Shocking 2015 ACE 30.2

[captainjohn413]

Hi, I just washed our ACE to put it away for the winter. Has anyone else had to deal with an electrical shocking problem when plugged into to shore power?

John

[FW28z]

Does that mean you got shocked, or are you just concerned about such a problem?

[captainjohn413]

Yes, I did get shocked. I could not even bare handed touch the door handle to access the coach. The dealer is looking into itm and I will post as soon as they find anything.

[fhenn]

It is either a bad ground in the coach or in the external hook up (Generally)

[FW28z]

Firstly I would ascertain that the power you are plugged into is wired right. If you did not notice the problem until now (unless you just bought it).

You can buy an inexpensive meter; such as the Prime Products 12-4058 that shows the voltage plus whether or not the ground is bad and whether or not the neutral and hot wires are reversed. Plug it into the power pedestal using a 50/30/20 amp if needed rather than plugging it into the coach (of course, you can check each outlet in your coach too).

Regardless of any resolution to your immediate problem, such a meter is highly recommended as you may want to check power at each campsite you visit.

[captainjohn413]

I tested the cord, and circuit that I was using to power the coaches shore power. I ran that circuit a few years back, testing it everything shows good. I tried to ring out the coaches circuit using an ohm meter, but all looks good. Just a little explanation, yes we did just buy the ACE. I really do appreciate all help, and suggestions. Thank you. The ACE is so nice, and we want everything the way it should be.

[mbutts4901]

Here's an article on RV Hot Skin issues:

RV Electrical Safety: Part IV – Hot Skin | No~Shock~Zone

[FW28z]

What you want to do is measure your power inlet to ensure it is wired correctly. When you measure from neutral to ground, there should be no voltage. If you see voltage then the wiring is reversed (hot and neutral connections reversed).



If the power pedestal checks out OK, check the motorhome itself for reversed wiring in one of the circuits (or the main breaker).

In motorhomes, in my view, there is a huge problem with wiring... at least when compared to boats. In boats, both the hot and neutral wires have a main breaker, and the ground wire is NOT connected to the neutral wire like it typically is in a residential situation.

This is a safety thing.

However, when you connect the boat to the shorepower pedestal, the neutral and ground are tied together at the pedestal, so by proxy, the neutral and ground are tied together at the boat as well as soon as it is connected to the shorepower outlet.

This is done to prevent safety issues due to improperly wired shorepower pedestals.

However, since RVs are cheaply made, my RV does not have a neutral breaker, and I have not yet looked to see if neutral and ground are tied together. Hopefully it is not, as it would be extremely dangerous if they were and you hooked up to a mis-wired shorepower pedestal.

If it were and you connected to a mis-wired pedestal, a neutral/ground connection (if it were connected at the RV) would result in a direct short across the 120VAC supply.

So while I have not confirmed it, there should never be a neutral/ground connection at the RV, as it should also by proxy pick up that connection via the shorepower pedestal when connected to it.

At any rate, not having a breaker on the neutral connection could result in a condition whereby the breaker is not in the circuit if the shorepower pedestal is miswired.

For that reason, I always recommend checking the shorepower pedestal with a meter that shows normal/reverse wiring prior to connecting your RV to it.

One study I read when I was into boats is that especially in certain areas of the country, it is quite common to have shorepower pedestal wiring problems. But you could always encounter any RV park with a reverse wired pedestal.

Again though, why is it that these things are done in boats, but RVs are so cheaply made that it is not part of the design? I mean, even the RV power distribution manufacturers have no clue.

Unless of course my main breaker is a two pole (both hot and neutral) and I am just not seeing it. Perhaps I should remove the front panel of my power panel and find out for sure before undue criticism (the main breaker does look to me like a standard residential single pole though).

[FW28z]

This might illustrate it better:

[FW28z]

Well the good news is that the neutral and ground are indeed separated in the RV (note the "Not Grounded" note on the drawing). So the power distribution panel manufacturer is at least up on that.

