Issue 6 • April 29, 2018
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Mike to speak in Indiana in May
Join Mike Sokol at the RVillage Rally in Elkhart, Indiana, May 17-21. He will teach several seminars and be around for the entire event to “talk RV electricity” with the 1,000 or so RVers who are expected to attend. Learn more about the rally here! You’re invited!
By Mike Sokol
Welcome to issue #6 of my RV Electricity newsletter from RVtravel.com. This is our 6-month anniversary. In this issue I’ll continue my series on electrical terminology as it relates to RV power connections and safety, plus I’ll cover how to attempt to report a campground with dangerous wiring to authorities.
I said “attempt” because every state, county, city and local municipality interprets the National Electrical Code (NFPA-70) in their own way, and each one has something (or someone) we call the AHJ, for Authority Having Jurisdiction, who sits in judgment of the code in their district. I can’t provide the phone number of the agency you need to call to report a code violation, but I can tell you how to get started on the process.
Also, I keep getting tons of comments and emails relating to RV electrical hookups and safety, which really helps me steer this ship and cover the topics you’re concerned about. I can’t answer every one immediately, but I now have a pretty long list to work on. So please keep those emails and comments coming, and pass on this newsletter to everyone you know who owns an RV and ask them to subscribe to it HERE. All RVs, both great and small, use electricity nowadays, so it’s your responsibility to use electric power responsibly and safely.
Now, on to voltage. This concept is key to understanding everything about electricity, so put on your learning caps and let’s begin. Class is now in session …
What is Voltage?
You asked for it, so here’s my full article on voltage and how it relates to shocks.
While RVs as wired from the factory are inherently safe, they can become silent-but-deadly killers if plugged into an improperly wired extension cord or campsite outlet. This is because RVs are basically a big cage of metal insulated from the ground by rubber tires. It’s up to you to make sure the frame and body of your RV are never electrified due to poor maintenance, bad connections or reversed polarity in a power plug. This so-called Hot-Skin problem is what causes a tingle when you touch the doorknob or metal steps of your RV while standing on the ground.
I can remember teaching myself basic electricity starting when I was 8 years old. It seemed like such a mysterious force that could do most anything from light up a bulb to shock you if you touched a wire. I wanted to know all about it. So, for the next few years I read every encyclopedia entry, every book I could find in the library, and every Popular Science magazine I could get my hands on, plus ran “electrical experiments” in my bedroom – which terrified my siblings and parents.
By the time I was 14 years old I had read a ton of books and built all kinds of tabletop demonstrations. And I finally understood the basics of DC electricity and how it worked. At that time I was lucky enough to be the recipient of my uncle’s complete set of 1950s U.S. Navy electrical training books on circuit designs for radios and televisions. So, by the time I was 16 I had completed the U.S. Navy design course and began building my own tube guitar amplifiers from parts I found at the local landfill. That interest is what launched my career in electrical and audio engineering. You could say that I grew up with electricity and I’m still learning about it. I’ll teach you about electricity the same way I learned it myself 50 years ago.
Now, most RVers really don’t want to learn about electrical engineering. However, everyone should be able to learn how to test for and avoid electric shocks or electrocution at a campsite. With that in mind, there are some novel ways to learn about electricity that should work for the casual RVer. I learned electricity myself by thinking about water pipes and pressure, so that’s how I’m going to teach you. Your feedback is encouraged.
Why do we get shocked? (What is this volts thing?)
What’s so hard to understand about electrical shocks in general is that they don’t seem to happen for any obvious reason. For instance, you can watch a bird on a power line that’s not being shocked, yet sometimes touching a power tool yourself while standing on wet ground can bring you to your knees. Just why is that?
Voltage = Pressure
Well, the first thing to understand about electricity is the concept of voltage. Think of voltage as electrical pressure, just like the pressure in a tank of water. In a tank of water we measure pressure in something called PSI (pounds per square inch), which will of course increase if we get a deeper tank. This pressure is caused by the pull of gravity from the Earth, and if you hook up a hose to the tank, the water will flow toward the ground. So while 10 PSI of water pressure from a short tank might give you a trickle of water when hooked up to a hose, 100 PSI of water pressure from a really tall tank gives you a stream that will spray much farther.
Pressure difference produces flow
Water — and electricity — tries to flow to the side of least pressure (or voltage potential). You can imagine that if a pipe is connected between two tanks with exactly the same water level and pressure (say, 100 PSI) there will be no flow of water through the hose. It just sits there and does nothing because the system is equalized. However, if you connect one tank with 100 PSI of water pressure to another tank with 10 PSI of water pressure, water will flow from the high tank to the low tank. We measure this water flow in gallons per minute.
