Caravan park installation

bks · May 12, 2014

Working in a caravan park as a full time electrician found that most of the hook up point in every single pitch got high Zs reading because of using two core SWA (average 1.7 ohms TNS earthing system). In some cases up to 31ohms because corroded SWA glands and broken SWA. if there's been used 3 core and you wouldn't have many issues with reliable earth for caravan.
now my question is; is there any Regs that contractors have to or must use three core SWA for all caravan park installation. Recently the park I work, all the caravan park installation under ground cable has been upgraded but 2core. I raised this issue to the contractor but never listened and said its fine. I know that SWA can be used as earth but no good for long term due to weather and could corroded glands and SWA then loosing earth continuity or not reliable earth. In many cases I had to replace SWA glands or re-terminate while doing EICR for those caravan.
What do you think guys using 2core SWA in caravan park and in this typical English weather?

davesparks · May 14, 2014

Poor termination is not a result of it being 2 core though is it?

If the outdoor conditions are that bad then take the SWA through a stuffing gland on the enclosure and terminate to an internally mounted gland plate/ lamppost gland plate type of thing!

Meggerman · May 14, 2014

Andiwoo said:
Well thankfully I have a good habit of checking swa connections so yes I do think I would pick it up to be honest. Also I think you misunderstood what I was saying, I know the swa has to be well terminated whether it's the main earth or not. I'm saying that you rely solely on this being a good connection because it's your only earth and I have come across a lot that have been badly corroded and poorly connected. So with 6-7 vans relying on van 1 to have a good armoured connection is not good. I have personally had 1 poor connection on van 1 which lead to there being no earth on all the other vans on this leg, I found this by having to test a van that was second to last on the line. Now if this was a 3core the chances of there being an earth on that last van is a hell of a lot higher. I'd take a copper connection inside a hook up box over the armour any day, to have both is an added bonus.

The second quote you tagged me in was actually quoted by the original poster, but to call it unnecessary copper doesn't seem quite right to me, from what I've personally seen and I think whoever got a belt off a live van and suddenly became the vans earth rod would strongly disagree with you.

Either way it's each to their own but I personally don't like the set up and would rather see an additional core or a TT point at every van. The cost on this site would be extreme as it's a very big site but safety first eh.

I agree. 3 core and having a dedicated cpc is far better. Far less likely to lose earth to vans which is most important fact and 50% less likely to lose earth connection to sheath as it has earth connected both ends by cpc core.

davesparks · May 14, 2014

And if it is installed properly with due consideration to the environment it is in then no armour connection will corrode anyway.

Meggerman · May 14, 2014

But in reality it has failed, and others do too. I earth the sheath but always use dedicated cpc. Except out to my garage where I inherited the old 2C 2.5 SWA

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Plonker 3 · May 14, 2014

davesparks said:
Poor termination is not a result of it being 2 core though is it?

If the outdoor conditions are that bad then take the SWA through a stuffing gland on the enclosure and terminate to an internally mounted gland plate/ lamppost gland plate type of thing!

You have basically described a CW gland which should have been used here anyway.