However, it sure looks to me like there is only one main breaker for the hot side, which again, can present a serous safety issue should you encounter a mis-wired shorepower pedestal.

[FW28z]

This is not good... shame on the RV industry. At a cost of a few dollars for skimping on a breaker on the main-neutral side, they are potentially putting our safety at risk.

Unless of course, I am missing something...

At minimum, I might look into getting a 120VAC buzzer and connecting it to the neutral and ground connection inside the power distribution unit. That way, if it goes off, I will immediately know that there is a mis-wired shorepower pedestal.

Really though - to be safe, I should install a twin 30A breaker for the main and breaker both the hot and neutral lines.

[jmsokol]

Originally Posted by FW28z

This is not good... shame on the RV industry. At a cost of a few dollars for skimping on a breaker on the main-neutral side, they are potentially putting our safety at risk.

I'm Mike Sokol, author of the No~Shock~Zone article lined to above. Thanks for posting it here. Actually, there are no switches or circuit breakers allowed in neutral circuits according to the National Electrical Code. And since the RVIA follows NEC guidelines, then RVs don't have switched neutrals either. Actually, there's a lot of good safety reasons for that, including keeping the neutral and ground separated inside your RV (or boat). It only gets bonded together at the generator transfer switch, or by plugging into a campground pedestal which gets its G-N bond from the main service panel. At least, that's supposed to be how it works.

If you feel ANY kind of shock, then you must have an open EGC (Equipment Grounding Conductor) more commonly called a safety ground. This mostly happens in an inexpensive dog-bone adapter, cheap extension cord, or even a mis-wired pedestal or home power outlet. Also, be aware that 3-light testers and even H-N, H-G, N-G tests won't detect some outlet mis-wired condition I call an RPBG (Reverse Polarity Bootleg Ground). See my article on the subject at The RV Doctor: Friends of Gary - Mike and Failures in Outlet Testing Exposed | Contractor content from Electrical Construction & Maintenance (EC&M) Magazine

The best and safest way to find an RV hot-skin voltage is by using a NCVT (Non Contact Voltage Tester) such as a Fluke VoltAlert or Klein NCVT-1. Here's a video of me testing a 40-ft RV for a hot-skin voltage using a NCVT.

https://www.youtube.com/watch?v=Y8h64X33aKg

and here's video I recently did on how to test a campground pedestal for correct voltage, polarity and grounding.

https://www.youtube.com/watch?v=W5pLlZm8O84

Please let me know if you have additional questions about RV electrical hookups and safety.

Mike Sokol
mike@noshockzone.org

[FW28z]

I am going to have to disagree here.

I have an older copy of the NEC, so forgive me if my information is not up to date.

In the RV section (551-11) of my older copy of the NEC, which by the way only consists of a few pages, there is only a mention that RVs shall have a distribution panel board with circuit breaker or fuse protection with an insulated (not grounded) neutral. It does not state anything about a prohibition of a switched neutral.

The only place in the NEC where I found a prohibition on circuit breakers was in the general requirements; Section 380-2, where it states that switches or breakers shall not disconnect the GROUNDED conductor. Note that the requirement is for the GROUNDED, and does not mention NEUTRAL conductors.

Remember, in a RV, the ground connection is made at the shorepower pedestal, so potentially either the BLACK or WHITE wire in the RV could become the hot side (depending on whether or not the pedestal is mis-wired). So which side is truly neutral? Neutral can be either wire, depending on the correct or miswired shorepower wiring.

There is also an exception in the NEC (Exception1) in section 380-2 that states a circuit breaker on the GROUNDED connection is permissible if all conductors are disconnected with a switch or circuit breaker simultaneously. So then, Exception 1 explicitly permits a circuit breaker on the neutral side.

Exception 1 is commonly done in boats as the hot and neutral connectors are connected together with a bail, so that if one side of the breaker is flipped, then both sides get flipped.

