Correct earthing method for house?

[Trevreg]

See attached photo of my new 3 phase supply at my house. Tails supply a Schneider 3ph board. Sparky is in two minds about the correct earthing method as the powergrid haven't supplied an earth. What's the correct method?

 

[MDJ]

I would ask the supplier why they didn't supply a earth, it looks like you may have to TT the system, but the Electrician should at least enquire about this, also the earth at the bottom looks pretty small so I am assuming it goes to a rod and not the DB, My eyes are not great these days mind but the earth is 6mm2 at best to my eyes

 

[R-fur]

As MDJ said. The DNO are not obliged to supply an earth, they normally do but sometimes they don't if they think their system is not suitable or if they think the installation is not suitable for TNCS.

 

[Rockingit]

Looks like there's phase reversal going on there as well to correct (one hopes) miswired conductors inside the head??

 

[DefyG]

Is this a new installation as pencilled labels behind tails from cutout - R Y R N?? Usually marked - L1,L2,L3+N (SSE do).

 

[Rockingit]

Is this a new installation as pencilled labels behind tails from cutout - R Y R N?? Usually marked - L1,L2,L3+N (SSE do).

I spotted that as well and wondered what that is all about - R Y B, maybe, if the fitter was proper old school, but that makes no sense at all.

 

[MDJ]

I spotted that as well and wondered what that is all about - R Y B, maybe, if the fitter was proper old school, but that makes no sense at all.

I agree, confused me as well, very strange

 

[westward10]

Why the separate blocks ?

 

[Julie.]

Why the separate blocks ?

I assume the electrician fitted the cu etc and terminated in blocks as they didn't know what would be installed by the supplier/meter installer.

 

[westward10]

I assume the electrician fitted the cu etc and terminated in blocks as they didn't know what would be installed by the supplier/meter installer.

They don't look long enough so you have needless joints.

 

[Julie.]

To the OP

They don't look long enough so you have needless joints.

I think that was the plan, they probably expected the meter fitter to bring tails out of the meter into the blocks, not expecting an isolator to be fitted.

 

[Julie.]

To the OP, I would ask the sparky to measure the "Ze" using the neutral and a phase.

If it comes out low at 0.35ohm or so, then ask the utility for the earth - most are trying to deliver PME when they can, so might be an oversight.

If it comes out much higher then this that would be why they didn't provide an earth (they aren't actually obliged to do so), so clearly a earth has to be provided by the sparky meaning a TT system, in which case the sparky may need to redesign parts of the installation.