TNCS SYSTEM

[markymark2406]

In my property i have a TNCS earthing, i need to bond my main gas pipe and main water pipe back to my dis board what size earthing do i need to use 10mm??? and can i earth through without cutting the wire e.g from my gas through the earthing strap of the water back to the dis board?

 

[Taylortwocities]

Yes 10mm bonding conductor.

Yes connect end at gas, loop conductor WITHOUT CUTTING IT through the earth strap on water pipe to your main earth terminal.

Main earth conductor from incomer to MET should be 16mm to comply with regs. Assuming your meter tails are 25mm.

 

[sealeon]

You can use a single earth so long as there is no breaks in the cable I believe and 10mm is fine if your supply neutral is less than thirty five mm

 

[Spark123]

10mm is probably the right size but you should check with your distribution network operator as they can over rule this.
There is nothing stopping you using the same conductor for both as long as the conductor remains unbroken thoughout its length.
How long is the cable going to be? The resistance of the main protective bonding should not exceed 0.05ohms to from its remote point to the MET.

 

[sealeon]

Main earth conductor from incomer to MET should be 16mm to comply with regs. Assuming your meter tails are 25mm.

I thought it was 10mm if the incoming neutral was less than 35mm and 16 was for over 35 and less than 50

 

[Spark123]

The Earthing Conductor is the one connecting your MET to the source of earthing, in TNCS the DNO's terminal.
Main protective bonding conductors connect extraneous conductive parts such as metallic water and gas services to the MET.