cabin wiring

[aaelectric]

Evening all,
quick one i dont normally do. had a look at a porter cabin in a waste land, there were around 3 spread over 100m2. Supply coming in to the site is a tncs then this feeds meters and a small DB supplying the cabin. cabin is concreted in. so would this count as a permenant site. the earth from the 16mm swa is being used in the cabin db which has a 30ma rcd main switch. water is plastic pipes. does this need an earth rod also. steel feet have been earthed to cabin db. they want to add some lighting but just wanted to make sure as i thought i had to be tt.

 

[44ALLAN]

. water is plastic pipes. does this need an earth rod also.

your kidding right?

 

[aaelectric]

no i meant does the cabin need a earth rod aswell as the supply earth.

 

[micknew]

Windup or a DIYer for sure.

 

[44ALLAN]

no i meant does the cabin need a earth rod aswell as the supply earth.

Sorry mate but 100 m2 is the size of my back garden...........10 x 10 metres hardly 'waste land' !!
3 porta cabins in that area would fill it to be honest?

Why would you tt it if tncs is already there?

 

[aaelectric]

Ok maybe its a bigger not to good with sizes. Well the only reason i ask is i thought you could not supply caravans and similar by tncs so would needs its own tt system. Thats all im asking why woukd i be a diyer?

 

[aaelectric]

why is this a windup. as stated i have never done before so its good to ask and there is SOME people happy to help that have experi

 

[aaelectric]

why is this a windup. as stated i have never done before so its good to ask and there is SOME people happy to help that have experince in this part of the industry

 

[Engineer54]

Evening all,
quick one i dont normally do. had a look at a porter cabin in a waste land, there were around 3 spread over 100m2. Supply coming in to the site is a tncs then this feeds meters and a small DB supplying the cabin. cabin is concreted in. so would this count as a permenant site. the earth from the 16mm swa is being used in the cabin db which has a 30ma rcd main switch. water is plastic pipes. does this need an earth rod also. steel feet have been earthed to cabin db. they want to add some lighting but just wanted to make sure as i thought i had to be tt.

Seen porta cabins that have been in service for 30 odd years or more on the same plot. No it doesn't need an additional earth rod, but it wouldn't be a bad thing to do either, compulsory in many European countries. Pretty pointless though, if you're thinking in terms of a 100/200 ohm Ra value...

 

[polo1]

If you are considering taking power from the portacabin with the existing intake, out to other remote cabins, then this would probably count as "exporting" PME, in which case (as I understand it) the other portacabins should not take their earth from the main intake, but be TT'd. Search for exporting earth on here - lots of threads and competing opinions.

 

[Engineer54]

If you are considering taking power from the portacabin with the existing intake, out to other remote cabins, then this would probably count as "exporting" PME, in which case (as I understand it) the other portacabins should not take their earth from the main intake, but be TT'd. Search for exporting earth on here - lots of threads and competing opinions.

You don't export an earthing system of any type, you are extending it!

So please explain why you can't extend a PME's Equipotential Zone. Obviously you haven't read any of the the threads you are suggesting that the OP finds and reads!! lol!!

 

[aaelectric]

So if the cabin is being supplied direct from the services via a 50amp mcb you would not count as exporting? Also would it be a permanant installation? There is a 30ma rcd main switch at cabin db. Only 1 ring & a few radials for heaters & lights

 

[44ALLAN]

C'mon mate.....................'you would not count as exporting' is not exactly bgb speak is it fgs?

Check the site out and look for PME/TNCS supplies and 'extending' the zone.................it's all there and agreed it can be quite involved.....................sizing bonding conductors and extraneous conductive parts etc etc..........lol

Then come back with your questions and these guys will help believe me................enjoy