Is this considered a Sub-Panel or Not?

[roger]

Re: Is this considered a Sub-Panel or Not?

Gerorge, you are thinking within the confines of your book, my points are only for exercise in the reason, think of a buss duct with a main at one end and a section with breakers at the other end 100' away.

Does that answer your Waaaa?

BTW, are you sure there are two GEC's?

Neils read 250.142

Roger

[ April 27, 2005, 08:08 AM: Message edited by: roger ]

 

[George Stolz]

Re: Is this considered a Sub-Panel or Not?

Roegerer,
Ever watch Jon Stewart? I must give credit for the "Waaaa?".

I know, there's not two GEC's, but it's easier to say that than get even more technical. I've been chastised and straightened out by Bob, and still can't remember the other one's a hooting conductor or something.

ATROEMI, what is a buss duct? Build-your-own-100'-panel-looking-thing?

[ April 27, 2005, 08:12 AM: Message edited by: georgestolz ]

 

[George Stolz]

Re: Is this considered a Sub-Panel or Not?

I think it's pretty funny nobody seems to care about the DIY factor in this. :roll:

 

[iwire]

Re: Is this considered a Sub-Panel or Not?

Originally posted by georgestolz:
I've been chastised and straightened out by Bob,

Only to help you.

 

[roger]

Re: Is this considered a Sub-Panel or Not?

Geoergerer,

ATROEMI, what is a buss duct? Build-your-own-100'-panel-looking-thing?

buss ducts (Buss ways) are factory assemblies see 368

Roger

 

[iwire]

Re: Is this considered a Sub-Panel or Not?

Originally posted by georgestolz:
what is a buss duct?

A grounded metal enclosure containing factory-mounted, bare or insulated conductors, which are usually copper or aluminum bars, rods, or tubes.

A typical use of this I work with would vertical risers in multi story buildings.

Run a 1000 to 4000 amp bus duct from the service gear in the basement vertically through the electric rooms on each floor.

On the bus duct are spots where you literally "plug-in" a breaker or fused disconnect to tap power to feed that electric room.

In one electric room you may see multiple taps of the bus duct in sizes from 100 - 800 amps.

In some building the bus duct will rise all the way to the mechanical room on the top floor and feed a motor control center.

 

[kevinware]

Re: Is this considered a Sub-Panel or Not?

Ok everyone being an apprentice I really like to read the discussions between members that have more experience than myself I really learn a lot, I want to thank everyone for that, But I keep hitting a wall on this one. I am seeing the 200 amp service entering the outside enclosure and landing the phase conductors on the 200 amp breaker. Here comes the fog, does the incoming grounded conductor(white) land on the grounded bus and then bonded to the equipment grounding bus via the main bonding jumper for the outside panel only??? I appoligize for all the school terms but that is the only way I can see it in my head right now.
Thanks again,
Kevin

 

[infinity]

Re: Is this considered a Sub-Panel or Not?

Kevin,

In answer to your question, yes.

[ April 27, 2005, 11:58 AM: Message edited by: infinity ]

 

[jii]

Re: Is this considered a Sub-Panel or Not?

I appoligize for all the school terms but that is the only way I can see it in my head right now.

I don't know about every on else, but I love the school terms. It takes most of the confusion out of electrical conversations,Keep it up.

 

[physis]

Re: Is this considered a Sub-Panel or Not?

So Roger, you're saying that because both panels are the same piece of service equipment, you can mount a neutral terminal block to the enclosure of the inside panel and allow the connecting conduit or nipple to carry neutral current?

 

[roger]

Re: Is this considered a Sub-Panel or Not?

Sam, the neutral conductor (neutral buss extension ) would carry the neutral current, although there would be some paralleling current division. Would this be any different than the buss duct scenario? As Pierre questioned before, (in another thread) is there a limitation to the length of a piece of service equipment?

Kevin, I'm glad you are aware that these conversations are not in line with the NEC.

Roger

[ April 27, 2005, 12:59 PM: Message edited by: roger ]

 

[physis]

Re: Is this considered a Sub-Panel or Not?

Well tell me how you're going to handle the grounding and neutral terminal blocks mechanically. I keep thinking code violations.

 

[thinfool]

Re: Is this considered a Sub-Panel or Not?

the one place you can ground the neutral is at the service disconnect. nowhere else.
take a separate ground into the load center and install a ground bar for your circuit grounds.

Will it matter a lot? No. But we are talking about the code.

 

[roger]

Re: Is this considered a Sub-Panel or Not?

Sam,

Well tell me how you're going to handle the grounding and neutral terminal blocks mechanically.

regardless of how many, they would be one and the same.

Roger

 

[physis]

Re: Is this considered a Sub-Panel or Not?

Haa, so you admit it then.

Edit: You'll be using conduits as grounded conductors.

[ April 27, 2005, 01:40 PM: Message edited by: physis ]

 

[roger]

Re: Is this considered a Sub-Panel or Not?

Admit what? It's as I have been saying, there would be no separate grounding and grounded terminal bars, they would be common i.e. no separation.

Roger

 

[milwaukeesteve]

Re: Is this considered a Sub-Panel or Not?

Thinfool,
Be careful of your terminology. What you are saying is correct, but we would be Bonding our Grounded and our Grounding conductors together at the main panel.

Try not to say grounding our neutral, because we are not grounding anything. Both of those conductors are already connected to ground through different paths and directions. We are Bonding both of those together at the main panel.

 

[physis]

Re: Is this considered a Sub-Panel or Not?

Your proposed installation is in violation 250.6.

 

[roger]

Re: Is this considered a Sub-Panel or Not?

Why would a minute current be objectionable?

Roger

 

[milwaukeesteve]

Re: Is this considered a Sub-Panel or Not?

I think Kevin had a right to be confused earlier. If we have a main outside, we can not feed a main inside. But from Neils original post, I couldn't tell what he was describing.
Now Roger and Sam are arguing about Buss Extensions. If that Main is outside, the Bonding of your grounded and grounding (neutral and EGC) is outside. If the Main is inside, then it is all inside. To do both would result in parallel paths and possibly the raceway (if metal) becoming a current carrying conductor.
In regards to Buss Duct, at the other end of that duct, the grounded conductor is not bonded.
Kevin was correct in his assesment of the situatuion, and correct for using 'school' terms. Most of those terms are the correct terms. We probably could avoid some confusion if we all used the same terms.