Panel bolted to building steel

[kbsparky]

I have a new installation where the main panel is bolted directly to the building steel.

Do I still need a copper jumper from the panel's grounding buss to a lug on the steel?

Why or why not?

 

[infinity]

Are you asking about a GEC to the steel?

 

[kbsparky]

Yes, if the panel enclosure is made of steel, and bolted directly to the building steel, is it still necessary to install a copper jumper wire? Why or why not?

 

[cadpoint]

You have to bond to larger structural framing, I'm thinking IE super structure not smaller component like framing of structure. Frankly I got stuck on the the thought of metal siding, BUT

Here's my example that it's on the web framing of a building, or even if its on a column exposed!

I'm still going to say that you need to bring a wire out for the major or minor framing, hopefully major framing and touch it independently of the panel.

Why, Cause it says to.

 

[Noseykat]

sorry to bother

sorry to bother

You have to bond to larger structural framing, I'm thinking IE super structure not smaller component like framing of structure. Frankly I got stuck on the the thought of metal siding, BUT

Here's my example that it's on the web framing of a building, or even if its on a column exposed!

I'm still going to say that you need to bring a wire out for the major or minor framing, hopefully major framing and touch it independently of the panel.

Why, Cause it says to.

how do i ask a question on this forum

 

[yankj]

Use GEC because the panel probably can not be secured well enough to carry the current that may be imposed. Just to be safe; a little wire and a lug; worth the investment.

 

[jumper]

Yes, if the panel enclosure is made of steel, and bolted directly to the building steel, is it still necessary to install a copper jumper wire? Why or why not?

Assuming the building steel is an electrode, I would say 250.24(A)(1) says you need a GEC to the steel. I do not think you can use the panel enclosure as part of your GEC.

(1) General. The grounding electrode conductor connection
shall be made at any accessible point from the load end
of the service drop or service lateral to and including the
terminal or bus to which the grounded service conductor is
connected at the service disconnecting means.

 

[earlejohnson]

how do i ask a question on this forum

You just did.

 

[Dennis Alwon]

250.102 says screws can be used as bonding jumpers but they shall be copper or other corrosive resistant material. Attachment would be based on 250.8 or 250.70 for GEC

 

[kbsparky]

Assuming the building steel is an electrode, I would say 250.24(A)(1) says you need a GEC to the steel. I do not think you can use the panel enclosure as part of your GEC.

(1) General. The grounding electrode conductor connection
shall be made at any accessible point from the load end
of the service drop or service lateral to and including the
terminal or bus to which the grounded service conductor is
connected at the service disconnecting means.

The problem here is this particular panel is not a "Service" per se, but a sub-panel fed from another building on the same premises. Therefore, there is no connection to the "grounded" conductor, but only the equipment bonding conductor (EGC?) should be connected to the steel.

So the EGC is connected to a grounding bar, bolted to the enclosure. The enclosure is bolted to the building steel. Seems kind of silly to install a jumper wire out the back of the panel onto a lug on the steel, doesn't it?

 

[Dennis Alwon]

The problem here is this particular panel is not a "Service" per se, but a sub-panel fed from another building on the same premises. Therefore, there is no connection to the "grounded" conductor, but only the equipment bonding conductor (EGC?) should be connected to the steel.

So the EGC is connected to a grounding bar, bolted to the enclosure. The enclosure is bolted to the building steel. Seems kind of silly to install a jumper wire out the back of the panel onto a lug on the steel, doesn't it?

Well is the steel an grounding electrode??? If not then I think the screw is enough. If it isn't a ge then you need to drive some rods anyway.