earthing not to 7671

[tincatinca]

have just had a look at my earthing,the main earthing conductor to my c/u is no more than 4mm.can i get the supply company to bring this up to date,also will i have to pay for it.second question is, the gas company re-routed my gas supply .it now comes in by the garage door to the meter, it then goes across the roof down the wall into the cupboard where the electric comes in .can i bond the gas pipe in the cupboard or do i have to take the wire across the garage to the gas meter. thanks in anticipation

 

[Lectrician]

You should bond with in 600mm of the gas meter, before any tees, OR where the pipe enters the building if the meter/pipework is external.

This also applies to the mains cold water supply coming in.

Use 10mm for this 'main equipotential bonding', and use 16mm to the elec board.

The main earth to the elec board is your cable. You could replace it with a new one, temporarily joined to the old 4mm, then ask the elec board to conect the final end up (while you are at that, you should also install 25mm mains tails, as i would think yours are still 16mm). The elec boards sometimes charge a fee for the conection, they WONT replace the cables for you.

 

[dingbat]

It's worth noting that BS951 earth clamps are designed to fit to rigid pipes and NOT to the sheathing on TN-S systems. The REC should fit you a proper braided strap to make the connection to their earth conductor. As Lectrician says, connect your new cable to the existing one and leave the final connection to the rec.

 

[tincatinca]

thanks for that info.i do not see the point of running a10mm cable about 6metres alongside the copper gas pipe to connect to the earth bar when that same pipe runs past the same earth bar 300mm from it.

 

[securespark]

You should bond with in 600mm of the gas meter, before any tees, OR where the pipe enters the building if the meter/pipework is external.

This also applies to the mains cold water supply coming in.

Can I just clarify? Lectrician is perfectly correct to say the above. If you don't have an external water meter:

You need to bond the mains water on the "house" side of the stopcock near to the cock, not on the "street" side, assuming it is metallic. If it is plastic, then you'll have to bond where it changes to copper. If you have an internal meter, it is best "bridged" with a bonding conductor of 10mm2 and two earth clamps.

 

[dingbat]

A further comment: The pipework up to the meter is classed a service pipe. The pipework after the meter is known as the installation pipe. While reg 413-02-02 may require bonding to any exposed service pipe inside a consumer's premises as well as the installation pipe, the connection should not be made to the service pipe without the express consent of the owner of that pipe.

 

[Lectrician]

Securespark is 100% correct. I generalised a little with the water.