Completing the circuit
The same thing happens with electricity. You’ve often heard of “completing an electrical circuit,” but think of it as different electrical pressures. Getting back to the bird on the power line, if both of the bird’s feet are on the same wire, they’re at exactly the same electrical pressure (volts). Because they’re at the same pressure (voltage), there’s no electrical current flowing through the bird. If, however, our feathered friend is unlucky enough to touch one foot on a power line and a wing to the grounded metal power pole, then his one foot will be at 11,000 volts (think PSI of water pressure) and his wing at 0 volts (think an empty tank). This will cause a LOT of current to flow through the bird, which we’ll measure in amperes. And, indeed, 11,000 volts across a pigeon can cause a bird explosion.
Hot skin shocks
Now, consider your RV. Sometimes you may feel a shock when you touch your hand on the doorknob and sometimes not. What’s happening is that there could be an electrical voltage (think pressure) on the body of the RV, which is waiting for some different electrical voltage level to head towards.
If your entire body is inside the RV then, like the pigeon, every part of you is at exactly the same voltage. And, like the pigeon, there’s no current flow and you feel no shock. However, if one foot is on the ground at essentially zero volts and your hand is on the door of your RV that is at 100 volts, you become the pipe and the different electrical pressure (volts) will push current (amps) through your hand, arm, chest cavity, torso, leg and foot. If your foot is on dry ground there might be so little flow that you may not even feel it. But stand on the damp ground with a wet shoe, and you’ve made a zero-voltage connection to the ground with your foot. In that case, a lot of current will flow through your body if you simultaneously touch a doorknob or metal step that’s at 100 volts or so.
Heart to heart
The dangerous part is when this electrical flow goes through your chest cavity since right in the middle of you is your heart, and hearts don’t like to be shocked. That’s because the beat of your heart is controlled by electricity, which comes from your own internal pacemaker. And just like a clock radio can be scrambled by a nearby lightning strike, even a small amount of electrical current passing through your heart can cause it to start skipping beats and cause a heart attack. Just how little? Glad you asked.
I’m sure by now you’ve seen the 20-amp marking on a circuit breaker. That means it can supply up to 20 amps (amperes) of current flow when asked to do so. Again, you can think of it as possible gallons per minute of flow, and amps are indeed a count of electrons per second flowing through a wire (think pipe). Much more on that later, but under the right conditions it takes less than 10 milliamps of electrical current to cause your heart to go into fibrillation mode. That’s just 10/1000 of an ampere or 0.010 amps of alternating current to cause what’s essentially a heart attack. Since your body has a hand-to-hand resistance of around 1,500 ohms (more on ohms later), it takes as little as 30 volts of alternating current (AC) to stop your heart if your hands and feet are wet.
On the strange but true side of the coin, while 60 Hz (cycles per second) alternating current (AC is what comes out of your wall outlet in the U.S., but Europe uses 50 Hz) can cause your heart to go into fibrillation and stop pumping blood, the rescue crew will use direct current (DC) of several hundred volts to reboot your heart and get it beating regularly again. That’s what they’re dumping through the paddles placed on your chest — direct current from big capacitors like you see charging on the TV dramas before they yell “Clear!”
Play it safe
The first rule of staying safe from electrocution is to keep your heart out of the current flow. You can see that getting shocked from hand to hand or hand to foot is about as bad as it can get. That means if you’re plugging in your RV plug to a campsite receptacle with one hand, the last thing you want to do is hold onto the metal box with your opposite hand or be kneeling on the wet ground. If you have two points of contact and something goes wrong (like you touch a bare wire), the current will flow to your opposite hand or feet, passing through your heart in the process. So always turn off the circuit breaker when plugging or unplugging your campsite power. Not doing so is to invite death by electrocution, and nobody wants that.
- Use only one hand to plug or unplug any power cables.
- Turn off breakers in the pedestal before plugging or unplugging campsite power.
- Never stand or kneel on wet ground while making electrical hookups.
- If you feel a shock from any part of your RV, do not get into your RV. Shut off the pedestal circuit breaker immediately, unplug your shore power from the pedestal, and alert the campground manager immediately.
