When standing outside and its raining I sometimes get shocked touching the outside of the bus. It is plugged into shore power. Is this super dangerous? Can I eliminate this by grounding the chassis to a metal rod into the ground? How far down would I have to pound it into the earth?
I just noticed that my shore cord is missing the ground pin. Is that my problem? Do I need to ground the bus when using shore power only?
YES It's dangerous and yes you need a ground pin on you plug.....
People have died from shock's like that......
Be careful and get it fixed!!!
additional info
From Issue 492 of RV Travel Newsletter 07/30/2011
Editor's corner
With Chuck Woodbury
Your RV can kill you. Not just in a traffic accident, but by merely stepping into it.
Here is the gist of an article from last Monday's Muncie Indiana Starpress newspaper:
A Muncie teen died early last Sunday after being electrocuted by his family's RV. David L. Boyle III, 18, was pronounced dead at IU Health Ball Memorial Hospital shortly after he was shocked, according to Delaware County Coroner Scott Hahn.
Hahn said a camper behind the residence became energized after an electrical wire was run from the house to the camper. "When they would go (into the camper), they would feel a little jolt, so they wrapped the door knob in electrical tape so when they turned it, they wouldn't get shocked," Hahn said.
Boyle, who Hahn said was barefoot was electrocuted as he stepped from the wet ground onto the camper's metal step. "It caused an arrhythmia in (Boyle's) heart," Hahn said.
What a terrible, unfortunate accident -- one that was so easily preventable. I asked our RV electric expert Mike Sokol to comment. He said:
"Anytime you feel a shock or even a tingle while touching the body or doorknob of an RV, it's a warning that the vehicle has a hot-skin condition. The same goes for any sort of power tool or appliance, you should NEVER feel a shock or tingle. If you do feel a tingle it means there's at least 30 volts AC on the chassis and body of the vehicle. And as little as 30 or 40 AC volts through your heart can cause it to go into fibrillation. Without intervention from emergency rescue personnel, you'll almost certainly die from electrocution."
Why this accident happened
"I would suspect that they plugged the RV into a non-grounded power outlet or extension cord with a broken-off ground pin. That allowed the body of the RV to drift up to 100 volts or so. That's why they put electrical tape on the doorknob; they were feeling an electrical tingle on the knob earlier that week which wasn't enough to cause electrocution since they were most likely wearing shoes. But they didn't realize that the entire RV body was hot-skin energized, and the boy was standing in bare feet on the wet ground while touching a hot-skin RV which completed the electrical circuit. His heart went into fibrillation, and he died from coronary arrest.
"If you ever feel of any kind of electric shock or jolt from your RV you should always unplug from shore power and examine all ground connections. NEVER accept feeling a shock from your RV. It could kill you the next time."
"Time to start checking those plug-ins at all RV camp sites.....
Do I also need to ground the chassis to the earth?
Yes fix the ground pin; however you have voltage leaking to the frame and finding a path through your body when you touch it. Not good.
Hopefully when you get the ground bond fixed it will blow the circuit breaker on the circuit that is leaking the voltage and you can narrow it to one circuit, or perhaps it was finding a current path in the wet environment and may go away after you fix the grounding conductor pin.
I guess my question actually is... Should I drive a metal rod into the ground and hook it up to the chassis? I have never done that before, is it necessary?
Yikes! This is a real bad one. The ground pin of the shore cable should be grounded to the frame of the bus, this should already have been done so once you replace the ground pin, you should be good.....but do it right now! Many electrical appliances have some intentional conductive path to ground from the 120v leads so that is the shock you are feeling, if there was a short to ground and the bus had solid 120v on the chassis, it would have knocked you on your butt, not just a tingle. Fix this quick!!!
I do not think you need any kind of ground rod, just a good ground connection to the shore power ground.
OK thanks guys!!!! On my way to home depot!
Quote from: Oregonconversion on January 11, 2013, 03:02:35 PM
I guess my question actually is... Should I drive a metal rod into the ground and hook it up to the chassis? I have never done that before, is it necessary?
no, not if you get ground fixed....
Plus check your hookup, power source to be sure it's correct.......... and the power cord it's self....
if it's not the same you can and will have problems.....
