Earth bonding to incoming gas supply.

[Spark123]

A TN-S system with 25mm² requires a main earthing conductor of 16mm² (table 54G) therefore the main equipotential bonding conductors need to be a minimum of 8mm², the next size up being 10mm².

does it have to be 25mm?

Depends on the size of the supply.
If you work it out for 16mm² you will still end up with 10mm² MEBs.

 

[ELZ4742]

but that was my point to secureblokey, its not, NTCS...
if you have 16mm tails a 16mm main earth isnt required is it? 10mm is fine. there for 1/2 x section = 5mm

 

[Spark123]

What does table 54G say?

 

[ELZ4742]

its cross sectional of the phase conductor right? so 16 with 16, ok my mistake. although technically im not wrong

 

[Spark123]

What do you mean by technically? If MEBs are not up to size then it is as Securespark says, NTCS.

 

[ELZ4742]

if it were a 10mm supply?

 

[Lectrician]

Get over it. We know it's in relation to the neutral conductor - there is a chart in the regs for all to see.

So what is the maximum you have to go for TN-S and TN-C-S?




Oh - and when someone commented earlier "should be calced" or similar, I assume they where refering to making sure the MEBs resistance was below that required when testing........which is?

 

[blondini]

Wow! Two pages... and a slap from a Mod

Thanks Guys. Pretty much as I thought, just needed some reassurance. There's no bonding directly to the incoming water either so there's another cable to run. I have another question but I'll post that seperately. The more I look, the more I find.

 

[luminaire]

Just bond it in 10mm, 600mm on the incoming side and have done.

 

[securespark]

 

[ELZ4742]

Get over it. We know it's in relation to the neutral conductor - there is a chart in the regs for all to see.

So what is the maximum you have to go for TN-S and TN-C-S?




Oh - and when someone commented earlier "should be calced" or similar, I assume they where refering to making sure the MEBs resistance was below that required when testing........which is?

a bit harsh, just a f****n mate
this is a forum for questions and answers, right?

 

[Lectrician]

Sorry - should have used a smiley I wasn't being abusive