Candidate for the most pointless earthing ?

Joined
4 Nov 2010
Messages
6,046
Reaction score
620
Location
Cumbria
Country
United Kingdom
Where I work has recently put up a multi storey car park, and while walking past the other day I noticed that every 3-4 posts along the side I can see from the road there is a strap bolted to the post and going to an earth rod box.
It's a steel frame, all bolted together, with something getting on for 150 posts - each of which is fixed to 4 bolts set in a block of concrete. OK, so the bolts won't be set all that deep, but with an array of them covering the whole area of the car park I suspect just the fixing bolts make a formidable earth grid. There's no EV chargers installed before anyone asks.
And it's not like there's a lot of electrical equipment in/on it - just the access controls & barriers, and the usual lights.

So I do find myself wondering what the thought process was in the mind of the person who decided the extra earth rods were needed.
 
Sponsored Links
Joined
4 Nov 2010
Messages
6,046
Reaction score
620
Location
Cumbria
Country
United Kingdom
I assume that's a typo for lightning ?
Even so, there's already in excess of 600 small electrodes distributed over an area large enough for about 400 cars. Seems pretty pointless to me.
 
Joined
3 Nov 2006
Messages
27,287
Reaction score
3,006
Location
Bedfordshire
Country
United Kingdom
To me a strap suggest it is lightning protection rather than earthing and/or bonding.

Lightning protection requires the ability to carry current that are several thousands of Amps to ground for the duration of the strike.

Bonding cables would likely melt before the strike ended.
 
Sponsored Links
Joined
30 Jun 2008
Messages
15,529
Reaction score
1,811
Location
Suffolk
Country
United Kingdom
They are lightening straps and you may find on closer inspection they run up inside the steel framework.
The college I work at has a cross grid of thick copper strips across the roof, all securely held down with clamps every few feet, and this grid work is connected to 28 strips running down the side of the building at various points to individual earth rods in the ground terminating in pots and covered with a screw down lid. A contractor was in during half term checking every connection and clamp fitting. Took him 2 days.
 

DIYnot Local

Staff member

If you need to find a tradesperson to get your job done, please try our local search below, or if you are doing it yourself you can find suppliers local to you.

Select the supplier or trade you require, enter your location to begin your search.


Are you a trade or supplier? You can create your listing free at DIYnot Local

 
Top