Touched rig while standing on wet ground...Shocking!!!!!

[PTT]

Sent: 9/24/2004

When my 1975 Itasca 27 is hooked up to city power and it has rained or the ground is wet I get a tingle/shock when I touch any metal on the motorhome!  Where should I start looking for the cause?  Thanks!

[mightybooboo]

Sent: 9/24/2004

You have a bad ground.Check your outlet you are plugging into with a tester asap,make sure your Winny pigtail has a ground on it.Others will get into this deeper with you,just a quick note here.

BooBoo

[Jlogue88]

Sent: 9/24/2004

Don't pump gas when tis is happing  j.k. check grounds, check the circuit breakers. Check everything! You get stuck get an electrician  wiring is not a hobbie Just a safety precaution have all your outlets changed to g.f.i.c. or arch fault.

[Sea Hag]

Sent: 9/25/2004

You can purchase a receptacle tester at any hardware store or home center . They plug in and have three Leeds on them . their fairly cheap . and will tell you if wiring is correct to receptacles . sounds like someone cross wired something in a receptacle or main plug . a wire run might also be cut somewhere . Like stated above if you aren't comfortable or knowledgeable with  electrical wiring , get some help . it can be dangerous .  Sea Hag

[denisondc]

Sent: 10/4/2004

  You might have more than one problem too.
     First the hot side of the 115 volt circuitry is supposed to be totally isolated from the grounding wiring.    And your grounding circuit is supposed to prevent any shock.  A tingle is just a small shock.

    Also your situation isn’t very rare.   Mine did it years ago.  The hot side, (supposed to be the black wires) is connected through the things you plug into the outlets, to the neutral or return wire, (supposed to be the white wire), back to the shore power cable.

  Your ground wires would either be bare copper or have green insulation.   When you are plugged into shore power, the black wire will measure 115 volts to earth.  The neutral wire should only measure a few millivolts to earth.   The ground wire should measure maybe a few microvolts. 

   The purpose of the ground wire is to protect you from a short circuit in the black wires, an open circuit in the white wires, and something going wrong in whatever you plug into the outlets.   If there is a definite short circuit, the circuit breaker would pop open, but not if the â€"short- is a very weak one.      In much of the typical wiring in our old Winnies, the black and the white wire, along with the bare copper wire, run along together inside a plastic sheath.  This is standard house-wire for dry locations â€" NM-, Non-Metallic sheathed cable.   The National  Electrical Code would never allow this type of house-wire to be used in a wet location, because if any water gets inside the plastic sheath, it will eventually soak into any hole in the plastic insulation, and you could have a weak electrical connection between the hot wire, and the ground wire.   It would cause a weak shock.    What they require instead is UF â€" underground feeder cable.  It uses a better plastic, and all conductors are individually insulated and separated from each other by further insulation inside the sheath.    A home electrical inspector would consider anything outdoors to be a wet location.   

    So any place where that NM wire is getting damp could cause the problem you have â€" along with a poor ground connection, due to old age and corrosion.

  A problem in your 115 volt appliances could do the same thing.  The roof a.c., the fridge, the inverter, the inside of the breaker box,  could be the location of a wet spot or dirty insulation or a dirty switch.  Even a furnace or water heater could do it, if they ran off 115 volts.  Mine don’t.   Your inverter could have a weak short-circuit between its primary and secondary  wirings.  The secondary winding of the inverter provides 12 volts, and the negative side of its output is connected to the ground.   The 12 volt circuits don’t have the separate neutral wire.   

   A dirty or wet switch in your roof a.c. could be the culprit, same for the fridge.   If its one of these things you can open the circuit breakers feeding them, and seeing if the shocking ceases.    In  my case I went around tightening all of the connections inside the circuit breaker box, the outlets, the roof a.c. feed.  I even soldered the ground wires to each other where I found a wire-to-wire connection.   I found plenty of loose-ish connections, and my shocking problem stopped.   If its been really rainy though,  I can still usually tell if the RV is plugged in, by sliding my fingertips along a bare aluminum surface.   It feels like there is a tiny vibration there.

[WalterHynson1]

Sent: 10/12/2004

you have a short circuit from the neutral and ground I had a similar problem and the refrig was the problem I simply unplugged each accessories one by one until the problem disappeared also the electrical system wiring in my unit was a total mess I ripped it all out , I found rusty 115 sockets,shorted wires ect I designed a new system similar to an aircraft or boat with individual changeover switches for each circuit, all new wiring in plastic conduit along the walls, works perfect.  WCH

[RV Mech Tech]

PTT - one of the first places you can look is any outside outlets (mounted on the side of the coach body) or any outlets in the storage compartments  that may have water getting in - originally the boxes that these outlets are in were sealed from any water or moisture when they were new but over time the sealant may have cracked or fallen off and water has penetrated into the outlet and is if there is enough water it will bridge the gap between the power (black) or neutral (white) and the ground - ( I have found many of these on older coaches and some new ones that were not sealed correctly from the factory!) - all of these outlets on newer RVs are 'downstream' of GFCI outlet located inside the coach and when a problem occurs the GFCI outlet will trip shutting off the power to the outside outlet - your coach may not have a GFCI protecting that outside outlet so the power remains- this is a very dangerous situation and the reason you feel that tingle is because you have become the 'path of least resistance' for the electricity instead of the grounding circuit - since you have this problem when it rains then I would look at those outlets in those locations - you can also test to see how much voltage is present in the coach body by using a multimeter on the high voltage scale- put the negative lead of the MM (black) into the ground and touch the side of the coach with the red(positive) lead and you will get a reading - if it's full voltage (115 to 125V) then you have a short to ground (black wire is touching the metal of the coach/chassis - the circuit breaker should trip in this case but I have seen several older CBrs not trip because they are defective and new CBrs as well this is a rare case but it does happen - the electrical supply manufacture Federal-Pioneer had complete  defective CBrs and service/electrical panels for houses with a major recall - you can see this on  www.inspectapedia.com) - and if it's a partial voltage then you have the neutral touching the metal or a wet outlet as I mentioned above - this is called a  "skin test" and I use it on both new RVs during a PDI and every used coach I work on even if that is not what the RV is in the shop for - I do this as a courtesy for the customer and I have found a few that did have shorts and other problems that the owners where not aware of - there is a very good article by Cooneytoone called 'Lesson on Batteries & Other Electrical Stuff' in the 'Tech talk' subsection of the Members Articles topic and a good website to check out for additional info is www.inspectapedia.com (it's in the resource list on this website) =this is a residential contractors site but has a lot of info on electrical application- let us know what you find!    Hm?

[jkilbert]

while growing up we had a 1972 globestar tt. we had the same issue. it turned out that when the aluminum siding was screwed to the coach. they put a screw through a 110v wire...