earth cable supplying tt earth spike

[ukpablo]

I have looked at table 4.2 on page 29 OSG regarding cable conductor sizes supplying earth rod, but what size generally do u use for this purpose?

i.e do u just run a 16mm everytime??

 

[sjm]

The minimum main earth conductor size for a TT system is 10mm. 16mm is over spec so therefore more than acceptable.

 

[Des 56]

The minimum main earth conductor size for a TT system is 10mm. 16mm is over spec so therefore more than acceptable.

The Chinese are buying up all the copper,so we need to go easy on its use
10mm indeed


Bearing in mind the system needs only carry 30m/amp to operate the rcd,the size of cable to carry that current can be much ,much, smaller than 10mm

10mm is good to work with though,so thats my choice

 

[telectrix]

thought 6mm, mechanically protected was ok, or am i talking krapp

 

[Des 56]

thought 6mm, mechanically protected was ok, or am i talking krapp

Not at all

 

[andekoch]

was checking the size of tt cable requirement the other day and it is 2.5mm if not subject to corrosion or mech damage other wise 10mm min if sleved copper. if memory serves me right. I used 10mm since relatively easy to work with and what I have in van.

 

[robsparky1975]

if memory serves i think it might even say 4mm2 in the regs if mechanically protected,would have to check it.

 

[robsparky1975]

blimey ande we must have been posting at the same time and its some of the same words,twillight zone

 

[sjm]

Have just checked and I stand corrected. 2.5mm protected against corrosion and mechanical damage otherwise 4mm however I always use 10mm. However as the main protective bonding conductors must not be less than 6mm I wouldn't use a smaller main earth conductor.

 

[Deleted member 19807]

I use 6mm for rod amd 10mm for bonding in case its changed to TNC-S, then the bonding is still ok.