16mm earth

[coltmanneil]

I have an earth wire on my system which might possibly need upgraded.
My main cable comes into the house then the earth wire is taken off a clamp off the armour on the cable.This then goes to an earth junction box obviously was put in by the electricity board many years ago.From this junction there is an earth cable goes onto the main incoming gas pipe,and another earth cable that goes to the main consumer box.
All the earth cables in my house were changed 7 years ago when i moved in from 6mm and i changed them to 10mm.
Can you tell if the earth that goes from the main incoming to the consumer box should be 16mm now under new regs.

Thanks all.

 

[davy_owen_88]

You have a TN-S earthing arrangement. The size of the main earthing conductor and equipotential bonding conductors (the cables to gas/water) are determined by the size of the phase conductor in the supply cable. Since you probably do not know what that is generally 10mm² is fine for MEB's and 16mm² for main earthing conductors.

These regulations are not retrospective, so you don't have to upgrade as soon as they change the regs.

 

[Qedelec]

My main cable comes into the house then the earth wire is taken off a clamp off the armour on the cable.

I hope this is sweated on, and not a clamp!

 

[Taylortwocities]

95% of the earthing conductors on TN-S round here are clamped, not sweated on.

TTC

 

[sparkyspike]

I hope this is sweated on, and not a clamp!

Why?

 

[Adam_151]

I hope this is sweated on, and not a clamp!

Why?

BS951 clamps are not designed for cable sheaths, however if it was installed by the DNO then either they may have satisfied themselves that the way they have used it is enough to meet their safety requirements dispite said use being outside of BS951, or it might be a different type of clamp designed for cables, or I suppose it might have been installed by a jointer who just doesn't care, or was installed years ago and the DNO don't approve...may be worth giving them a call and seeing if they want to remove it and sweat an earth on, if they are happy with it then as long as its not loose and you get a good Ze... afterall its their equipment and neither you nor BS7671 has much influence over it...

 

[coltmanneil]

It is clamped on ,and when i moved in 7-8 years ago the nice man from the electricity board came to inspect the meter and fuse etc.If it had to be sweated/soldered on surely he would have told us then.
My bathroom was part-p inspected 1 month ago and the lad told me to change the earth then ,unfortunately i cant remember which earth wire he told me to change.???
He was on about the main consumer unit,so could it be from main consumer unit to incoming earth wire.??


Thanks.

 

[Taylortwocities]

There's no such thing as a "Part P" inspection.
Part P is a section of Building Regulations.
Your electrician probably inspected to determine what if anything did not comply with the Electrical installation regs (BS7671).
If that is what was done you should be getting a detailed report (Periodic Inspection Report) that will tell you exactly what conductors are undersized.

TTC

 

[coltmanneil]

The electrician had to the testing on the bathroom as he had installed 3 x downlighters.The bathroom company would not let me do it as i was not a recogised electrician.He did Part P the installation and we got a certificate 3 weeks later.

I have done 16th many years ago ,but when the lads these days talk about the Part P ,i have to admit (being a electrician for 20years)i am a bit lost with this requirement.

The same lad who carried out the above was the one whom mentioned the 16mm earth.

 

[Chri5]

Are these clamps allowed / used by DNO's

 

[Spark123]

I hope not, those are for connecting to a gland such as a SWA gland instead of using a banjo aren't they??

 

[RF Lighting]

our DNO now uses sprung metal straps onto a braided cable insted of BS951 clamps