Bonding balconies

[SLIPSHOD & SLAPDASH]

I have had a very busy day &  somethings bugging me if my thoughts are correct, so after a  few drinks tonight  i thought i would ask you lot.

Firstly, can you be sure what  this supply is , the earth connection is internally connected to N  . What bugs me is the additional earth brought in with the supply (its 50mm) I know it was common for the supplier to bring an extra earth in  when multiple meters are to be fitted but they were always black and i never saw bigger than 16mm ?





PS First to spot a few serious faults in this pic wins nothing  ( well the whole building is wrong all wrong, but i am compiling up a set of pics before i post them)

Back to the point of this post, This is a new steel framed block of 9 flats. The building is in the process of having 3 sets of steel balconies fitted that are welded to the original steel framework of the structure and also each have steel legs going into the ground. Each set of balconies covers ground to 3rd floor & each flat ( 3 on each balcony structure )has a light wired to its own supply on the new balconies.  I was thinking each set of balconies will need bonding back to the MET, but now i am thinking as they are welded to the structure is this needed ?

The tails are 95mm  now with a 50mm main earth. Each flat has a 25mm main earth from its consumer unit to the metering point. Is the steel structure bonded-i doubt it.

 

[Andy™]

if each property is its own installation, then the balcony being welded to the steel frame may be extraneous and need bonded

 

[ruston]

I hope the welders are better than the 'electricians.'

 

[SLIPSHOD & SLAPDASH]

I was thinking it did not need bonding as its now part of the steel structure with multiple points in the ground. I doubt  any of the structure has been bonded ( which now makes me think it should be bonded)

 

[Rob_the_rich]

I think you are over thinking whether it is extraneous or not. Test in the morning.

Surely the structural steel needs bonding at the supply room MET irrespective of whether each flat might be found to need their own bonding.

Where is the installation's earthing conductor connected to the neutral (PEN) tail?

Edit; are you sure it is the DNO's additional earth and not the bonding to the steelwork? Or perhaps it is both?

 

[Tony S]

There’s a N→E link in that make of service head, the type of supply dictates if the link is fitted or not. Personally I’d bond to the structure and forget the balconies.

As for the rest (I’ve enlarged the photographs) I wish you luck.

 

[ruston]

Me too.

 

[Tony S]

I hope the welders are better than the 'electricians.'

Come and look at the viewwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwww SPLAT!

 

[ruston]

I do not know if I would trust them with nuts and bolts lol.

 

[apprentice87]

I dunno... PME and the armour in the service cable not large enough to serve as earth/bonding conductor?? [which is why they have an additional one]

Tails not secured?

Tails all pass through different holes?

No labelling??

But best of all... Why does the bonding of the building not appear to be connected to the MET??? and why does there not appear to be an earthing conductor connected to the MET either???

[If it was intended to be TT there would have to be a rather large RCCB at the origin]

Nothing wrong with using the structure of a steel building as a means of bonding though..

john..

 

[Sidewinder]

Forget bonding the balconies they are part of the structural steel work if welded to it internal or external.

Make sure the steel work is bonded correctly and sorted.

 

[Tony S]

Have a look through this LV supplies above 100A it should explain the cable size and type. My monies on 95mm² wavecon.