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Author Topic: HALP! Getting electrical shocked from bus 110V electricity shocking shock  (Read 6450 times)
akroyaleagle
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« Reply #15 on: January 11, 2013, 07:03:29 PM »

I am not an electrician!

I have seen this problem before. It may be the power pedestal. In older parks that may be the problem.

More often than not I have found neutral and ground were getting together in the power cord end. Unplug, open up the end of your power cord and make sure all the wire connections are clean and tight. This seems to happen when others are helping you unhook and pull the cord out by the cord and not the plug. If the short is intermittent, this is probably the cause.

If one of these is not the problem, it could be any of the things previously mentioned.

I don't believe a ground stake would be beneficial. You might just as well throw a chain over the hitch, it would probably work better.

Good Luck,
« Last Edit: January 11, 2013, 07:05:49 PM by akroyaleagle » Logged

Joe Laird
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Ed Hackenbruch
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« Reply #16 on: January 11, 2013, 07:38:04 PM »

Back when we first started fulltiming we stopped at a friend's place in Montana to visit for a few days. He had set up a power pedestal for us in his back yard. The first nite there it rained a little bit, the next  morning the dog went out the door ahead of me and as his front feet hit the ground he yelped and jumped away from the bus. As i stepped out i found out why he yelped when i got shocked. Turned out that the guy had wired it wrong, should have tested it BEFORE i plugged in,.......which is what i now do every time i hookup to power.  Two or three times since then i have found pedestals that had problems. 
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Oregonconversion
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« Reply #17 on: January 12, 2013, 04:47:54 AM »

I put a new plug on the cord and that fixed the problem, no more shocks.  Smiley Everything is wired correct from the inverter to the breaker.... 0000 gauge copper for ground to chassis!!

Could have been a good anti theft device though  Roll Eyes

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« Reply #18 on: January 12, 2013, 05:57:55 AM »

I put a new plug on the cord and that fixed the problem, no more shocks.  Smiley Everything is wired correct from the inverter to the breaker.... 0000 gauge copper for ground to chassis!!

Could have been a good anti theft device though  Roll Eyes



Congrats......... Better now than never...... Cheesy
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« Reply #19 on: January 12, 2013, 10:10:17 AM »

I'd be suspicious that this coach will trip a ground fault protection device.

There is still the problem of how there is power being introduced to the coach body.

Replacing the broken ground plug only hides this problem again.

Get some help and track it down!

happy coaching!
buswarrior

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bevans6
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« Reply #20 on: January 12, 2013, 10:24:48 AM »

Voltage can be transferred to the coach body without any physical connection, through induction.  What you get is a trace or phantom voltage induced into the coach chassis if the chassis is not grounded properly, to actual ground (the planet earth, terra firma).  This can even be a result of parking near a high voltage power line.  The voltage is usually in the 40 - 90 volt range, is AC, and has virtually no current capacity, hence is very easy to disperse with even a rudimentary ground connection.  That's why I've personally fixed it with a ground via a screwdriver into damp earth.  In fact I was able to measure the phantom voltage by sticking one meter lead into the damp earth beside the bus.  Not having any ground at all, as in the case of a missing ground terminal on a cord or outlet is a real opportunity for this kind of voltage to be induced, and even a corroded or high resistance connection to ground will do it.  As another example, a coiled up power cord lain on the metal luggage bay floor can easily induce current into the bus - you've basically created a really basic transformer.  

Edit - this is not to say that a faulty connector isn't the most likely cause of a hot chassis condition, just that it's not the only way to get some measurable voltage on the chassis.

Brian
« Last Edit: January 12, 2013, 10:33:58 AM by bevans6 » Logged

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« Reply #21 on: January 12, 2013, 11:02:32 AM »

Had the same problem. I do not remember what my RV gen guy did but I do know he put in a new panel and said something about on a RV you have to ground it to the ground bar. Not much help but I think you do need a qualified electriction to fix this right. No need to fry yourself or others, it will be cheap compared to a funeral or hospital. I do a lot of things myself but things like electric I get some one who knows the stuff.
ED
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« Reply #22 on: January 12, 2013, 12:43:38 PM »

No, you should not need a ground stake for the bus.  However, I have considered grounding the bus with a metal tent stake when plugged in at campgrounds just in case they have, or develop a problem while I am plugged in.  In your case, I would probably be curious enough to put some metal into the ground and use a multimeter to see what king of voltage is passing.  Yes, as mentioned you must fix the damaged plug, check it for other damage, check it's connections and receptacle, and then go on from their.  Inspection the connections in the panel is a good idea as is also trying to isolate the various circuits (turning breakers on and off) to see if any of them are responsible.  It may take a while, but even if it does it will not be heavy lifting, and you will gain more knowledge of your layout.

