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Sun 15 Jan, 2012 05:13 pm
Hi, Iv got a caravan hooked up to 240 mains power, we do contract earthworks and set van up for 4 weeks at a time, iv just moved to new site and we have had some rain, after rain iv gone to get into van and have gotten a shock from the van, what can cause this? Poor ground in van, leads, or power supply ground? iv checked for loose connections but havent found any as yet. The chassie is grounded to earth from the stands on the van (should blocks be put under them to stop stray current?) Id get it tested asap but we are miles from a town atm and would cost a fortune to get someone to come out. Cheers
@Jim2012,
a Dodge caravan, a camel and tent caravan, or something british I don't comprehend? (there's a lot of that lately)
sounds likely you've a short somewhere's about it....
@Rockhead,
Australian standard caravan. Tips on testing for shorts with multimeter?
@Jim2012,
Tow behind caravan, single axle
@Jim2012,
I'm mostly american, so you're spakin' greek to me.
Electricity ain't my strong suit. Isolate a circuit at a time. check for blown fuses first. if it has fuses...
@Jim2012,
so this is like a camper?
I might have some better envisionment if we can agree on terms. (I know from spanners now)
I live in a similarly constructed paradise...
@Rockhead,
Lol, No fuses mate. straint 15amp lead into van, wondering why power tirp doesnt go off when it happens. cheers for that
@Rockhead,
Yeah bud, like a camper (whatever you call em over there) basicly a trailer (tow behind off hitch/towball) on a axle
@Jim2012,
I'm with ya now, mate...
gotta be a short somewheres. does it have outlets.?
are the wires hidden behind walls, or in conduit?
( a meter would prolly show something if an electrician stumbles over this way)
I can ask my electrician (although we run different voltage set-ups than you and the limeys) when I see him next, but he knows I am outta beer, so it may be a while before I meet up with him.)
there's an Auzzie dude that comes here sometimes that is an electrician of sorts. name's wilso.
best we don't aggravate him about this, though. he frowns on DIY stuff if I remember correctly...
@Rockhead,
most wireing is in walls, so hard to test and inspect, can only inspect where i can and at outlets and lights
@Jim2012,
I would open the outlets and visually inspect them.
you might find a scorched spot or loose wire...
verra carefully, of course.
another thought...
On both my sheet metal building, and my metal dwelling, I have ground rods and such, albeit mostly for anti-lightning measures. but the main electrical box is wired to actual ground as well...
@Jim2012,
Test for how good the ground is. "Stands on the ground" doesn't mean that you have a good or sufficient ground.
If you are set up for 4 weeks at a time, it wouldn't hurt to drive a good ground rod into the ground and attach the appropriate size grounding wire to the ground rod.
Where are you getting the power from?
@Jim2012,
go to yer breaker box and start (one at a time) shutting OFF the berakers and have somebody recreate the shock experience. Thisll isolate the circuit thats causing the problem. Then (I HOPE YOU HAVE IT) take the wiring diagrams and trace that one circuit around the trailer.
DID you say that the voltage is 240? or 24?. 240 is a some kind of trailer, do you have 240v tools in there like a table saw? ABOUT your ground. Isnt the trailer mounted on a frame of box beams and isnt the hitch jack touching the earth and isnt it a heavy steel jack stand? before you try to isolate the short, try laying your safety chains on the ground and see if that doesnt help. I used to have an old camper that would do this and I nearbout tore it apart to find the shorts responsible.
@farmerman,
Quote:DID you say that the voltage is 240? or 24?. 240 is a some kind of trailer, do you have 240v tools in there like a table saw?
Most of the world, save for NA is 220/240V, Farmer.
@JTT,
If a human, upon touching the van/caravan/trailer and being in contact with earth, experiences a shock, obviously the metal parts of the van/caravan/trailer are not properly grounded.
@JTT,
but in addition, there is probably a problem somewhere else that is charging the trailer to begin with...
@Rockhead,
True, Rocky, but I can guarantee that it will never kill the trailer/caravan/van.
A house/caravan can "live" with a slow voltage leak for years. If it grows larger than slow, the breaker should tell the tale.
You can energize a metal piece of a caravan just the same as you can energize copper wire. The difference is that you never know when the errant connection becomes capable of allowing the full amperage to flow and a human being is all too often a one time tester and then it's shot and you gotta get another one.
@Jim2012,
If it was a one time occurance, it might really be static electricity this time. Do you routinely ground the thing when it is set up? Recall that aircraft have an attachment for a ground line between ship and fuel nozzle for just this reason.
@roger,
Quote:Recall that aircraft have an attachment for a ground line between ship and fuel nozzle for just this reason.
I sure may be wrong about this but isn't that because of the build up of static electricity resulting from fuel flow, Roger?