TT system converted to PME - Earth rod query

[Engineer54]

What value ZE do you regard as suitable for a TT then and why?

Yes of course I have informed the customer of this - his energy supplier is making a visit on Monday to see if the farmhouse is suitable fro an upgrade to 100A. Sorry if I didn't make that clear boss, it'll just have to come out of my wages I guess.

How about you tell me, you are after all the electrician on the job!! Oh and the correct term is Ra, NOT Ze when referring to a TT system.

Not sure what an upgrade to 100A has to do with anything, perhaps you can explain??

 

[Risteard]

In many countries on the Continent it's actually a rule to have a local earth rod

Not just on the Continent. In the south of Ireland ETCI Rules require an earth electrode connected to the MET on a TN-C-S (aka "Neutralised") installation.

 

[Engineer54]

Not just on the Continent. In the south of Ireland ETCI Rules require an earth electrode connected to the MET on a TN-C-S (aka "Neutralised") installation.

That makes a good deal of sense to me, why it isn't the same in the UK i really don't know.
I wonder why no-one from Southern Ireland here, has ever mentioned this requirement. This is the first time i've heard of this requirement in Southern Ireland....

 

[davesparks]

I wonder why no-one from Southern Ireland here, has ever mentioned this requirement. This is the first time i've heard of this requirement in Southern Ireland....

I've mentioned it a few times on similar threads, and I learned about it on here!

 

[Knobhead]

Not just on the Continent. In the south of Ireland ETCI Rules require an earth electrode connected to the MET on a TN-C-S (aka "Neutralised") installation.

A while ago I asked Marvo about supplies in SA, he sent me some pictures of a service head.

Some interesting features to it, mainly the concentric being locally earth. I’ll leave it to him to post them

 

[HandySparks]

I've mentioned it a few times on similar threads, and I learned about it on here!

Possibly this conversation between Risteard and E54. :biggrin:

http://www.electriciansforums.co.uk...l-regulations/61727-tn-c-s-tt.html#post585894

 

[Knobhead]

A while ago I asked Marvo about supplies in SA, he sent me some pictures of a service head.

Some interesting features to it, mainly the concentric being locally earth. I’ll leave it to him to post them

From Marvo:
“I took the photos specially for you or maybe for Eng to show you the earthing arrangement at my house which is TNCS on a 60Amp 16mm concentric cable with a local rod at the point of supply.”

 

[GEOFF S]

Not just on the Continent. In the south of Ireland ETCI Rules require an earth electrode connected to the MET on a TN-C-S (aka "Neutralised") installation.

The Yanks employ a similar earthing system to the above too.

Cheers

 

[SPARTYKUS]

Not just on the Continent. In the south of Ireland ETCI Rules require an earth electrode connected to the MET on a TN-C-S (aka "Neutralised") installation.

...perhaps to safeguard against nasties happening when the laws of physics changed back in the sixties and it became a great idea to just have two conductors to each house because that works.

or...was it cheaper maybe...? Hang on......

 

[Knobhead]

Some of the early Australian distribution systems were ingenious when it came to saving money. A single MV conductor feeding a transformer and use earth as the return. Just how it worked when it was exceptionally dry I don’t know but I’d be very wary of approaching a transformer pole.

 

[davesparks]

She'll be right mate!