Am I doing this right?

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zappy

Senior Member
Location
CA.
Customer house was built in the 50's. Old sub-panel has a feeder cable that doesn't have a neutral. Just 2 hots and a bare ground wire. All the neutrals and EGC's land on the same bar. I want to separate the EGC's from the neutrals. So I was going to pull a EGC from the main panel to the sub-panel. Add a ground bar to the enclosure, land the EGC from the main I pulled in. Then land all the EGC's in the sub-panel to it. And use the bare feeder cable ground as a neutral. Is this OK? Thank you for your help.
 

Dennis Alwon

Moderator
Staff member
Location
Chapel Hill, NC
Occupation
Retired Electrical Contractor
Zappy- look at 300.3(B)-- B(2) allows grounding and bonding outside the raceway but not grounded conductors.

300.3(B) Conductors of the Same Circuit. All conductors of the same circuit and, where used, the grounded conductor and all equipment grounding conductors and bonding conductors shall be contained within the same raceway, auxiliary gutter, cable tray, cablebus assembly, trench, cable, or cord, unless otherwise permitted in accordance with 300.3(B)(1) through (B)(4).
 

charlie b

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Location
Lockport, IL
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Retired Electrical Engineer
So I was going to pull a EGC from the main panel to the sub-panel.
If you are thinking about doing that, can't you instead pull a neutral (i.e., an insulated instead of bare wire)? Worst come to worst, I would try pulling the entire feeder back to the main panel, and replace it with a proper (3W + G) feeder.

 

Dennis Alwon

Moderator
Staff member
Location
Chapel Hill, NC
Occupation
Retired Electrical Contractor
If you are thinking about doing that, can't you instead pull a neutral (i.e., an insulated instead of bare wire)? Worst come to worst, I would try pulling the entire feeder back to the main panel, and replace it with a proper (3W + G) feeder.

Is that legal Charlie-- running a neutral outside the cable.
 

Dennis Alwon

Moderator
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Location
Chapel Hill, NC
Occupation
Retired Electrical Contractor
Zappy- how would you keep the bare wire in the cale from touching the cabinet. As Charlie says run a new cable and do it right.
 

zappy

Senior Member
Location
CA.
Well cost is always a factor, but of course I want to do it right too. So Charlie mentioned pulling a single insulated white conductor (neutral), from the main to the sub-panel. Will that be OK?
 

jwjrw

Senior Member
Well cost is always a factor, but of course I want to do it right too. So Charlie mentioned pulling a single insulated white conductor (neutral), from the main to the sub-panel. Will that be OK?

Dont think so because of what Dennis said.
 

Sierrasparky

Senior Member
Location
USA
Occupation
Electrician ,contractor
I think you should pull a new feeder. It does not sound like the existing feeder was code even at the time. I've seen a 3 wire feeder but no ground but never seen a unisulated neutral in a 120/240v feeder. I bet they only had 120v service and Illegaly converted it.

So Pull a new feeder and be done with it. Even a SER AL feeder is better than what you got !
 

LarryFine

Master Electrician Electric Contractor Richmond VA
Location
Henrico County, VA
Occupation
Electrical Contractor
Old sub-panel has a feeder cable that doesn't have a neutral. Just 2 hots and a bare ground wire.
Technically, it's a neutral; you don't have a separate EGC. Not legal in the same building.

The minimalist solution would be your new-EGC idea, plus removing any bonding jumper.

But, the bare neutral still isn't compliant, unless you white-tape it if it's bigger than #6.

But, all feeder conductors are supposed to be within in the same cable and/or raceway.

The only correct solution is to run a new 4-wire feeder, separating EGC's and neutrals.
 

George Stolz

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Location
Windsor, CO NEC: 2017
Occupation
Service Manager
Well cost is always a factor, but of course I want to do it right too.
Customers tend to beat us down to the point where we spend an inordinate amount of time considering doing something sketchy, that we would not be proud of later, and would feel guilty charging for as well. The price for doing it right would be even, if you take the time for designing it sketchy into consideration.

Establish what needs to be done: Install a new feeder. Establish the price. Everybody sleeps at night.
 

Dennis Alwon

Moderator
Staff member
Location
Chapel Hill, NC
Occupation
Retired Electrical Contractor
Customers tend to beat us down to the point where we spend an inordinate amount of time considering doing something sketchy, that we would not be proud of later, and would feel guilty charging for as well. The price for doing it right would be even, if you take the time for designing it sketchy into consideration.

Establish what needs to be done: Install a new feeder. Establish the price. Everybody sleeps at night.

Very well stated. I would like to add that I will sometimes, if necessary, charge the cost of the wire with no markup to alleviate the pain to the owner.

I hate being the bad guy so this makes me sleep better also. :)
 

Sierrasparky

Senior Member
Location
USA
Occupation
Electrician ,contractor
Was it ever legal for a Nuetral of a feeder for a sub to be uninsulated and not have a ground wire?
 

growler

Senior Member
Location
Atlanta,GA
Customer house was built in the 50's. Old sub-panel has a feeder cable that doesn't have a neutral. Just 2 hots and a bare ground wire. All the neutrals and EGC's land on the same bar. I want to separate the EGC's from the neutrals. So I was going to pull a EGC from the main panel to the sub-panel. Add a ground bar to the enclosure, land the EGC from the main I pulled in. Then land all the EGC's in the sub-panel to it. And use the bare feeder cable ground as a neutral. Is this OK? Thank you for your help.

Are you sure this bare ground wire is not the original neutral? In the 50s a ground wouldn't have been required. This sounds like old SE cable to me with 2 hots and an uninsulated neutral conductor.

If you want to bring it up to code that's great but if this is an original install there may not be a requirement to change it.

If you do the job it will need to be permited and inspected so call the local inspector and see if they would require this to be changed.
 

wwhitney

Senior Member
Location
Berkeley, CA
Occupation
Retired
Is that legal Charlie-- running a neutral outside the cable.
If this is non-metallic cable, wouldn't 300.3(B)(3) allow running a second non-metallic cable for the feeder neutral? Obviously you could not use THHN wire, but perhaps there is an economical single conductor cable that could be used. If the second cable is routed alongside the first one, the magnetic fields induced would be minimized. I'm not suggesting this is the best practice, just that it appears to be allowable.

Cheers, Wayne
 
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