Temporary

[T&K]

Hi everyone,

Im currently working as an assistant site agent, but i'm hoping to begin traing to be an electrician. Ive got loads of questions and hopefully you can help. The site i'm working on has a 3 phase meter in a cupboard. There is an earth rod next to it.

- Is this a TT system?
- The sparks has connected an earth cable into the HEAD ( i think its called) Is this correct? Why is it not connected to the rod?
- there are 3 cabins 1 on its own 2 on top of each other. they have thier own earth rods, why?
- What does exporting earth mean?

Im sure you all get sick and tired ofbanswering newbies questions but i really want to learn properly, so if you can answer in 'laymens' that would be helpfull.

thanks in advance

 

[Knobhead]

The best person to ask is the electrician that connected it.

 

[T&K]

Hi Tony,

He's not on site for another month or so.

 

[kingeri]

TT systems use earth rods, but without seeing the install, it would be difficult to comment with any degree of certainty. For example, it could have previously been a TT system which has been changed over to PME (TNC-S). Or it could be a PME system but someone has not wanted to export the earth to another building so has provided an earth rod for that part of the installation. Just don't know.

 

[T&K]

Kingeri,

I'll try my best to describe it. This was all done before i started on site, a cable was jointed in the road up to a new head. a black earth cable come from this to a buried earth rod.

 

[kingeri]

Sorry. Can't be sure. Why do you want to know anyway?

 

[T&K]

iI want to learn. Can you answer any of the original questions?

 

[T&K]

The earth rod was not put in by the sparks by the way, but the service provider. So what is exporting earth?

 

[oldtimer]

If the supply is classed as a temporary installation then you have to supply your own earth via a rod as the DNO ie Scottish Power say will not supply an earth until there is a completion certificate

 

[T&K]

But the supplier has put a rod in already. In the cupboard with the meter there are 3 blue sockets with leads out to the 3 cabins. They have there own earth rods. Would this be a case of not exporting the earth. Sorry for being thick its all new to me.

 

[moddeydhoo]

sounds like tt, all d/b should have their own earth rod, mat whatever, the whole system on an rcd, sub main time delayed rcd, or rcbo

 

[oldtimer]

But the supplier has put a rod in already. In the cupboard with the meter there are 3 blue sockets with leads out to the 3 cabins. They have there own earth rods. Would this be a case of not exporting the earth. Sorry for being thick its all new to me.

Well to me this tells me that it is a temporary supply but to be honest and I dont want to insult you but yes you want to be an electrician but you need to walk before you can run so you need to learn the basics before you jump into something like this and hence why you are not picking this up

 

[T&K]

thanks oldtimer, no insult at all. Im not actually doing this work just looking at work on site and trying to understand it. Ive always thought you learn more from a practical point of view to a class room. I do read a fair bit about it though. I get TT TN-s TNc-s etc but if its temporary and a TT whats the earth rod doing? Does that just protect the DNO cable?

 

[Des 56]

thanks oldtimer, no insult at all. Im not actually doing this work just looking at work on site and trying to understand it. Ive always thought you learn more from a practical point of view to a class room. I do read a fair bit about it though. I get TT TN-s TNc-s etc but if its temporary and a TT whats the earth rod doing? Does that just protect the DNO cable?

You best get the books out and study the supply types, be they services,temporary or permanent installations, sub mains,standby,energency and final circuits etc before trying to understand the make up of the system you are viewing

Until you understand these,you are flogging a dead horse

The function of the earth rod will depend on whose rod you are describing

 

[Guest55]

iI want to learn.

that'll be college then , not asking random questions to random strangers about an installation we cant possibly see.