Question for the Electric Experts

[Fla._Deadheader]

  Our computer Guru lives in a mobile home. He had minimal damage from the storm. Tin roof on the addition lifted a bit and water blew in under it, soaking one wall and 2 sections of ceiling.

  Since the storm, the whole metal frame of the trailer is energized.???  I took a wall outlet loose from the box, thinking it MIGHT have had water accumulate in it. It was dry. When I put it back into the wall box, I had 1 knee on the carpet, on the concrete floor. I grabbed the outlet by the ears where the screws go to fasten it to the box, and I got zapped ???

  Today, during the monsoon, Ed was standing on the aluminum ladder against the outside wall. It is vinyl siding over aluminum siding. He touched the aluminum gutter while trying to tape over a window with visqueen, and HE got zapped.

  I have done most everything regarding electricity, but, this one has me stumped. I am thinking broken ground, but, would that make the metal structure hot ???  Any ideas ???

   You definitely don't want to go barefoot inside and touch something. Even the ceiling fan pull chain is hot ??? ???

[Jeff]

Sounds like reversed polarity.  On the old travel trailers if you used a power cord without ground and put the power plug in upside down you would electrify the trailer. Grab a door knob and get a jolt.

[Fla._Deadheader]

Well, that's what's happened, since the big power outage. How does one cure it ???  Doesn't make sense to me, but, Y'all know how I am.  : : ;D ;D

[Jeff]

You can get reversed polarity from a damaged electrical appliance, or perhaps an improperly installed outlet. Or perhaps something that your favorite utility man didnt do quite right.

[DonE911]

Did he re-rig the power box to run off generator??  If not I'd go with the broken ground but the breaker should be tripping...  did it do the same after the maine breaker was turned off??

[Furby]

My brother was in the process of buying his house and had the papers singed but was waiting to close. On a whim one late night, he took a detour and drove past the place on his way home. The security light over the garage that is always on was flickering. He pulled into the drive and noticed sparks at different places on the building and also felt the wall which was very warm to the touch.
Fire department came out and pulled the meter.

Anyways, try pulling the meter and reinstalling it (or get someone to do it). Did the power panel get wet? Is the insulation on any of the wires wet?

Yep Jeff, old electric stoves would do that.  ;)

[Fla._Deadheader]

   No generator and no breaker tripping. That's whats throwing me. ???  Wires could be wet from insulation, but, that doesn't seem to be whats happening. Never heard of reverse polarity in a 120V single phase circuit ??? That is usually in a 3 phase circuit, I think ???

  I'm gonna start tripping 1 breaker at a time and see if I can isolate the problem. If not, that would only leave the broken ground or FP&L power problem, right ??? ???

[DonE911]

I would think so.... I'd start with the 220 breakers...  weird...  like to hear what happens... good info to remember in case it pops up again 20 years from now...

[Buzz-sawyer]

Harold
I have seen the same situation before.It was a house trailer, and it had a new electrical service installed.
The trouble was, the copper coated grounding rod, was not installed.I noticed the problem, after dark, when the metal steps shot a blue spark 3-4 of an inch to the aluminum sidding.
I believe it's a ground problem for you.

[Norm]

I'd go with turning off one breaker at a time to isolate the problem, he may have a problem with the neutral line. Check it on the problem circuit for continuity to the service box. If it isn't that I'd get FPL out as soon as possible.

[Fla._Deadheader]

  So far, i'm looking at a ground problem as the easiest thing to check. Neutral and ground, same-same. Only problem with that is, this unit has galv. tie down straps. Why doesn't THAT bleed off the electricity ???

[DonE911]

How much water are the grounding straps standing in??? I don't think I'd be checking them bad boys tonight...specially since we just got another 4 inches of rain today/tonight.  Just has to be ground issue... FPL may have messed up if his hotleg was completely down...

[Fla._Deadheader]

  His power never went off ??? One of the very few that had it full time.???