If you cannot or feel you don't have the expertise then by all means find someone that does.......
better safe than sorry
Hate to say use search function but in this case is complicated. Lots of factors;30 amp plug-50 amp earth ground bonds,power transfer switch, and more. You should never get shocked! If not ask more. How many wire in your cord? What colors? Green should be earth ground. white neutral . black and red hot.for 50 amp. We never know what someone may have switched. Bob
I would not trust that cable ... period. Go get a new cable that matches your coach electrical connection, or at the very least a new connector. West Marine is but one place on line that carries replacement sockets.
Oh yeah, if you don't have basic electrical skills, call on someone that does. The wife won't let me do anymore household electrical jobs since I sparked a live wire off some BX cable several years ago. I had the cable held between my knees while relocating a wall switch. The wife was concerned for the family, well, jewels!
Speaking of that, take off any jewelry before beginning work on anything electrical. My uncle got a ring caught between a battery post and the fender well of a car, result was a second degree burn around the finger. Only 12 volts but several hundred amps and a direct connection to ground.
Oh, and no you don't solve the problem by driving a ground rod. In fact, depending on your soil conditions an 8' copper ground rod can be totally ineffective at establishing a good ground. In sandy soil you may need to go multiple 8' lengths deep or drive a pattern of 8' rods tied together to get a satisfactory ground connection.
Will
In my opinion you have at least two problems that need to be fixed. The missing ground pin needs to be addressed immediately, which it sounds like you are doing. The second thing is to determine where you have an electrical path to the bus skin. One possible cause is that the outlet that your shore cord is plugged into is mis-wired. Check that. Another is that neutral and ground are connected together in the bus electrical panel. There should be an insulated neutral bar that only has white wires on it, and a ground bar attached directly to the panel that has only green or bare wires connected to it . Another less likely possibility is that there is an appliance problem. Turn off all breakers in the bus panel to see if the problem goes away. If it does, turn on one breaker at a time until you find the problem. As has been said, if you don't feel qualified to diagnose the problem, find someone who is. Above all work safely. DO NOT touch the bus skin with the shore cord plugged in until you find and fix the problems.
Good luck, Sam
I know what I would do - fix the ground path and put a ground stake in the ground for the bus chassis instantly, only because I've been there and done that, but I don't know the real answer about independently grounding the bus chassis. I think it's always OK, but I have some doubt... People go on about how you need a 8 foot copper bus bar driven into the ground, but I have fixed this with a big screwdriver stuck in the ground and a 4 gauge battery boost cable. Maybe the Sailor Sean will drop in...
Brian
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,
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.
I put a new plug on the cord and that fixed the problem, no more shocks. :) 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 ::)
Quote from: Oregonconversion on January 12, 2013, 04:47:54 AM
I put a new plug on the cord and that fixed the problem, no more shocks. :) 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 ::)
Congrats......... Better now than never...... :D
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
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
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
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!
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.
Bruce, how much is the permissible voltage leak for a 120v appliance?
Note: should have said 120v, so it has been corrected.
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.
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......
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
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
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.
Sent from my iPhone using Tapatalk
There should be NO leakage with the possible exception of capacitors as mentioned. You should be able to measure with an ohmmeter between the neutral and ground on the main plug and get infinity. Between hot and ground you may see a small kick in the meter (analog) as the capacitors charge up but it should also rise to infinity. Only between hot and neutral should you get a resistance reading at all, that is measuring across the various loads that may be connected.
I prefer an older analog meter for these tests but a digital will work.
Your problem could be totally unrelated to your electrical system, other than needing to have the ground pin connected.
Try to follow this: every Labor Day I set up a food trailer in the park for the American Legion. We have about a 30 amp supply directly out of the distribution box. The trailer was wired by me, so I know it is all correct. (no attitude with that statement). As other vendors started hooking into local outlets for coffee and hot dog machines, one of our members touched the trailer and got a shock. (he's ok) I went through everything I could possibly think of and then ran an idea by the local electrician. As more people were connecting in, the voltage would shift on one leg to 140 volts and the other leg would go to about 70 or 80. We also tried adding a ground rod and it do not help. My suspicion was correct, the neutral to the main distribution box was weak and our electrical system was completing the circuit to everybody elses equipment via the ground. We ran a temporary neutral for the weekend and all was well.
