Is this TN-C-S or TN-C, also earth bonding size.

[mR__Slug]

I've tried to understand one way or another but this seems to be connected to the DNO fuse/cutout, and then loops down (out of sight) and comes back up to connect to the outer sheath.

The bonding looks like 6mm^2. And the connection point looks like that's the max it will take. As I understand it, TN-C-S needs 10mm^2 so TN-S?

 

[davesparks]

It's impossible to tell from looking at it.

It would have originally been TNS and the original cutout has been replaced with that one.
But those cutouts have a removable N-E link, so it could still be TNS if the link has been removed or it may have been left in place to convert it to TNCS.

 

[mR__Slug]

Thanks, though not the answer i wanted

I had a man out to change the meter, should have asked him. If the DNO fuse was 1/4" to the right, he could have changed it. Got to sort out the door for clearance.

There are two issues here. First I need another bond to the gas. From the CU? Or split the CU wire and a terminal block for the additional gas bond. Then we have the size issue. My house is in the process of being renovated, so now would be a good time to pull a wire.

It's an Earth Loop Impedance Tester that'll allow me to measure and find out? Ze reading or or something can be used to work out what I have.

I want to update the CU to 18th with RCBOs at some point so hoped I could sort bonding first.