|
1 members (Scott35),
198
guests, and
10
robots. |
|
Key:
Admin,
Global Mod,
Mod
|
|
|
|
Joined: Jul 2004
Posts: 9,931 Likes: 34
Member
|
I guess it all comes down to how you read 110.3(B) and the label in the panel.
Greg Fretwell
|
|
|
|
|
Joined: May 2001
Posts: 378
Member
|
If it takes a little extra time to make the any installation better or safer why not?Inspection has never requested or ordered that i install a the jumper but it is logical code or not.The code is just the bare minimum required by law.Good call gfretwell.
|
|
|
|
|
Joined: May 2002
Posts: 110
Member
|
If you need more grounding terminals how about replacing the exsisting ground bar with a longer one that has more terminal screws?
Blessings.
Mark
|
|
|
|
|
Joined: Jan 2002
Posts: 1,457
Member
|
Use existing holes, drill and tap, whatever. No need for a jumper.
|
|
|
|
|
Joined: Apr 2005
Posts: 65
Member
|
Not long ago I had a similar problem with an old exterior main. Factory ground bar and no exra mounting screw holes( they didn't need them a few years ago). I choose the bonding jumper option ( solid #4). Since your not trying to bond the panel it doesn't matter about mounting hardware( can tap holes ). The rule on not using sheet metal screws is to keep people from using them to bond the panel, if they loosen, you would not have a good mechanical connection.I agree with gfretwell. I have seen loose ground bars in panels with factory screws.I think there should be a nice big factory welded lug there for bonding. I have this fear of grabing a live panel cover. allways touch with the back of my hand first.
|
|
|
|
|
Joined: Dec 2004
Posts: 209
Member
|
Seems to me that the machine thread screw is there to bond the panel enclosure. I don't think that screw would be rated to carry a fault from say a 50 amp range. Seems the screw would burn up if it were trying to carry that load to ground. I agree it should have a jumper wire from a lug on the original ground bar to a lug on the second ground bar.
|
|
|
|
|
Joined: Feb 2005
Posts: 693
Member
|
I noticed that the original poster never responded, but I took the question to mean that he's installing a grounding bar to separate the grounds and neutrals, as in a sub-panel.
If this is correct, then naturally, the jumper mentioned first by GF would be contra-indicated.
As an aside, in most cases, a 1/4x20 screw is used to bond a breaker cabinet, and would most certainly be capable of carrying a 50-amp fault current.
Larry Fine
Fine Electric Co.
fineelectricco.com
|
|
|
|
|
Joined: Feb 2002
Posts: 2,233
Member
|
Why not just bolt and nut an extra ground bar to the side of the panel. That would work just as well as the factory and don't forget to remove the paint for a good connection.
|
|
|
|
|
Joined: Jan 2005
Posts: 5,445 Likes: 3
Cat Servant Member
|
Harold, the reason I see this a a situation requiring a bonding jumper is that I don't see the steel case as mich of a cunductor at all. Why, even if the case were made of copper, how much of a cross section is there (think diameter of screw x thickness of case). What is that equal to? 10 gage wire? I see the screws bonding the case to the bar, and not the other way around. I'd bond the bars together with a piece of #8 wire. Just to be sure.
|
|
|
|
|
Joined: Jan 2002
Posts: 1,457
Member
|
For you guys that feel a bonding jumper is neccesary, why would not on manufacturer or the NEC require it? Because it is not needed.
|
|
|
|
Posts: 8,443
Joined: July 2002
|
|
|
|
