Motorhome or Caravan on EHU at Home

UPDATE

I am pleased to say that I have received a prompt and well considered reply from the Club’s technical department on this subject.

The Club are aware of the issues involved and in the past have discussed them with the industry trade association, the National Caravan Council. Although the situation I have described above can occur, the instances are rare and require a combination of adverse circumstances for any problems to arise.  It is far more important to have a caravan which is designed, built and maintained to the appropriate regulations in conjunction with good hook-up leads and a sound house wiring system.

It is also difficult for the average person to determine what system their house is wired to, plus the not inconsiderable risk that they may attempt DIY solutions which result in a more unsafe installation than the problem they are trying to solve. 

Personally I am not aware of any simple solutions anyway and know that when you look at electrical safety statistics there have been serious accidents caused by private individuals attempting to fix things – connecting the earth to the live in a 13 amp plug for example!

I agree with the Club’s advice and it is good to know that the issues at least are acknowledged even if there is no simple remedy.

Exellent discussion , earth spikes ,wait till they put one through underground pipes ( used to happen ) on a tangent ,built extension to bungalow ,did all the work ,then sparky comes to sign it off . earfh bonding when you use plastic pipes ? he didnt get it either

hitchglitch - good to know technical dept replied promptly. 

I once worked for a small company which supplied power generating equipment for fitting into vehicles -frequently Land Rovers.  We also supplied 440v.a.c. units for fitting in ice-cream vans.  One day, and owner of a fleet of these van phoned me to say one unit was faulty - the freezer kept tripping out.  He said it was the unit, because when they isolated the built-in power unit and ran a 440-volt supply from the depot, the freezer worked fine.   Then he did mention that they had to jump on and off the vehicle or they got a shock.    Ah! I then asked if they also had an earth cable connected.  No, just the three live cables.  I told the owner to switch off the supply, connect an earth cable, then try the freezer again.  As I expected, the MCB dropped out.

With all the older caravans around, and many reliant solely on DIY maintenance, I do wonder how we rarely, if ever, hear of campers occasionally getting a "jolt" when hooked up on campsites.

"I do wonder how we rarely, if ever, hear of campers occasionally getting a "jolt" when hooked up on campsites"

Every EHU pillar has its own earth spike on a campsite. But make sure your cable is in proper working order!

Just to confirm the comments from Hitchglitch and what the club has said.

From an instructor running an 18th edition wiring regs course. The regs would not allow a TNC-S earthing system for a camp site but do not have any special requirements for hooking up at home. They DO have requirements for electric vehicle charge points at home. 

Fiddling with home grown earth rods or similar is unlikely to improve anything and unless properly tested could be a bigger risk than the potential, but extremely unlikely risk of failure in the combined N and E in a TNC-S system. 

So I for one will change nothing and connect up at home as normal.

Mike

Correct. As to what action you wish to take that is entirely up to the individual.

We were at a site near Shrewsbury with a new caravan when I decided to give it a clean. I was wearing wellies and had no issues at first. I then got out a step ladder to clean the top and climbed up holding on to the ladder, when I also put my hand on part of the van I got a shock, mild but still a shock. First I thought it was static but doing the same thing again produced another shock. I had an electric meter so I checked between the van and the ladder and there was a voltage, can't remember how much now. We stood clear of the van and checked the electric post and noticed it had been bashed. Called out the park owner and he immediately called in his Electrician. He found that the post had been hit by someone and it had dislodged the earth strap from the earth spike, after repair the van was at the same potential as the earth, no more shocks.

Sounds quite dangerous.