On another occaision, I had a co-worker phone me that her son was getting shocked standing in the garage touching the rail for the overhead door. He was in bare feet. I determined that the garage neutral was bad and needed to be replaced. It was at this time in my life that I also discovered that CONCRETE IS CONDUCTIVE. I was able to touch one lead of my meter to the rail and the other to the concrete and I read over 90 volts.
When you first set up camp, take a meter with you and stick one end in the ground and the other end on the frame of your bus. Look for voltage. If any is present, disconnect your shore line before it kills you!!!
Happy hunting.
Ed
Quote from: pvcces 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.
I'm Mike Sokol, the writer of the Church Woodbury article quoted at the top of this thread, and author of the www.NoShockZone.org (http://www.noshockzone.org) website about RV electrical safety. I'm getting ready to write some new articles about RV hot skin conditions, and researching misconceptions about how they occur. So much more on this later, but here's the basics.
1) For a hot-skin condition to occur you first need an open or high resistance safety ground connection between the chassis/skin of your RV and the Ground-Neutral-Earth bonding point back at the main electrical service panel. Most of the time it's caused by an open ground wire connection inside a dog-bone or pig-tail adapter, but can also occur from a worn or damaged pedestal outlet, mis-wired home receptacle, or even a broken or non-existent wire in a power feed. I've found RV's with loose grounding screws in their own circuit breaker panel, and at least one of them with a broken ground lug on the back of the shore power twist-lock connector. This safety ground needs to have a very low impedance path all the way back to the entrance service panel (less than 1 ohm total) to meet electrical code standards. And no, a ground rod driven into the earth next to your RV will do little or nothing to actually "ground" your RV since a ground rod can have up to 100 ohms impedance to earth and still be code compliant. The ground rod's job is actually to drain away lightning strike currents and keep the local grid's ground voltage close to earth potential.
2) You need a source of leakage current to electrify the skin of the RV. Now I want to correct the statement made in the quote above. Virtually ALL electrical appliances plugged into a 120-volt outlet will have leakage currents to their own chassis. And that amount of current is regulated by UL and the NEC. An appliance without a grounded plug is limited to a maximum leakage current of 0.75 mA (milli-amperes). You'll find that "ungrounded" appliances such as a crock-pot, iPhone charger, or laptop computer will normally develop a "hot-skin" potential around 60 volts even when everything is operating correctly. But because the current is limited by UL standards to less to 0.75 mA, you'll never feel a shock. Just over 1 mA of 120-volts, 60 Hz AC is the lower threshold of feeling a shock, which is certainly not dangerous. However, appliances with a grounded plug can have a maximum of 3.5 mA of leakage current between the line and chassis and still be within UL guidelines. Normally that 3.5 mA of leakage current is drained away harmlessly by the safety ground path of your RV. But if your RV's safety ground path is compromised, then there's nothing to drain away that leakage current and a hot-skin voltage is the result.
3) Those hot-skin voltages come in two flavors, high-current and low-current. The low-current hot-skin condition can be caused by a single appliance inside your RV with normal leakage currents. This can be a microwave oven, RV battery inverter, refrigerator, television set, or even a computer with a grounded power cord plugged into your RV's 120-volt system. Also note that these appliance leakage currents are additive, so 2 or 3 mA of leakage from your microwave can add to the 2 or 3 mA of leakage from a MOV surge strip (yes, they leak current to the safety ground as well). So it's entirely possible to generate over 5 mA of leakage current to ground which will trip a GFCI 20-amp receptacle on your campsite pedestal.
4) A high-current hot-skin condition is typically caused by a wire inside the walls of your RV being drilled through by a screw, or pinched by a box cover, or even worn through insulation that's hanging on a metal crossbeam. High-current hot skins can easily provide dozens of amps of current, so if you touch an RV with a high-current hot-skin, your body's 1,000 ohm resistance (damp hand to hand or hand to foot) can cause up to 120 mA of shock current to flow through your chest cavity. Note that only 10 mA of 60 Hz current is dangerous to a person with a weak heart and is very painful, 20 mA will cause your muscles to seize to the point where you can't let go of an electrified object, and 30 mA of current through your chest cavity for a few seconds is nearly always fatal without immediate CPR and defibrillation.
