shocking!

[oneofakind]

I have a 21 foot avion travel trailer that was converted into a motor home by 'mounting' and marrying it with a 1970 Ford E300. We are having an issue - it is shocking you when you touch it if it rains or are standing on wet ground, mostly the door handle but you can get a shock almost anywhere on the shell if it is raining - does anyone have any advice on where to begin the search for the problem or what the problem might be.

[MEXICOWANDERER]

From clay to sand, I have yet to meet terrestrial soil that did not respond to a dedicated ground stake and several gallons of water. Testing consisted of 3 repeat direct shorts line to earth through a 30 amp breaker.

I have encountered far too many marginal receptacle "grounds" that "tested" good then went open circuit with more than say a quarter-ampere applied short. I know of no effective way to thwart this - and it is definitely dangerous. I had a line to earth test circuit within Quicksilver. With a complete circuit it held the NC relay open. Loss of ground triggered a Sonalert. Alarms became such a pain down here I switched to my own ground rod.

[Testudo]

With regard to grounding:

If you are connected to a properly grounded pylon, you will be grounded (...and assuming you have a grounded electrical system in your camper ! ! ! ). BUT, always check what you are hooking up to, first! It is surprising how often I hook up to ungrounded (...or ineffectively grounded) commercial systems - - especially in the West were high ground resistance can foil the best of intentions. At least you will know that you are dealing with a bad ground and can inform the rest of your party to be cautious when handling electrical appliances.

If you are on a portable generator, you will NOT likely have a grounded system. GFCIs help in that case but are not a panacea - - caution must always be observed and everyone using the camper should be informed of the risks of handling power therein (...for example, don't use a hair dryer while standing in wet grass - duh!).

Contractor generators are meant to be grounded but this is not practical in a mobile camping situation. In practice, the results will be no different than if you are using an unbonded generator (...like a HONDA EU2000).

Electrocution is like the fifth leading cause of occupational death in the U.S. When you consider how many "experts" get killed by electricity, it is a wonder that we don't hear about more "amateurs" getting killed - - especially RVers and their 'homebrewed' systems.

Another albeit expensive solution is to put a power management device between your RV and your power source. A 30 amp Portable RV EMS device like that made by PROGRESSIVE DYNAMICS (they make a 50 amp version, too) runs about $270 on AMAZON and will detect a number of bad conditions (including the one in question) to protect you and your appliances. It WON'T CURE_ a situation like the case in point but it will protect you by shutting down the power until the problem is fixed.

[Harvey51]

It seems to me there has to also be a connection of hot to ground to put a substantial voltage on ground. Perhaps a defective load somewhere in the trailer or a misconnection in the wiring. Tripping the main breaker to prevent the hot side of the AC power from going anywhere inside should stop it. If not there has to be a hot to ground connection in the cord or wiring before the main breaker. And probably one of the other breakers will stop it so you will know where to look for the bad connection.

[road-runner]

Harvard wrote:

Hurricaner wrote:
The RV is not grounded. This is what causes hot skin 99.9 percent of the time. There may be other problems that aggravate the condition but if the RV is properly grounded you will not have hot skin.
The RV frame and skin must be connected to the service ground. Generators are a whole different ball game but when it comes to hook ups you better have a good ground.

Sam

and, because the RV chassis is not grounded, the chassis will float (due to stray capacitance) about half way between H and N IF there are no other problems excepting the open ground.

X3

[Harvard]

Hurricaner wrote:
The RV is not grounded. This is what causes hot skin 99.9 percent of the time. There may be other problems that aggravate the condition but if the RV is properly grounded you will not have hot skin.
The RV frame and skin must be connected to the service ground. Generators are a whole different ball game but when it comes to hook ups you better have a good ground.

Sam

and, because the RV chassis is not grounded, the chassis will float (due to stray capacitance) about half way between H and N IF there are no other problems excepting the open ground.

[Hurricaner]

The RV is not grounded. This is what causes hot skin 99.9 percent of the time. There may be other problems that aggravate the condition but if the RV is properly grounded you will not have hot skin.
The RV frame and skin must be connected to the service ground. Generators are a whole different ball game but when it comes to hook ups you better have a good ground.

Sam

[MEXICOWANDERER]

"Pluck your magic twanger Frogeee..."

An inductive voltage detector tester waved over interior appliances will find the culprit.

The shoe insulation scenario works great until the first rain.
Someone barefoot knocking on your door has a possiblilty of sharing the prceeds of your life with an ambulance chaser.

[Harvey51]

I wouldn't be in a big hurry to drive a grounding rod into the ground. You already survived the tingle and it won't be any worse next time unless you ground yourself better. Any decent shoe will limit the current to a few milliamps, similar to what you get from a GFCI outlet.

After trying a different cord you might want to have a helper turn on breakers one at a time until you feel the tingle to isolate the problem circuit.

