To earth or not to earth

[LC2]

OK. had a question yesterday about main earth regs. Please can some1 answer something for me as i am a little confused. Stacked consumer units main one and economy 7 one below it. The main one has a 16mm main earth (all ok so far) the cheap rate one has NO main earth (two storage heaters and an immersion on it, 3 circuits total) I really do not understand why this is not earthed, please someone explain (and yes i am only 4 months into my career as a sparky so very green at the moment)

 

[Guest123]

Hey.

When you say stacked, are they one unit with over and under din-rails, or are they two seperate C.U's just one on top of the other?? Also if it is one unit is it metalclad?

 

[Spudnik]

Long and short of it is it SHOULD be earthed.

As a rule 16mm. Same as main CU.

 

[LC2]

OK its two seperate C.U s with seperate meter tails stacked one on top of the other.

Is there any reason why this was not earthed in the first place (installation is roughly 25 years old)

 

[Guest123]

Are you sure there's definately no earth?, because there 100% should be.

 

[LC2]

yep certain of it, my partner had a look at the job B4 me and said that there was but I had a look 2day and NO EARTH.

 

[Spudnik]

yep certain of it, my partner had a look at the job B4 me and said that there was but I had a look 2day and NO EARTH.

First job tomorrow then is to get it earthed!

No idea why is wasnt tho.

 

[Guest123]

Best get one in there then!!!!! 16mm as said.

 

[LC2]

OK cool thought i must have missed something when learning all this stuff, thought maybe there was a reason why this was left like this..

 

[Guest123]

Think of it like a car without brakes!!!!!!! works absolutely fine, the minute thers a problem you'll get hurt

 

[LC2]

yep true enough, I just vaguely remember something about reasons for not earthing in some situations. (couldn't see that this was one of them though)

 

[Guest123]

Er no, definately not.

Some area's in hospitals aren't earthed - x-ray suites, operating theaters and the like but there are many other measures in place to compensate for this.

Cheers