So, it's completely possible to trip a GFCI at a 20-amp pedestal outlet and to have nothing specifically wrong with an RV electrical system. It's also possible to generate a 120-volt hot-skin condition from a broken safety ground wire that results from these same high-impedance leakage currents from several of your RV appliances, all of which are operating within UL leakage limits.
A ground rod driven next to your RV can drain away a high-impedance (low-current) hot-skin voltage, but will do NOTHING to stop a low-impedance (high current) hot-skin voltage. And putting your leveling jacks down on the dirt will do nothing to "ground" your RV, contrary to popular belief. And as little as 30-volts AC across wet hands can induce 30 mA of current across your heart and be deadly.
The takeaway is that your should NEVER feel any type of shock from any appliance or RV. If you do feel a shock, then shut it down and unplug immediately and get it checked by a licensed electrician or technician. However, note that there's a lot of electricians and technicians who don't seem to understand what causes shock conditions, so if there's any doubt, measure the hot-skin voltage yourself. Here's an article I wrote on how to test for hot-skin voltages using a simple Non Contact Voltage Tester (NCVT) which you can purchase online or at any big-box store for less than $25 (and many times less than $15). See http://www.noshockzone.org/rv-electrical-safety-part-iv- (http://www.noshockzone.org/rv-electrical-safety-part-iv-)–-hot-skin/ for the article.
Please let me know if that makes sense and contact me at mike@noshockzone.org with any questions.
Mike Sokol
www.NoShockZone.org (http://www.noshockzone.org)
mike@noshockzone.org
I had this problem and in my case it was caused by the neutral and ground being connected in the breaker panel in the bus.
Quote from: Bob & Tracey on November 08, 2013, 06:25:33 AM
I had this problem and in my case it was caused by the neutral and ground being connected in the breaker panel in the bus.
Connecting the neutral and ground wires together in your RV breaker panel is a violation of both NEC and RVIA wiring code. They MUST remain separated, only to be bonded together at the incoming electrical service panel, or by your portable or on-board generator. The same goes for subpanels at a campground (the pedestals). There can be no bond between the neutral and ground wires in the pedestal, and code doesn't allow a local ground rod to take the place of a low-impedance (less than 1 ohm) safety ground wire that's run back to the incoming service panel. The NEC does not "disallow" having additional "local" ground rods, but without a connection back to the service panel they can't protect you from a low-impedance (high current) ground fault. The ground-rod confusion comes from the fact that a local ground-rod can drain away high-impedance (low current) shock voltage caused by normal RV appliance leakage (as I've detailed above), but will do nothing to protect you from a high-current hot-skin condition.
Mike Sokol
www.NoShockZone.org (http://www.noshockzone.org)
Mike,
Don't yell at me, I didn't do it. ;D
Quote from: Bob & Tracey on November 08, 2013, 12:10:24 PM
Mike,
Don't yell at me, I didn't do it. ;D
I'm not yelling (yet). ::)
I can see a problem with bus conversions is that many hands have been in the stewpot before you ever got into the kitchen. So dangerous miswiring conditions could be in place years before you acquire a bus or convert one. I'll do what I can to help keep you guys safe from electrical dangers.
Mike Sokol
www.NoShockZone.org (http://www.noshockzone.org)
JMSOKOL- Welcome to the board - we have somewhat lost Sean Welsh due to his transfer to a trawler (boat) - hopefully you will be able to take over where he left off - check the archives to see what I'm referencing - Are you sure you're not Sean using a pseudonym ???
Quote from: niles500 on November 08, 2013, 11:34:46 PM
JMSOKOL- Welcome to the board - we have somewhat lost Sean Welsh due to his transfer to a trawler (boat) - hopefully you will be able to take over where he left off - check the archives to see what I'm referencing - Are you sure you're not Sean using a pseudonym ???
Hmmmm..... Not sure who this Sean Welsh guy is, but I assume from his postings that he's an electrical guru of sorts. But no, I'm not Sean working for the CIA in disguise (but even if I were, I couldn't tell you). I'm just a Mechanical/Electrical/Audio engineer and received my Master Electrician License in 1978.