[MrWizard]

Does this happen every where you go, or just now at a new camp site
Problem could be the shore connection

you possibly have a broken loose neutral unplug from shore power
You need to check the neutral and ground wires
In the breaker panel
In the connection box where the shore cord is attached
In the transfer switch (if you have one) ( do you have an on board generator )
And you Need to check continuity of neutral in the shore cord
From plug to connection box

[Testudo]

"For some reason it did NOT trip the breaker..."

Note that residential circuit breakers are NOT designed to detect polarity reversals ( hot to neutral swaps ). Standard residential circuit breakers are designed to stop OVERCURRENT !

While I highly recommend the installation of GFCI outlets in RVs, GFCIs can be 'fooled', too. A GFCI merely measures any current difference between the hot and neutral. If it detects one, it breaks the circuit before your heart can be 'toasted'. If current were to flow from hot - - through one side of your ungrounded body to the other, the GFCI would not measure a difference in current and would not trip. So if you were to plug a zip cord into a GFCI protected outlet while standing on a residential or RV floor, and touched the bare ends of that zip cord, you could be fatally shocked.

Your safety in your RV is only as good as the pylon that you are connected to. I highly recommend that RVers test the electrical source before hooking up. You'd be surprised how often there is something wrong with the voltage or with the ground.

Note that the EU series of HONDA generators (and their ilk) does not come with a neutral bond as required by OHSA for site power. You can hook up a HONDA EU series generator to power your house (with the appropriate transfer switch to prevent back feeding) and you will still have a neutral bond at one point as required by the electrical code (...that's a good thing). Some folks buy bonded contractor generators and use them with their RV. That's okay from a Code standpoint as long as your RV is not otherwise hooked up to the grid because the RV panel is always wired like a sub-panel.

For those of us with just one RV power source so that only one power device can be attached at one time, no transfer or isolation switch is needed - - there is no possibility of back-feeding. The circuit breaker panel on your RV should NOT be bonded - - think of it as a sub-panel for when it is connected to an RV park power source.

If you have created a 'floating' system, you have to be more careful in your RV as any fault or mis-wiring becomes potentially more lethal since circuit breakers might not trip in some circumstances in an unbonded system. Another good reason to add GFCI protection to your RV.

Above all, _always_ respect the NEUTRAL conductor ! It can kill you just as dead if _you_ get in series with it.

[Testudo]

I think 'Boatycall' has zeroed in on the probables.

Get an inexpensive outlet tester at HOME DEPOT or LOWES. One with a GFCI test button might be a more useful tool in the long run.



Stick this 'puppy' into any 120 volt outlet in your camper and it should quickly verify if the conditions that 'Boatycall' indicated are the problem. But FIRST, test your camper's outside power source ! I _always_ test the campground's pylon before I hook up to make sure I know what I'm dealing with ( you can get an inexpensive 20amp to 30amp plug-in adapter at any RV supply store or WALMART ).

Once you determine that you have a condition described by 'Boatycall', then, if you are not so comfortable handling electricity, you can decamp to any RV dealer who has a certified electrician who can track down the cause.

Because an RV is not usually grounded like a house, the issue could be in the main or any branch circuit. From where the power enters your camper to any fixture or outlet, you could have a polarity reversal pretty much anywhere. A multimeter and a careful process of elimination is necessary to zero in on the culprit.

[wa8yxm]

Two thigns I have had do that....
AN open ground will put the chassis and metal parts connected to it at 60 volts relative to either neutral (Which is bonded to ground elsewhere) or hot. (This is on a 30 amp RV. on a 50. it might be a different voltage or even zero, higher if plugged into 30)

This indicates an open ground. HOwever though you can measure 60 volts, or close to it, nearly no current flows.. The reasons are technical and Well. One of the many classes I took in college explained it rather well.

However another issue I've seen is a polarity reversal. For some reason it did NOT trip the breaker (I know the ground was good) but that dang trailer would knock me for a loop if I touched two metal parts INSIDE the trailer.

I finally figured out what the prior owner had done wrong and fixed it.. He was, like me, trained in electronics... But unlike me he was NOT cross trained in electrical. (Black means different things depending on which hat I'm wearing).

[SoundGuy]

oneofakind wrote:
I have a 21 foot avion travel trailer that was converted into a motor home by 'mounting' and marrying it with a 1970 Ford E300. We are having an issue - it is shocking you when you touch it if it rains or are standing on wet ground, mostly the door handle but you can get a shock almost anywhere on the shell if it is raining - does anyone have any advice on where to begin the search for the problem or what the problem might be.

Unplug the rig immediately from shore power and stop using it until the source of this issue is found. To understand why read Mike Sokol's article on hot skin, a condition that can kill you. :E

[MEXICOWANDERER]

This weird couple pulled in next to me in Zihuatanejo. Sun goes down. I notice an orangish light under their awning.

"Well, we was getting jolted. So I bought a pigtail socket and light bulb. Now I have a neat porch light that doesn't glare."

You guessed it. Clipped to the trim molding the other wire to whatever the hell he used to pound into the ground. Time to loaddum up and head on down the pike