main bonding to structural steel

[bredon86]

what size is acceptably?
how to terminate bonding to steel (clamp or)

cheers

 

[Deleted member 9648]

Bonding conductor sized the same as any other bonding conductor......

 

[D Skelton]

Personally I'd drill a small hole and use an eyelet crimp with a roofing nut and bolt. I'm ready for others to object to this method however

 

[Deleted member 26818]

You can get clamps for this, similar (but much larger) to the ones used sometimes to bond radiators.

 

[Knobhead]

You don’t drill structural steel work with out the say so (in writing) of a structural engineer. Save yourself a lot of earache and use clamps.

 

[Guest123]

what size is acceptably?

Regulation group 544.

 

[ezzzekiel]

You don’t drill structural steel work with out the say so (in writing) of a structural engineer. Save yourself a lot of earache and use clamps.

allow i see your point i cant see something the size of a bolt causing much damage to structual steel but if it could it would be pretty good to watch

 

[telectrix]

i've drilled 20mm holes in structural steel and bushed 'em for cable runs. only same as drilling a joist. if a girder can't hold up what it's supposed to hold up with a good safety margin, then it's been designed wrong.

 

[Knobhead]

OK you drill your 6mm hole, along comes the next guy and starts drilling 20mm holes. The simple rule is structural steel no holes.

 

[benji]

very iffy drilling structural steelwork without consent ,look at furse catalogue for bonding clamps

 

[Engineer54]

Depends what your drilling the structural steel for, ....If your drilling and tapping for a bolted connection, there shouldn't be any problem, or a suitably sized nut and bolt come to that!!! It's a bit different drilling a 20mm hole for a cable to pass through. But then again i've heard so many different views from Structural Engineers, that basically applying the commonsense attitude, you'll rarely if ever cause any detrimental affects to building structural steelwork....

On most of the projects i've been involved on over the last 15 years or so, actual connections to structural steelwork for say earthing or grounding connections, have mainly been via ''cad-welding (exothermic welding). There are molds available for just about any circumstance you may need....

 

[04gallsopp]

I read that the bonding conductors must be no less than half of the main incoming to the building . So if its 16mm tails the minimum bond must be 8mm.

 

[04gallsopp]

and you get large versions of the rad clamps

 

[Engineer54]

I read that the bonding conductors must be no less than half of the main incoming to the building . So if its 16mm tails the minimum bond must be 8mm.

Ah, ....Now you are talking here basically domestic!!! Most Steel framed, or buildings where there is going to be Structural Steelwork is going to be in the Commercial/Industrial sectors. And there main incoming supplies and be significantly bigger than 16mm tails.
You could well be dealing with 185mm/240mm or larger bonding conductors...

 

[04gallsopp]

Ah, ....Now you are talking here basically domestic!!! Most Steel framed, or buildings where there is going to be Structural Steelwork is going to be in the Commercial/Industrial sectors. And there main incoming supplies and be significantly bigger than 16mm tails.
You could well be dealing with 185mm/240mm or larger bonding conductors...

i know im talking domestic but surly no matter how big the tales the same rule applys

 

[Deleted member 26818]

More or less, I believe with TN-S the maximum required is 25mm², and with TN-C-S 50mm².