P.S. And just a quick note that this newsletter is made possible by the voluntary pledges of the readers of RVtravel.com. We could not bring this to you without their support. If you deem what we provide to you here and at RVtravel.com to be of special value and would like to be a part of our effort, please consider pledging a voluntary subscription. More information is here. We will include you in special emails, articles and videos exclusively for our supporters.
Easy way to add water to your batteries!
Never, ever, let your automotive or RV deep cycle batteries run out of water. Here’s a simple way to keep them topped off for maximum performance and long life. Just use this syringe with distilled water. So easy. Learn more or order.
How to report dangerous campground wiring
I had a really interesting report and question from a reader last week. He asked me to run the edited version by him before publishing any details, so I’ll do a full article on his question in the next issue. But I think it’s important enough to bring up the subject here.
So what if you find a pedestal at a campground that’s obviously wired incorrectly, and maybe even dangerously? Do you just ask to move to the next campsite and not worry about what you left for the next camper in that site? Do you report it to the campground maintenance guy and insist he correct the problem? Or do you take it to a higher authority like the local electrical inspector and warn them about potential code violations? And if you choose the last option, just WHO is the inspector in charge?
Well, I’m researching the last question since there’s no simple answer. The key thing to understand is that as I stated in the top article, the National Electrical Code is really just a suggestion, not a law. So each state, county, city and local jurisdiction has an Authority Having Jurisdiction on how code is applied in their own jurisdiction. The AHJ is the Electrical Inspector you’re looking for, but may be hard to find.
But a good place to start is the local sheriff or building code office. The tax office is another place to find who’s in charge of this AHJ function. But the reason I’m doing research is that there appears to be dozens or even hundreds of differences from state to state. For example, in many of the northeast states the electrical inspector must hold a Master Electrician License, while in several southern states I’ve studied the Electrical Inspector doesn’t need any kind of Electrician License at all. And the act of pulling a permit for electrical wiring also varies from state to state and locality to locality. Some need it, and some don’t for campground wiring.
So I don’t have a solid answer just yet, but I’m working on it. And RV Travel editor Chuck Woodbury and I have talked about creating a database of campgrounds with questionable wiring which you could update and refer to. Stay tuned and we’ll see how it goes in the near future. —Mike
Email me at mike (at) noshockzone.org with your questions.
Truma AquaGo®: Instant, Constant and Endless Hot Water
The revolutionary Truma AquaGo® hybrid instant water heater provides instant, constant and endless hot water. The Truma AquaGo® is the only RV water heater that can be decalcified to extend product life and maintain performance. And its “Easy Drain Lever” makes winterization simple. Use the Truma AquaGo® to replace any 6 – 16 gallon water heater. Find a dealer at www.truma.net.
Lithium-Ion charging systems will soon be available for your current RV
LITHIUM BATTERY POWER CENTERS FOR RV INDUSTRY
Progressive Dynamics, Inc. has developed several models of 12- and 24-volt power centers for RVs, designed to meet the requirements of lithium ion phosphate batteries and provide the Constant Current Constant Voltage charge profile required by lithium battery manufacturers. Lithium ion batteries require special balancing circuits and chargers to prevent overcharging or discharging a cell beyond its specifications.
Standard features of Progressive Dynamics’ lithium ion battery power centers include reverse battery protection, electronic current limiting, low line and high voltage protection and a variable speed intelligent cooling fan. Units also deliver filtered DC power to the lithium ion battery to ensure the built-in electronic balancing circuits operate properly. Output voltage can be factory adjusted to meet OEM requirements for various lithium ion battery chemistries and voltages.
Progressive Dynamics also provides Lithium Battery Power Center units for RV owners, dealers and manufacturers to easily update their current system to a Lithium Ion Battery System. There are many advantages of using lithium ion batteries including no battery maintenance and faster recharge from both the power centers and solar charging systems. A lithium 100AH battery can be fully recharged in 2½ hours compared to 6-12 for lead/acid batteries. They also provide a longer battery life, with a recharge cycle up to 5,000 times, compared to 300-400 cycles for lead/acid batteries, and lithium ion batteries do not have to be charged during storage. Lithium ion batteries deliver up to three times the energy of a lead/acid battery within the same space and at approximately half the weight.
Progressive Dynamics, Inc. is a privately owned corporation, providing products for RV, specialty and marine industries which are designed, engineered and assembled in the United States and tested prior to any sale. Each product is provided with a warranty and backed by superior customer service.
For more information contact Progressive Dynamics, 507 industrial Rd., Marshall, MI 49068. Phone: 269-781-4241, Fax: 269-781-7802. E-mail: email@example.com, Technical Help: firstname.lastname@example.org.
