Structual steel/ lighitning protection bond

[Strickers]

Could anyone clear this up for me. If you have lightining protection on a steel framed building is it still necessary to bond the structual steel work as the lighting protection is bonded all around the building. Or is the lighting protection classed as supplementary bonding and you should still bond structual steel. Seems a bit of a grey area and i've been told differently from different people.

 

[Sparky_Ben]

I was under the impression that the lightning protection had a connection back to the main earth terminal to give the same potential. But i would say that as it is a seperate part of the installation maybe done by a specialist contractor that it should be bonded directly from the MET.

 

[Deleted member 9648]

The structural steel must be main bonded back to the MET
Lightning protection should also be main bonded back to the MET...(I've never been able to understand the reason for this given that it never enters the equipotential zone)....BUT,main bonding of the lightning protection should only be undertaken after consulting a lightning protection specialist.

 

[Sparky_Ben]

im glad someone agreed with my post seems my theory work at colege is sinking in

 

[Sintra]

Lightning protection is not connected to the MET but to the natural earth.

Bonding for structural steelwork should be installed as normal.

In Cuba we were working in a large metal sided building and on our spec it stated that lightning protection system had to be insulated from building metalwork with insulated clamps.

 

[Sparky_Ben]

I was under the impression that it was connection from the test point back to the MET?

 

[davelerave]

Lightning protection is not connected to the MET but to the natural earth.

Bonding for structural steelwork should be installed as normal.

In Cuba we were working in a large metal sided building and on our spec it stated that lightning protection system had to be insulated from building metalwork with insulated clamps.

don't know much
but i though structural steel and lightning rods were connected to prevent flashover/fire

 

[Sintra]

Ok some of the info i have given in this thread appears to be incorrect.

I found some more info on lightning protection and see that you should bond to MET unless the design of the lightning protection system does not require it.

In my experiences of lightning protection mainly in South America it was on spec not to bond back do MET.

Found this Lightning protection systems - The common snag and its solution from the NICEIC - Edmundson Electrical

 

[Strickers]

Thanks for all your replies, i've spoken to our consultant and he's said that main structual steel bond back to MET and bond lighting protection to building and through earth spike at the end of each tape. Thanks again Paul