[J_T]

All ground systems go back to the elec.Co system . I wonder about their conection ??? Also the reverse polarity that was menchoned .We were building a house once and wiring it too.To test we ran a extion cord 110 to the breaker box then jumped to the other buss bar  and as Jeff said wired the plug bk wire on large blade or silver screw and white on small blade or gold screw and for some reason the metal duct work became hot We almost got a man killed.Even lamp cord has marked polarity wiring look at any cheap lamp cord one side is plain one ribbed or with wrighting on it .Even though ground and netural end at the same place they serve  two different purpoeses.The hot on a light bulb is in the center  it will work but is not good putting the hot on the threads another reverse polarity , Sorry I got carried away

[beenthere]

I guess I would be looking at a hot wire that is 'feeding' (touching) the frame through a break in the insulation enough to energize the trailer frame. Either that, or the hot line wrongly hooked to the neutral side of an outlet or light that is plugged in, and that being where the 'doorknobs' are getting voltage. Maybe just a wet outlet too, with a handful of spider webs in there to keep it wet. I have a 'hot' fluorescent light when the two-prong cord is plugged in backwards (similar to what Jeff explained earlier), such that the hot line is on the wrong wire. One reason for correctly wired three-prong plugs.

For one thing, isolating the circuit and putting a ground fault interupter on that circuit will trip it anytime someone touches it. If your getting a shock, then it comes from the hot side somewhere, IMO.  

Reverse polarity seems only a possibility if it was DC, but not AC single phase. That make sense?

But the one-at-a-time isolation of the breakers should help narrow down the search. Then go to each appliance or outlet on that circuit and isolate them as well. Figure out how to use a voltmeter or a test light to check the problem, as getting a shock each time might be too much 'illumination' for the system.  ;D

[Buzz-sawyer]

Well. the trailer I mentioned had the tongue settining on the ground and so was part of the frame........ :

[Fla._Deadheader]

  JT, I follow what ya said. Earlier I goofed and was thinking Rotation NOT polarity.

[J_T]

Beenthare you proved reverse polarity will get you with ac current your light fixture ?? Is the reason recptals have silver screw and gold screw .Fd is the voltage on any rec's wild  ???

[J_T]

Fd if the wind shook the netural wire on the high wires it can get weird too. Would you beleive a bad netural will start a fire quicker than a hot ???

[Fla._Deadheader]

J_T, haven't checked. We were more concerned with the water pouring from the ceiling. We put some Cypress boards up to the sheetrock and screwed them fast, so the ceiling would not come down. Then we got to talking about the electric problem, while it was pouring outside. The ground is saturated here and a shorted out flashlight would probably stand yer hair up. ;D ;D

[J_T]

Would not sleep thare with out 50 zillion smoke dectors :(

[etat]

When I wired my house I bought one a them little plug in checkers that's got the lights on it that's  supposed to check for reverse polarity and check the ground.  I actually found one of the plug in's in my house wired incorrectly with it.  I had the white wires on the brass screws and the black wires on the silver screws.  Guess i went color blind for a minute.

[Fla._Deadheader]

 Ha, never heard of one of them things. Guess I gotta go to gulp, Lowe's.

[rbarshaw]

I've had the same problem in a mobile home where the metal siding had been damaged and cut into a hot wire maKING THE HOLE STRUCTURE 120VAC to ground, gets kind of painful. Had to trip breakers one at a time till the voltage to ground went away, checked with a voltmeter from metal siding to ground, then had to dig thru the walls till I found the problem.
  If the roof was lifted and it's metal and power wires run up there like most mobile homes, that's a good place to start,

[Fla._Deadheader]

It's on an addition, and the tin roof just raised on one side, not a lot, though. Rain blew in under the tin. Why won't the breaker trip ???

[J_T]

Fd it won't check them lights .If it is that wet could be running every thing wild . With out a lowes meter take a cheep tester go small slot to center hole should read then wide slot to same center hole no read ok I can't find two tools same day :D :D

[VA-Sawyer]

FDH,
Is the service overhead or underground ?  If overhead, it sounds like you have lost the neutral going back to the transformer. ( Also possible but less likely with underground service. ) If the ground rod doesn't have an excellent connection to earth, then the neutral can float to a voltage well above neutral. Some of the 115 circuits may have high or low voltage depending on each ones load. Shirleys sister had that happen here a few months ago. I found the problem when I noticed one of the feeder lines was broken and hanging in the tree. It smoked a few appliances in the house before we got it figured out. All of the 240 V stuff worked OK it was the 110V stuff that had problems.
VA-Sawyer

[etat]

Them little thingies don't cost but a few dollars or so.  They also check for an open ground.  Something along that line some where is probably why yer breakers ain't tripping, unless you've got a bad breaker which is not unheard of.  