Like this:


(the top two breakers are the hot and neutral side of the main breaker)

In fact, there are actually 2 pole breakers available explicitly for this purpose (breakering both hot and neutral simultaneously). I had one in my last boat.

So in my view, it is certainly indeed permissible in a RV according to the NEC to have both hot and neutral breakers as long as they are tied together so they simultaneously trip.

Since I am retired, I don't have the funds to buy a current copy of the NEC, so my references are for the older version, which admittedly is outdated. I would be interested to see where newer versions of the NEC might differ.

In the boating world (which for purposes of this discussion is a parallel to the RV world as the same unsafe conditions can occur):

USCG Regulation (which is actually federal law) 33CFR183.455 requires that all ungrounded circuits be overcurrent protected. It is also backed up by the ABYC (American Boat and Yacht Council E11.7.2.2.1.1), which is the marine industry's version of the RVIA.

Again, the reference is to UNGROUNDED and not Hot/neutral.

So then, we have one industry that is complying with industry and gov't standards (boats) that uses a dual breaker, and another industry (RV) that uses a single breaker for the same safety condition.

So why the difference?

I can only conclude that the RV industry is interpreting the NEC differently than the marine industry. Perhaps the RV industry is meeting minimum standards, but not sufficiently to ensure safety in my view, and certainly not best practices.

So, are boats built better/safer than RV's? I know my answer to that. In my RV at least, there are plenty of examples of shoddy wiring - both in design and execution - that are far from "best practices".

In conclusion, ask yourself the following:

1. are their shorepower pedestals in campgrounds that are mis-wired (hot and neutral reversed)?

2. is it an unsafe condition to operate a RV in this situation whereby the potential exists that you have an ungrounded current carrying conductor that is not protected with a breaker?

3. does the NEC permit wiring techniques (by breakering hot and neutral) to prevent such a safety issue (see NEC 380-2 Exception 1)?

This is still a huge safety issue in my view. At minimum, I encourage all of my RV brethren to invest in a device to check the state of the shorepower connector prior to connecting your RV to it.

[jmsokol]

Originally Posted by FW28z

I am going to have to disagree here.

I have an older copy of the NEC, so forgive me if my information is not up to date....


In conclusion, ask yourself the following:

1. are their shorepower pedestals in campgrounds that are mis-wired (hot and neutral reversed)?

2. is it an unsafe condition to operate a RV in this situation whereby the potential exists that you have an ungrounded current carrying conductor that is not protected with a breaker?

3. does the NEC permit wiring techniques (by breakering hot and neutral) to prevent such a safety issue (see NEC 380-2 Exception 1)?

This is still a huge safety issue in my view.

The marine industry has it's own set of rules, and definitely more safety issues than an RV on the dirt. The most notable danger being gradient voltages extending out from freshwater docks where a boat's ground system has become energized. That gradient can extend out dozens of yards and paralyze any swimmers in the area, causing them to drown without actually being electrified. RV's will have a hot-skin condition with a compromised grounding system. Certainly still dangerous, but only with direct contact.

But to your point about Ground-Neutral Bonding, remember that an RV's circuit breaker panel is treated like a sub-panel in a house, NOT a service panel. So the RV is depending on the pedestal outlet to provide the G-N bond. And the pedestal is also treated like a sub-panel, with its Neutral floated from the Ground, and dependent on the main service panel to provide the G-N-E bond. The reason for this is that the EGC grounding conductor must never carry load current, ONLY fault current.

So can pedestals have their Hot and Neutral wires reversed? Certainly it's possible, but definitely a code violation. And while it appears dangerous, by itself will not cause a hot-skin condition. The hot wires in the RV will now be a ground potential, and the neutral will be at 120-volts, but because the ground is isolated from the neutral, it won't leak current to the chassis. I'm advocating a yearly (or at least semi-yearly) test of all campground and marine pedestals for proper voltage, polarity and grounding. But that's a long way off.

