Its my understanding that caravan sites should be TT if on Hook up points, however on a site that a previous electrician has first fixed but not second fix due to a fallout, anyhow I said that in my opinion they should be TT at hook up point not at the feed point. Customer agrees but previous spark has done over 500 where there TT at the three phase distribution board. Then he has used either a 3 core or a two core and armoured sheath. The caravans range from metal static, tow behind or some tent pitches. I've had this issue before but don't want to offer incorrect advise especially when he's had so many done
The hook-ups themselves should be TT but the distribution circuits can use the suppliers earth as long as the earthing arrangements are kept separate. The distribution circuits could also be TT but then you've got the added headache of earth fault protection due to disconnection times etc if TN EFLI values cant be achieved/proven stable.
Thats what the other electrician has done TT all distribution circuits. I haven texted it yet so we will see what the results are like. Just wanted back op or clarification that I'm correct or incorrect I. Saying hook up points should be individual tt
No the hook up points don't have to be individually TT'd they could be done in parallel for example. multiple rods throughout the installation is going to achieve a better Ra than one 4ft twig banged In at each hook up.
If more than one rod is used, the spacing between them should exceed the depth to which they are driven, by a factor of 2 to 3.
What do you do with the earth from the supply in pic three there Lee ? It shows it connected at the incoming board, but nowhere on the pitch supply pillar.
As its caravan pitches its almost certainly going to be installed using SWA. If the armour is used as the CPC any you was glanding in to a metal enclosure you could use a gland like this with an insulated section to separate it or in to a insulated adaptable box and make it safe in there.
Cheers Lee, I just wondered what was the point of connecting the earth at the incoming board if the earth isn't connected at the other end.
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