Chassis live when charger/ehu on

[herald_400rl]

At a site in the peaks for a couple nights, sat round the back of the van for the shade with the dog and (don't know why) I touch the towbar and there's a numbing feeling like a small voltage or earth leak of some kind.
Turned 240v off and it goes away (12v on) any ideas where to start? Could it be the site has an earthing issue with the ehu? Or are we so close that the earth rod near connected to the sites ehu is making me complete a circuit highlighting a loose wire somewhere on the MH? We are about 3m away.

 

[herald_400rl]

We are back home now and MH back on the house socket, no tingling anywhere to be found.
I will test continuity on earth of my hookup lead and invest in a socket tester, would the fact its fine at home indicate the site was likely at fault or is this no indication at all?
We have very recently had a rewire and the trips in the consumer unit here are all (I think the term is) RCBOs where each has its own test button for each circuit?

 

[The Artilleryman]

We have very recently had a rewire and the trips in the consumer unit here are all (I think the term is) RCBOs where each has its own test button for each circuit?

Best setup you can get in my opinion.
Did mine early last year, only slight down side is testing to see if it's overload or earth fault, when it trips.

 

[Bodoge]

We are back home now and MH back on the house socket, no tingling anywhere to be found.
I will test continuity on earth of my hookup lead and invest in a socket tester, would the fact its fine at home indicate the site was likely at fault or is this no indication at all?
We have very recently had a rewire and the trips in the consumer unit here are all (I think the term is) RCBOs where each has its own test button for each circuit?

Likely that the hookup you were using has a poor earth, the fact that your RCBO didn't pop indicates this. It may be worthwhile checking all terminations of your lead/s , plugs and sockets as any corrosion can cause a faulty path. Having said the likely cause doesn't necessarily mean the whole site is the same, probably just the post you hooked up to.

 

[The Artilleryman]

Likely that the hookup you were using has a poor earth, the fact that your RCBO didn't pop indicates this. It may be worthwhile checking all terminations of your lead/s , plugs and sockets as any corrosion can cause a faulty path. Having said the likely cause doesn't necessarily mean the whole site is the same, probably just the post you hooked up to.

I think he means the house has RCBO's.

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[Bodoge]

I think he means the house has RCBO's.

Yes I did, during this thread they are the first and only ones mentioned.

 

[herald_400rl]

Yes I did, during this thread they are the first and only ones mentioned.

Yes the MH has one with fault tolerance, RCD? And then just current trips, MCB?
Someone who knows will read and laugh.

 

[Bodoge]

Yes the MH has one with fault tolerance, RCD? And then just current trips, MCB?
Someone who knows will read and laugh.

I know, I'm not laughing. Pre Rcbo's you probably had a rewireable fuse box or similar in you home, and replaced it. I assume its to current regs ie, consumer unit is metal. The mcb and rcd arrangements found on most sites are probably compliant with the regs under which they were installed, current regs are not retrospective.
Getting back to your original post, do you have an on board transformer, often guilty of earth leakage or done anymore during the winter where cables may be pinched or clamped.
Just thought today whilst doing remedials on my MH.

 

[herald_400rl]

I know, I'm not laughing. Pre Rcbo's you probably had a rewireable fuse box or similar in you home, and replaced it. I assume its to current regs ie, consumer unit is metal. The mcb and rcd arrangements found on most sites are probably compliant with the regs under which they were installed, current regs are not retrospective.
Getting back to your original post, do you have an on board transformer, often guilty of earth leakage or done anymore during the winter where cables may be pinched or clamped.
Just thought today whilst doing remedials on my MH.

What would the transformer do? The ehu comes in under the seat then makes its way up to a panel which has a rcd and 3 mcbs (if that's what they are!). From there I have a red switch which says charger, presume this will turn 240v into 14ish?
Regarding the house, it was black boxes with wire in for each circuit (we went from 5 circuits to about 11). I have a certificate from the electrician, as a mortal I assume this means its current!

 

[pappajohn]

The tingle may well be static which would normally be sent to earth, if the earth wasn't disconnected. We are not talking about a serious shock here.
No reason to assume any fault other than the lack of an earth

Static is an instant discharge.
If you look at it discharge in the dark you'll see the spark between your finger and whatever you earth to.

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[herald_400rl]

It wasn't static, it was like holding a 9v battery to your tongue (how else do you know if they're dead?) but sustained and on your finger... or I suppose any other body part you placed upon it.

 

[herald_400rl]

OK so at the site this weekend same issue. Took multimeter with me and started testing continuity, earth continuity all the way through to the van electrics and then... nothing. Broken earth somewhere. Nothing on the earth bar. Took the connector off that comes from the external ehu point to the internal van board and found my prize.
Attached to the block and the polarity light doesn't illuminate now (thought it was normal to be on, but it isn't) and tingle gone. Dodged a bullet I think.

 

[Bodoge]

OK so at the site this weekend same issue. Took multimeter with me and started testing continuity, earth continuity all the way through to the van electrics and then... nothing. Broken earth somewhere. Nothing on the earth bar. Took the connector off that comes from the external ehu point to the internal van board and found my prize.
Attached to the block and the polarity light doesn't illuminate now (thought it was normal to be on, but it isn't) and tingle gone. Dodged a bullet I think.View attachment 780108

Good that you've solved your tingly problem. When you next have the opportunity discard the black plastic encapsulated connector block for either a bakelite insulated or a porcelain connector. I have seen more than one of your connectors where the insulation has melted, also it would be better if the connector was fixed to adjacent timber and a cable clip each side of connector, it will cut down on cables becoming loose, after screwing down terminals give cables a little tug to check tightness, good electrical practice.

 

[Davecrawf]

Good advice, especially as wires and things need to be more secure in a moving object, such as a motorhome.

 

[TravellingSmurff]

OK so at the site this weekend same issue. Took multimeter with me and started testing continuity, earth continuity all the way through to the van electrics and then... nothing. Broken earth somewhere. Nothing on the earth bar. Took the connector off that comes from the external ehu point to the internal van board and found my prize.
Attached to the block and the polarity light doesn't illuminate now (thought it was normal to be on, but it isn't) and tingle gone. Dodged a bullet I think.View attachment 780108

Thanks for reporting your results. I have the exact same issue away in France this weekend. Back home now and will start testing everything later. Just a thought, why would you not feel the electric shock when at home EHU?

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[herald_400rl]

Thanks for reporting your results. I have the exact same issue away in France this weekend. Back home now and will start testing everything later. Just a thought, why would you not feel the electric shock when at home EHU?

It wasn't on grass. That's the only thing I can surmise. Slightly damp grass would carry the leccy better.

 

[Bodoge]

Thanks for reporting your results. I have the exact same issue away in France this weekend. Back home now and will start testing everything later. Just a thought, why would you not feel the electric shock when at home EHU?

When any EHU gives you a good earth then any stray voltage has a path to ground and in doing so the tingling stops. You feel the tingling sensation when the EHU earth is inadequate or there is an internal break in the cable continuity and you become the earth path to ground and in doing so complete the circuit. Or maybe at home the apparatus causing the earth leakage wasn't switched on, there could be other reasons, like rubber bottom shoes etc.