[J_T]

It's on an addition, and the tin roof just raised on one side, not a lot, though. Rain blew in under the tin. Why won't the breaker trip ???

Elect takes path of least resistance . Know why those rec are in boxes? To contain a fire Takes a bunch to trip a breaker seen a wire burn niceley never trip till a direct short . I pefer  fuzes but I got breakers .

[rbarshaw]

The breaker won't trip with only one side of the power line touching the metal siding/roof, have to have both sides or one side and ground touching to provide a path for current to flow. if you get a tingle off it, that's much less than 0.1 amps of current flowing thru your body and the breaker is rated for several amps prior to triping.

[trim4u2nv]

I have seen this problem before when the bonding between the breaker box and the water pipe is broken.  Or when the bond between the breaker box and the ground rod is broken.  You can test individual outlets with a extension cord ground fault interruptor usually about 3 ft long with a ground fault device between a male and female plug.  I think I paid about $22 for mine at home depot.  I got mine after we almost got electrocuted by a bad sump pump.

[jgoodhart]

Does he have any floresent lights with ballasts? If a ballast is going bad it will do as what you are describing.

[Furby]

When ya get one of them outlet checkers, also pick up one of those AC checkers. 5-10$ and it tells ya when there is current in the line just by putting the end close to the line. REAL handy little tool, and could save your butt!  ;)
Note: It works through the insulation on the line, but I found on some really old lines the insulation is too thick or something. Conduit may or may not mess it up as well.

[etat]

3prong tester


1-RED 2-YELLOW 3-YELLOW

Open Ground = Light 2 ON

Open Neutral = Light 3 ON

Open Hot = No Lights

Hot/Ground Reversed = Light 1 and Light 3 ON

Hot/Neutral Reversed = Light 1 and Light 2 ON

Correct Wiring = Light 2 and Light 3 ON

[Old_Town]

It's on an addition, and the tin roof just raised on one side, not a lot, though. Rain blew in under the tin. Why won't the breaker trip ???

It sounds to me like the system is not properly grounded. On mobile homes the frame as well as the the equipment grounds in the panel must be bonded to a secure ground, ie ground rod, grounding grid, etc and better with a secondary ground. In the case the primary or incoming neutral from the power company is open or "high resistant" dangerous current could feed back throughout the ungrounded system.

I would do the following:

visibly inspect the grounding system (look for a ground rod. 5/8"X8' would be best)

Check all grounding connections (look for loose,corroded connections)

Check for grounding conductor in panel (should be #6 copper)

Check trailer frame for grounding device.

Have power company check "secondary connections" to assure a solid neutral connection.

When the trailer is properly grounded a short circuit condition will likely arise and the damaged circuit can be found and repaired as indicated by a tripping breaker.

The breaker is not tripping now because it is not a "short circuit" but rather a high resistant circuit that does not supply ample overcurrent to trip the breaker.

I hope this helps

T

[Gilman]

Per Old Towns comment, you might want to feel the breakers.  If one is warm and there doesn't appear to be much load on it, that might be a place to start.

Good luck

[Jason_WI]

Hook a copper wire to the energized part of the trailer and then ground that to the ground rod or to the metal frame of the breaker box, the breaker should trip if you have a dead short and then you will know where to look.  I am betting that a nail from installing the new siding sliced through the insulation in an outlet wire in the wall somewhere and now that it got wet is causin all of this stray voltage.

If you have a local Harbor Freight near by pick up a cheap Digital Multimeter. There is one that is 5 bux. You can use it to check how much potential you have on your sideing and gutters.

Don't take a leak off of your back porch standing barefooted till you find your problem

Jason

[Fla._Deadheader]

  All great input from you guys, as always. Really appreciate it.

  The guy went to the disaster relief place to get the Corp of Injunears to tarp the addition. He mentioned the "Hot" doorknobe and such, and they are sending an "electrical contractor" out.  Notice how nobody is an Electrician anymore???   : : ;D ;D :D :D

[isawlogs]

Sure hope you up-date us on that * hot * probleme . I 'm no electrishan Don't know notin about it but was very intrested on what would be the cause , I'm one of them that if there is a live wire anywhere trust me to find it   without even looking .....

[Fla._Deadheader]

  Gotta keep yer "Battery" charged, on a regular basis, isawlogs. :D :D :D