However, I'm not a bus guy, or even a camping guy. I did in fact camp across 40 states and half of Canada back in the 60's and 70's with my parents. But now I'm a nationwide seminar instructor who drives 50,000 miles a year teaching music mixing and sound production. But I've been interested in electrical safety since the 70's, and got really interested in tour bus electrical safety when some of my pro-sound buddies doing major music tours complained about getting shocked. Now, a tour bus for a rock star is essentially what you guys have, just on a more modest budget. But the same electrical shock hazards exist for ANY type of RV plugged into a shore power connection.
That's why I started www.NoShockZone.org (http://www.noshockzone.org). I found a lot of confusion about RV wiring and electrical shock hazards, even from some of the so-called "experts". In fact, I've pioneered the use of NCVT (Non Contact Voltage Testers) for finding RV Hot-Skin conditions. See below for a video where I hot-skin electrify a 40-ft RV and test for the condition with a Fluke VoltAlert NCVT.
I've also discovered and named an outlet miswiring condition that much of the electrical industry seems to misunderstand or ignore. Check out my article at EC&M magazine and The RV Doctor's site about something I call an RPBG (Reverse Polarity Bootleg Ground) mis-wiring condition that will create a hot-skin condition on ANY RV or Bus plugged into it, and there's no surge protector or voltage monitor on the market that will warn you or disconnect you from it. http://www.rvdoctor.com/2001/07/friends-of-gary-mike.html (http://www.rvdoctor.com/2001/07/friends-of-gary-mike.html) and http://ecmweb.com/contractor/failures-outlet-testing-exposed (http://ecmweb.com/contractor/failures-outlet-testing-exposed) However, a $20 NCVT will easily find an RPBG mis-wired outlet and identify a hot-skin condition on your bus that results from plugging your shore power line into one. I'm now trying to identify just how my RPBG mis-wired outlets exist in the country, but it's certainly something to watch out for when plugging into "garage outlet" power while visiting someone in their driveway.
So while I'm not a "Bus-Nut" or even a camping guy, I'm totally into bus wiring and electrical safety for consumers. Please give me a shout-out if you see any threads on this forum that could use my help. My direct email is mike@noshockzone.org
Mike Sokol
www.NoShockZone.org (http://www.noshockzone.org)
(http://www.youtube.com/watch?v=Y8h64X33aKg#)
Mike,
Welcome to the board and thanks so much for taking the time to share good information. Watch out though. If you hang around these parts long enough you might get a touch of busitetis.
-Sean
www.herdofturtles.org (http://www.herdofturtles.org)
1984 Eagle Model 10S
Quote from: Seangie on November 09, 2013, 02:29:17 PM
If you hang around these parts long enough you might get a touch of busitetis.
I admit to having looked at busses in a lustful way. Is that the first symptom?
Mike
That's how it starts, Mike! ;) ;D
Quote from: Stormcloud on November 09, 2013, 07:40:02 PMThat's how it starts, Mike! ;) ;D
Yeah, if you ever catch yourself saying "That looks good!", "I can do better than that", "it won't take long", and "that won't cost much" within a 30 minute period, have someone lock you in a small room and throw away the key!!!
Thank you for sharing your expertise. A lot of us guys need it.
Constructive info/help is always the goal here!! Death trap--I wouldn't step foot in that thing type statements don't help a person correct a problem or do it correct when _I_ or someone else makes a mistake. I have just disassembled a pro conversion because of a fire that I would consider sub standard. Everyone here goal is to do the best with the most correct info available. That is why I only share mostly my mistakes!! Take this for what it is worth. Lots of variables here that are not in sticks and staples that the over the hill gang has been there and done that wrong.... Will be asking questions because I'm electric challenged but just remember keep them simple I don't have the diploma you do. Bob
After contacting him pertaining to the correct Fluke model non contact pen, I ordered one online. Reasonably priced for the benefit. Thanks for the eye opening info, and welcome to the Bus Conversion psycho site!! This video of his outlines the correct one to purchase:
How-To RV Hot-Skin Testing: Q&A (http://www.youtube.com/watch?v=obeh9m4OMv4#)
Quote from: chessie4905 on November 10, 2013, 06:03:46 AM
After contacting him pertaining to the correct Fluke model non contact pen, I ordered one online.
