Corner grounded delta

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JohnJ0906

JohnJ0906

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Baltimore, MD
A freind of mine was looking at a job, for an estimate to redo an existing service. (Old church) He was wondering if this instal was legal, and asked me.
Since I am not sure, I am asking you... ;)

In addition to a 120/240v 1 ph service, there is an additional 240v, 3 ph, 3w service. (corner grounded delta) The original installers used SE cable, 2 insulated, and the bare for the corner grounded leg. Is it legal to use an uninsulated conductor for this?
 
JohnJ0906 said:
In addition to a 120/240v 1 ph service, there is an additional 240v, 3 ph, 3w service. (corner grounded delta) The original installers used SE cable, 2 insulated, and the bare for the corner grounded leg. Is it legal to use an uninsulated conductor for this?
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Not past the service disconnect.

Just as with any other grounded circuit conductor, beyond the bonding point it is to be insulated or marked white, isolated from ground, and never broken unless simultaneously with the ungrounded lines.

It is a circuit conductor, and carries full current.
 
LarryFine said:
Not past the service disconnect. Just as with any other grounded circuit conductor, beyond the bonding point, it is to be insulated or marked white, isolated from ground, and never broken unless simultaneously with the ungrounded lines. It is a circuit conductor, and carries full current.
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OK, but it is ok on the line side of the main service disconnect? (That is where it is)
 
JohnJ0906 said:
OK, but it is ok on the line side of the main service disconnect? (That is where it is)
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Yes. It's really no different than the bare neutral conductor in your service triplex or cable, except for no sizing reductions.
 
LarryFine said:
Yes. It's really no different than the bare neutral conductor in your service triplex or cable, except for no sizing reductions.
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Thats kind of what I thought, but seeing a bare for a phase conductor seems a little wierd.
 
In my area SE comes with a reduced size bare conductor, it might be worth checking the size of the bare and make sure it is large enough for the OCP.



BTW .... I am really PWI so check my facts.:D
 
iwire said:
In my area SE comes with a reduced size bare conductor, it might be worth checking the size of the bare and make sure it is large enough for the OCP.
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Usually, we see same size SEU - bare same as insulated. SER has a reduced bare.



BTW .... I am really PWI so check my facts.:D
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Say it ain't so Bob! :D
 
JohnJ0906 said:
Usually, we see same size SEU - bare same as insulated. SER has a reduced bare.
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Are you sure? It's hard to tell cause ya got twist it yourself.

Here the bare is often one or two sizes under the two insulated





Say it ain't so Bob! :D
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Just back from BBQ, Tequila, beer and food, it's a great country. :cool:
 
iwire said:
Are you sure? It's hard to tell cause ya got twist it yourself.
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I'm positive.

OK, can I get a NEC article permits this? 310.2(A) requires conductors to be insulated, unless permitted elsewhere. I know it is in here somewhere, but can't seem to locate it.
 
iwire said:
BTW .... I am really PWI so check my facts.:D
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I don't know....you must not be too "I" if you can still put together a coherent sentence on a computer. ;)

As for the SEU cable, I have installed both varieties - full size bare and reduced. IIRC, the reduced size "ground" in the 2/3 SER was a #4.
 
peter d said:
I don't know....you must not be too "I" if you can still put together a coherent sentence on a computer. ;)

As for the SEU cable, I have installed both varieties - full size bare and reduced. IIRC, the reduced size "ground" in the 2/3 SER was a #4.
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SEU or SER?

I always see SER with a reduced bare, but not SEU.
 
JohnJ0906 said:
Usually, we see same size SEU - bare same as insulated.
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I get it both ways, but not on purpose. I just order it by "200 amp SE cable", and get it most of the time with a reduced bare. From time to time, it will come through with a full sized bare. I'm paying the same for either, near as I can tell. I use my cordless drill to wind it up, so I can always tell right away when I go to twist it up. A bundle of 3/0 strands fits in the drill chuck more easily than a bundle of 4/0 strands. Otherwise, I'd probably never realize.
 
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