]

Years ago, subpanels were not required to isolate the neurtal from the ground. A customer has an older home (1980s) and apparently subpanels were not required to have neutrals isolated.

They were required to be isolated (separated) in the 80's, you need to invest in some older code books to help you with older installations.

Roger

 

[packersparky]

They were required to be isolated (separated) in the 80's, you need to invest in some older code books to help you with older installations.

Roger

From my research, it was never allowed to make a connection between the EGC and the grounded conductor if the panel was in the same building. My research goes back to the 1920's.

 

[mbrooke]

But to be fair to the OP, this was very common in some areas despite never being allowed. Plenty of apartments here have 3 wire feeds to the tenant panels.

 

[packersparky]

But to be fair to the OP, this was very common in some areas despite never being allowed. Plenty of apartments here have 3 wire feeds to the tenant panels.

It may have been common, but it has not been allowed for many, many years.

 

[packersparky]

Years ago, subpanels were not required to isolate the neurtal from the ground. A customer has an older home (1980s) and apparently subpanels were not required to have neutrals isolated. One subpanel (with neutrals and grounds together) feeds another subpanel (same). I had to relocate the second sub, and I separated the two bus bars. Should I have done that? Should I 'correct' the first subpanel too? Its a 400 amp house, and has a third sub. from another main panel. Should I 'correct' it too? Usually existing conditions aren't required to be changed, but since I had to relocate the one panel, did I do right by separating the grounds and neutrals, even though its source panel is not separated? Thanks

3 wire or 4 wire SE(R) cable?
If you moved the second subpanel and it did not have an equipment grounding conductor, you created a dangerous situation. If the panel has an equipment grounding conductor, it is fine.

 

[mbrooke]

It may have been common, but it has not been allowed for many, many years.

Thats true, but be prepared to see it every other day in the field.

 

[packersparky]

Thats true, but be prepared to see it every other day in the field.

I don't have to prepare myself. I have seen it, and have told homeowners it needs to be corrected.

 

[Stevenfyeager]

3 wire or 4 wire SE(R) cable?
If you moved the second subpanel and it did not have an equipment grounding conductor, you created a dangerous situation. If the panel has an equipment grounding conductor, it is fine.

All 3 subpanels in the house have 4 wire SER cables run to them. Thanks

 

[Sierrasparky]

All 3 subpanels in the house have 4 wire SER cables run to them. Thanks

They may have been bonded by mistake or the EC did not order ground bars , I still see it done today.

I would get the owner to pay to separate is sounds pretty easy.

 

[Stevenfyeager]

They may have been bonded by mistake or the EC did not order ground bars , I still see it done today.

I would get the owner to pay to separate is sounds pretty easy.

I think I am slowly remembering....it may be I was remembering separate buildings. In the early 90s, all the inspectors around here had us run 3 wires to a detached blg subpanel and drive a ground rod. Then somewhere in those years afterwards, they all changed to requiring 4 wires and a ground rod. So maybe what I was thinking of was separate buildings. Thanks

 

[mbrooke]

I think I am slowly remembering....it may be I was remembering separate buildings. In the early 90s, all the inspectors around here had us run 3 wires to a detached blg subpanel and drive a ground rod. Then somewhere in those years afterwards, they all changed to requiring 4 wires and a ground rod. So maybe what I was thinking of was separate buildings. Thanks

I believe it was the 2005 code.