main bonding jumper

[buck33k]

A service panel (not a sub panel) has the grounded conductors bonded to the can by the green screw provided for this purpose.
A separate additional grounding bar is bolted in the enclosure for branch circuit equiptment grounding conductors.
Does the grounding bar require additional bonding to the neutral sized per 250.66?
Buck

 

[dillon3c]

Re: main bonding jumper

Buck,
No,you are not in the requirement of having to do both.You can do, either one of the two.
see 250.24(4) and 250.28(b)

You may install green Main bonding jumper screw in (grounded) conductor terminal bar to enclosure.-or-

250.24 or install main bonding jumper as wire or bus from the (grounded) terminal bar,to the (grounding) terminal bar attached to enclosure..

[ June 16, 2005, 11:21 PM: Message edited by: dillon3c ]

 

[buck33k]

Re: main bonding jumper

Thanks Dillon. So, it seems that if you wanted to land the grounding electrode conductor on the separate equipment grounding terminal bar, you would need the wire bonding jumper, otherwise not.
In the event the GEC were connected to the separate grounding terminal bar, and bonding was with a wire bonding jumper, would it be prohibited to also use the green bonding screw, although unnecessary? Sorry to complicate things.

 

[dillon3c]

Re: main bonding jumper

Originally posted by buck33k:
[QB] would it be prohibited to also use the green bonding screw, although unnecessary?

You are only in requirement to bond the (grounded) service entrance conductor with main bonding jumper,-once - at the point of Main Service Disconnecting Means, of the separately derived system.

[ June 17, 2005, 07:13 AM: Message edited by: dillon3c ]

 

[George Stolz]

Re: main bonding jumper

Originally posted by buck33k:
In the event the GEC were connected to the separate grounding terminal bar, and bonding was with a wire bonding jumper, would it be prohibited to also use the green bonding screw, although unnecessary?

If the panel comes with a "wire" bonding jumper between neutral and grounding bars, then it seems odd they'd also provide a bonding screw.

By "once", I believe Dillon is referring to the fact that the bonding screw does the job. This is once. If you choose to augment that bonding with a chunk of #6, feel free, it's extra.

So, it seems that if you wanted to land the grounding electrode conductor on the separate equipment grounding terminal bar, you would need the wire bonding jumper, otherwise not.

250.28(A) Material. Main bonding jumpers shall be of copper or other corrosion-resistant material. A bonding jumper shall be a wire, bus, screw, or similar suitable conductor.

The screw is a suitable Main Bonding Jumper. NEC says so, and it's listed that way. If the Main Disconnect Panel comes with a screw, use it and you're done.

[ June 17, 2005, 07:58 AM: Message edited by: georgestolz ]

 

[buck33k]

Re: main bonding jumper

If the panel comes with a "wire" bonding jumper between neutral and grounding bars, then it seems odd they'd also provide a bonding screw

My question was referencing the addition of a grounding terminal bar supplied as a kit, and connecting the GEC to it. The panel is not supplied with two methods for bonding.

 

[dillon3c]

Re: main bonding jumper

Morning Buck,
Question: And I got to ask.. Have you already installed the GEC to the equipment grounding terminal bar?

Just wondering in your reasoning for, in might be exploring the options?

 

[buck33k]

Re: main bonding jumper

Dillon
Yes, the GEC is installed in the added terminal bar. This is an unusual situation in that the service panel may not always remain the service disconnect, and so the separation of the equipment grounding conductors and neutrals now. Otherwise I would'nt have added the grounding bar. Your reference to 250.24(A)(4) really helped.

edited to add, Better head to work, be back tonite and thanks for the responces so far.

[ June 17, 2005, 09:59 AM: Message edited by: buck33k ]

 

[dillon3c]

Re: main bonding jumper

Buck...

You have a good morning sir..

 

[don_resqcapt19]

Re: main bonding jumper

If the main bonding jumper is not a wire or a busbar, then the GEC must be connected to the grounded conductor busbar. 250.24(A)(4).