As far as disconnects, from everything I've read in the most recent NEC code, you can only switch the neutral (via a circuit breaker) if ALL conductors are switched, including the EGC (Equipment Grounding Conductor - commonly called the safety ground). So you would need a 3-pole switch, not just a 2-pole switch. Neutrals are not Over Current protected in residential, commercial and RV wiring because of the danger of an neutral opening up and allowing the internal wiring to bias to 120-volts, including the internal neutral conductors.

BTW: The latest NEC is available online for free, so that's one resource where you can continue your studies. But I'm working with an NEC sub-commitee right now on RV grounding issues, and there's never been a discussion about adding a double breaker to open the neutral. Not going to happen, and if you do it yourself you'll be in violation of the RVIA build codes.

Again, the marine industry is different so you can't apply those rules to an RV situation. But I don't see where adding OCP to the neutral conductor will add any safety at all to an RV. Under what situations do you see it being safer?

[FW28z]

Understand that I am talking strictly about unprotected conductors from mis-wired pedestals in my discussion, not stray currents. Mis-wired shorepower pedestals is the situation where I see it safer having a dual breaker.

Do you, and in your work with the RVIA, have any concern about mis-wired pedestals, and you do not see it as a potential safety issue?

While it won't cause a hot-skin connection, you need to think beyond that, as it can be very dangerous should a short occur. Otherwise, why use any breakers at all?

If Connie Camper plugs in her faulty toaster into a reversed-wired RV, well, there you have it.

Certainly, you can see how a reverse-wired pedestal would cause the neutral (which would now actually be the hot wire) to be both ungrounded and unprotected within the RV?

If you are on the RVIA committee, perhaps you should discuss dual breakers. You should at least look at the potential for shorepower pedestal mis-wiring. And perhaps you might learn how the boating industry handles shorepower mis-wiring.

At the very minimum, why not adopt a requirement for a reverse-polarity indicator on the power panel? That should be a no-brainer minimum standard practice, as it costs less than a dollar to add a Normal/Reversed LED to a panel.

In reality, there are more similarities than differences between RVs and boats. The major difference being the boat system includes a dual breaker to protect against mis-wired shorepower pedestals, reverse polarity indicators to indicate when a reversed panel situation exists, and sometimes a galvanic isolator, which prevents corrosion from galvanic current when in the water.

In both boat and RV systems, the neutral-to-ground connection is made at the shorepower pedestal, not in the on-board power panel.

Fact is, I have seen some RV parks that use MARINE power pedestals!

Reversed wired pedestals do occasionally exist in marinas, and if RV parks are built anything like marinas (especially mom-and-pop operations), there are likely a few reversed pedestals out there. In my view, this is a dangerous condition in both situations.

The problem is - you don't know how many reversed wired pedestals are out there, so you cannot go on the assumption that they do not exist

So we need to establish two facts:

1. that reversed wired pedestals do exist.
2. that reversed pedestals result in the RV's neutral wire to become an unprotected non-current limited ungrounded current carrying wire. This is a dangerous condition.

With those two assumptions, the real issue with both boats and RVs is that you cannot control the "shorepower - cable - RV panel" connection. If you could - say like in a house - then that situation is always static, so you can wire sub panels with the assumption that the neutral wire is grounded.

However, the "shorepower - cable - RV panel" connection in boats and RVs is dynamic. You cannot control this connection as it is always changing. And since you cannot prevent encountering a mis-wired shorepower pedestal, you must anticipate this condition and take measures to ensure an unsafe condition does not exist if/when it occurs.

I don't know that much about RVIA (other than it's a industry trade association), but I would hope they are concerned about these safety issues.

[Beacher]

My very first stick house, (a very sturdy built in 1922 stucco and lath bungalow), had "Hot Skin"!


When you took a shower, you would get a mild shock when turning the tub knobs on or off. And, you could hear arcing, and smell ozone, when the sink faucet dripped!


A week after we moved in, I really noticed it and called the home warranty folks who sent an electrician. The problem turned out to be that the front porch light was shorted to the house stucco! Weird and "shocking"!