PME supplementary bonding conductor size

[tomek0410]

Hallo there,

I have a PME-fed installation. The neutral conductor is less than 35 mm so I have to use 10 mm for main equipotential bonding (that is water,gas).

1 What conductor size do I use for supplementary bonding (radiators, bathroom pipework)? Is it 6mm or 10mm?

2 Is it alright to connect backbox to socket with 2,5mm G&Y

Thanks

 

[ricicle]

1] 544.2 or 701.415.2 ?

 

[PrenticeBoyofDerry]

1) not less than 4mm
2) I would personally, use the same size or greater than the CPC of the circuit assosiated to the back box. But it is not a requirement to connect an earth to metal back boxes, providing one of the plate fixing lugs is fixed.

 

[JohnD]

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[tomek0410]

Thank you all for your responses,

1] 544.2 or 701.415.2 ?

So my understanding is that 544.2 applies also to PME conditons and the CSA of supplementary bonding conductor has to be 4mm with 2.5 T&E. Is that right?

 

[PrenticeBoyofDerry]

So if that was the case with respects to 544.2.
What if you had a shower circuit with 10.0mm line and 4.0mm cpc?
what difference would it make?

 

[tomek0410]

So if that was the case with respects to 544.2.
What if you had a shower circuit with 10.0mm line and 4.0mm cpc?
what difference would it make?

I think that would be correct because csa of cpc is equal to csa of bonding conductor. With 16mm live and 6mm cpc the csa of bonding conductor would have to be minimum of 6mm.

 

[ricicle]

]

So my understanding is that 544.2 applies also to PME conditons

Correct. It applies to all the common usage earthing systems.

the CSA of supplementary bonding conductor has to be 4mm with 2.5 T&E

If you mean a 4mm SBC is required with a circuit fed with 2.5mm² then yes if the SBC is unprotected (mechanically)