I not have to do something similar since there is a smell of propane in my bus.  Of course, I can easily find the problem with a torch!
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« Reply #23 on: January 12, 2013, 02:03:32 PM »

Guys

As I said in my previous post, when we are dealing with 120v appliances and electronic equipment, it is very common to have components in these devices connected between the 120 v hot lead and ground. This makes a small amount of ground current,(it is limited by safety standards). When you lose the ground to the bus as happend with this damaged cord plug, you will get a shock from the bus body, as you are completing the ground path.  This small current is normal and does not mean anything is wrong. If you have many devices on the bus, this current will increase a bit for each one and can give you quite a shock if not properly grounded. If there was a short, breakers would be popping when the ground pin was fixed.

As always, when we are talking about electrical safety, it is best to get it checked out if there is any question but my bet is that this was just normal ground leakage current and fixing the missing ground pin should be the end of it.
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Bruce & Nancy Fagley
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« Reply #24 on: January 12, 2013, 03:37:04 PM »

Bruce, how much is the permissible voltage leak for a 120v appliance?

Note: should have said 120v, so it has been corrected.
« Last Edit: January 12, 2013, 07:11:35 PM by Lin » Logged

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« Reply #25 on: January 12, 2013, 03:56:00 PM »

  What I suspect is the problem is that one or more of the 120v outlets in the bus is wired wrong-- all outlets should have the ground, hot and neutral going  back to the bus electrical box , and that ground should go back to the generator.  The bus ground should be able to be transfered from the generator to the shore power cord just like the hots and the neutral. 

I bet someone hooked up a neutral wire directly to the bus chassis.
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Geoff
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« Reply #26 on: January 12, 2013, 05:17:19 PM »

Lin

12v appliances or devices don't have this problem. This is an issues with devices that operate at 120v. These products are allowed a few milliamperes of current to ground.....so if there are many connected to 120v.......microwave, TV, battery chargers...etc, the current adds up and can certainly give you a shock if the ground is removed.

I am not an expert on bus electrical systems by any means, so there could be something bus specific going on here that I know nothing about......
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Bruce & Nancy Fagley
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« Reply #27 on: January 13, 2013, 11:01:26 PM »

For what it's worth, there is no approved continuous leakage to ground in AC appliances. Televisions and inverters sometimes have small value condensers connected to ground that will pass a tiny current. GFCIs are designed to trip if there is an unbalance in the current in the black and white leads. This is so that they will trip even if the current is running to earth.

GFCI outlets that I have tested will trip on about five milliamps of current difference, about half of what it takes to kill someone healthy if the current runs through the body. They are pretty fast, and I have had one save me from a nasty shock.

Grounds are supposed to be all connected at all times; it's the neutral that has to be switched from power source to power source.

Also, anytime power is run to a sub box or panel, no additional ground rod is required or permitted. The main panel is the proper place for an RV's ground. In a campground, that may be quite a distance away. I don't think the power pedestal can provide the earth ground because there would then be multiple connections to earth ground.

YMMV. Be careful!

Tom Caffrey
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Tom Caffrey PD4106-2576
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robertglines1
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« Reply #28 on: January 14, 2013, 08:01:20 AM »

Will add one old school trick when all is perfect :: I still have habit of touching unknown door of camper/coach with back of finger first! Why? your finger will contract closed away from the door instead of making it contract firmly against the door making a better contact for a longer period.   Just trivia and a old habit.  I have made grounding mistakes in past for sure because I did not understand! The new coach build --is much better.  There are testers you can buy at Lowes that plug into your receptables that tell you if it is wired correct. Had a wire break on a factory shoreplug (common  white) and cost me a air conditioner and several appliances.   Again FWIW    Bob
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« Reply #29 on: January 14, 2013, 10:29:47 AM »

Well said, Bob.
The old backhand trick, after all other voltmeter tests, is a much better final test than grabbing something hot and dying there for not being able to let go.
Ted.


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