These Non Contact Voltage Testers (NCVTs) are also great for checking outlet polarity as well as looking for RV hot-skin voltage. My favorite is the Fluke VoltAlert, but I also have samples from Amprobe, Klein, Extech and others that work just as well. What you're looking for is one rated for 90 to 1,000 or 60 to 600 volts. Testers with that sensitivity will be able to tell the difference between the hot and neutral sides of a standard 120-volt receptacle, and find a large hot-skin surface down to 40 volts AC or so. Of course, the gold standard is to use a digital meter between a ground rod and the outlet or RV chassis/skin. But that's a test usually only performed for serious troubleshooting or after somebody dies. I believe that the NCVT proximity test is a simple and safe hot-skin and polarity test that anyone should perform every time they plug into an unknown shore power receptacle.
See below for a video on how to use a NCVT to check outlet polarity
Mike Sokol
www.NoShockZone.org (http://www.noshockzone.org)
(http://www.youtube.com/watch?v=jF3Ntoa8ab8#)
I can never figger out how them little electrictrons run around in things so all this info (with pitchurs - pitchurs are good; I went to a night school so I don't read so good in the day time) is much appreciated! Many thanks, Mike
BH NC USA
Quote from: Oonrahnjay on November 10, 2013, 03:08:32 PM
I can never figger out how them little electrons run around in things...
I taught myself about electricity beginning when I was 12 years old and by the time I turned 16 I was building all sorts of sound and music gear for my bands. I actually think about electrons as running around in pipes and tanks, much like water in a hose. So if you can understand basic plumbing, I can teach you electricity and electronics.
Of course, there's lots of special devices in electronics, so it gets complicated pretty quickly. But just like in your bus, if you can break the most complicated machine down into the many smaller machines it's made of, just about everything is understandable and repairable.
Mike Sokol
www.NoShockZone.org (http://www.noshockzone.org)
Don't assume that your plug is actually wired right. We have recently installed a 50amp reel. It had worked fine at home. Worked fine everywhere in California. We stopped for one night on our last trip and our inverter faulted out. We thought there might be a problem with the pedestal, but we were only there for the night so we disconnected. Stopped for three nights at an RV park and all was well. The next park, it faulted again. "Lost neutral" We got to thinking that maybe there was a short in the plug and took it apart. The ground and neutral wires were reversed. It worked if the neutral and ground had been bonded in the panel box, but not if they were left separate.
Don and Cary
This statement is confusing....very confusing.
It worked if the neutral and ground had been bonded in the panel box, but not if they were left separate.
Which makes this one even more confusing...
We got to thinking that maybe there was a short in the plug and took it apart. The ground and neutral wires were reversed.....
if this is true, why did it work at all ?
Quote from: robertglines1 on January 14, 2013, 08:01:20 AM
I have made grounding mistakes in past for sure because I did not understand! The new coach build --is much better.
Not to worry, Bob -- every ounce of house wire was stripped out of your old chassis, and new wiring installed by a licensed electrician. The thing is just about un-finishable, but at least the electrical system is safe! Haven't touched the project in six or eight months now...
Cheers, John
Quote from: eagle19952 on November 10, 2013, 05:25:57 PM
This statement is confusing....very confusing.
It worked if the neutral and ground had been bonded in the panel box, but not if they were left separate.
Which makes this one even more confusing...
We got to thinking that maybe there was a short in the plug and took it apart. The ground and neutral wires were reversed.....
if this is true, why did it work at all ?
I've seen a number of outlets with the ground and neutral reversed, and while they seemed to work most of the time, there were some pretty strange artifacts introduced. That's because the neutral wire will always have an out of phase voltage drop when compared to the hot wire voltage drop. So if your 120-volts is dropping to 110-volt due to a lot of current draw, half of the drop (5 volts) will be on the hot wire, and the other half of the drop (5 volts) will be on the neutral wire. But while the neutral wire's potential jumps up and down with load, the safety ground wire is never supposed to have any current draw (except in a fault condition) and thus will have no voltage drop. So the safety ground wire should maintain a voltage potential very close to earth voltage. If the ground and neutral wires are reversed, then your voltage protector will see the voltage drop in the wrong wire and assume the neutral or ground wire has opened up.