Just add enough solar cells and a charging system and you can go off-grid without a generator. —Mike
Klein Tools Electrical Test Kit — Essential!
Every RVer should have this aboard their RV. The highly-rated, updated electrical test kit contains MM300 (manual-ranging digital multimeter), ncvt-1 (non-contact voltage tester) and the RT105 (receptacle tester). The ncvt-1 automatically detects standard voltage in cables, cords, circuit breakers, lighting fixtures, switches, outlets, and wires. The RT105 detects the most common wiring problems in standard receptacles. Learn more at Amazon.
I always carry at least two of these folding utility knives with me, and they come in handy all the time. I like the folding type with a blade lock, and you can store a few spare blades in the handle. Don’t try to carry one through airport security, though, as I almost lost one last week on my flight to Paris. But the TSA guy was nice enough just to take the blades and let me keep the handle. You can get them at any big box store or on Amazon here.
Last Month’s RVtravel.com Posts
RV Electricity posts in last month’s RV Travel Newsletters:
• Why do hot-skin shocks occur?
• Avoid an RV electrical blowout with smart surge protector.
• Deciphering the 3-light outlet tester.
• Do I need an “intelligent” surge protector for 50-amp shore power?
• Can I add an AFCI in my RV?
Last month’s RV Daily Tips Newsletter RV Electricity Tip of the Day:
• Can your RV park help if you have a heart attack?
• What are these NEMA outlets you speak of?
• Will your RV protect you from a lightning strike?
• What does a battery disconnect switch do?
Don’t come up short!
Sometimes your 50-amp power cord is not quite long enough! That’s when this 15-foot extension cord will come in very handy. Sure, you can use a wimpy orange extension cord with an adapter — and risk burning up the cord, ruining appliances, or maybe even burn up your rig! With this cord along you’ll be all set. Learn more or order.
Q&A’s from Forums
I spend a lot of time on dozens of other RV forums answering questions about electricity. Here’s one:
From the Schoolie Forums:
Q: Hi Mike: I have been reading your tips on schoolie websites. I am a little confused as to how to physically accomplish separation of the neutrals and grounds and actually ground to RV frame. The box I have has a single bus for grounds and neutrals; it is insulated from the panel box. Do I need to add a separate bus just for grounds and ground that bus to the RV frame? Or is bonding the existing bus to the box and then grounding the box to the RV frame adequate? It gets confusing. Any clarification would help. Thanks. —Mark H.
A: Hi Mark: You’re on the right track, but backwards. What you need to add is an isolated neutral bus bar in your panel, terminate all the ground wires to the original “ground” bus that’s bonded directly to the box, and terminate all the neutral wires to the new “neutral bus.” When you’re finished wiring and before you apply any power, you should meter between the neutral and ground buses and measure at least a few hundred thousand ohms, and typically up to 10 million ohm or so, depending on dampness, quality of insulation, etc. Please let me know if this makes sense. —Mike
The best book on RV electricity, hands down!
RV Travel contributor Mike Sokol is America’s leading expert on RV electricity. Mike has taken his 40+ years of experience to write this book about RV electricity that nearly anyone can understand. Covers the basics of Voltage, Amperage, Wattage and Grounding, with additional chapters on RV Hot-Skin testing, GFCI operation, portable generator hookups and troubleshooting RV electrical systems. This should be essential reading for all RVers. Learn more or order
I was out of the country last week for my 30th wedding anniversary with my wife, Linda. In fact we flew to Paris and had dinner on the Eiffel Tower on our actual wedding date.
You didn’t know I like French food, did you? Here’s my child bride and me under the Eiffel tower.
Camco Store at Amazon.com
There isn’t much you need for your RV that Camco doesn’t have. If you think we’re kidding, then click through to the Camco store on Amazon where you’ll find some of their best-selling products — all for your RV or for you to make your RVing better. Click here and you’ll feel like a kid in a candy store.
Road Signs will return next issue
after I decompress from my trip to Paris.
Editor: Mike Sokol. RVtravel.com publisher: Chuck Woodbury. Managing editor: Diane McGovern. Staff writer: Emily Woodbury.
Everything in this newsletter is true to the best of our knowledge. But we may occasionally get something wrong. So always double check with your own technician, electrician or other professional first before undertaking projects that could involve danger if not done properly. Tips and/or comments in this newsletter are those of the authors and may not reflect the views of RVtravel.com..
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