If you short the ground and neutral wires together in the panel, you're essentially using the ground wire as an extra neutral wire, and their voltage drops will match each other. Since many voltage protectors measure the voltage between the neutral and ground wire (looking for an open neutral in a 240-volt / 50-amp receptacle) then you've bypassed its ability to see an open neutral and protect you from it. Shorting (bonding) the neutral and ground together in a sub-panel is a violation of code and never a good idea.
Mike Sokol
Quote from: jmsokol on November 10, 2013, 11:39:21 AM
... Of course, the gold standard is to use a digital meter between a ground rod and the outlet or RV chassis/skin. But that's a test usually only performed for serious troubleshooting or after somebody dies. I believe that the NCVT proximity test is a simple and safe hot-skin and polarity test that anyone should perform every time they plug into an unknown shore power receptacle.
Do you have a video that details the procedure for using a digital meter to test the skin?
Quote from: gumpy on November 10, 2013, 07:48:54 PMDo you have a video that details the procedure for using a digital meter to test the skin?
Hey, Gumpy. There are two videos posted right at the top of this page of this topic (at least, it's the same page of my browser). Do they cover what you were asking for? Best wishes, BH
Quote from: Oonrahnjay on November 11, 2013, 04:00:19 AM
Hey, Gumpy. There are two videos posted right at the top of this page of this topic (at least, it's the same page of my browser). Do they cover what you were asking for? Best wishes, BH
Here's an article I wrote about how to use a digital voltmeter or Non Contact Voltage Tester to check for an RV hot-skin condition.
http://www.noshockzone.org/rv-electrical-safety-part-iv-%E2%80%93-hot-skin/ (http://www.noshockzone.org/rv-electrical-safety-part-iv-%E2%80%93-hot-skin/)
Mike Sokol
www.NoShockZone.rg (http://www.noshockzone.rg)
As a side note, I'm fishing around for a grant that would allow me to expand NoShockZone.org into a road tour which would visit campgrounds and RV rallies around the country. All my demonstrations are portable and I could easily present a 90 minute seminar on measuring campground voltages and checking for RV hot-skin conditions. Or I could expand it to become an electricity theory and troubleshooting class with separate AC-DC modules over a several day span.
It's been slow going so far since the test gear manufacturers don't seem to recognize the huge numbers of people in the USA who actually have an RV of some sort. My info from RVIA indicate that 1 out of every 11 families in the US has an RV of some sort. That's a lot of RVs.
If anyone has an idea on where to look for funding, please email me at mike@noshockzone.org with suggestions.
Mike Sokol
mike@noshockzone.org
www.noshockzone.org (http://www.noshockzone.org)
Quote from: jmsokol on November 11, 2013, 05:59:18 AM
As a side note, I'm fishing around for a grant that would allow me to expand NoShockZone.org into a road tour which would visit campgrounds and RV rallies around the country.
Mike -If you can, you might try to make it down to Arcadia, FL for the big bus/rv rally that's taking place over New Year's. Bill & Brenda do a good job following the footsteps of Jack & Paula who got this thing rolling. 13th or 14th year now, and they always have tech sessions. Yours would fit right in.
Visit www.arcadiarally.com (http://www.arcadiarally.com) for details and contact info.
I have some other ideas for you, send me a private message.
FWIW & HTH. . .
;)
Just a heads-up. I recently expanded one of my answers on this thread into a full article for RV Education 101 Magazine where I discuss both low-current and high-current hot skin conditions and what causes each of them.
See http://www.rvuniversity.com/article.php/2013113015512298 (http://www.rvuniversity.com/article.php/2013113015512298) for that issue.
Keep up the good work on spreading the word about electrical safety for your bus conversions. And NEVER accept getting a shock from any vehicle or appliance as normal. It's not safe and needs to be corrected immediately.
Mike Sokol
mike@noshockzone.org
www.noshockzone.org (http://www.noshockzone.org)