RV Electricity – No~Shock~Zone by Mike Sokol – Issue 11

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Issue 11 • September 30, 2018
MIKE SOKOL, editor

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Welcome … 

Stray Voltage Patrol Update
 
Here’s a quick update on the Stray Voltage Patrol. We are now up to 256 signed-up members, with at least two dozen of them appearing to be super qualified – with electrical engineering degrees, master electrician licenses and RV technician backgrounds. So we have a solid base of more than 100  entry-level SVPers who can do basic testing with a Non Contact Voltage Tester, another hundred ready to meter their own and nearby pedestals, and maybe 20 or 30 who are qualified to actually open up panels and take a look inside (with the campground’s permission, of course). 
 
I’ve had nearly 100 reports in the last two months, some of which I’ve shared with you as part of my articles. As you can see, I’m receiving a lot of new questions I would never have thought of, which is great. So I’m extremely pleased with the response so far. 
 
Jess and Kim (the Digital Dynamic Duo at RVtravel.com and RVelectricity.com) have just finished transferring over RVelectricity.com from the developmental to the live site, and I’ve begun populating it with many of my previous articles. We should have all the rough edges off of it in a week or so, and then I’ll post another hundred articles. As soon as this important work is done, team KayJay (as I like to call them) will begin work on making the SVP reports online instead of me pasting them into a spreadsheet one report at a time (ugh). 
 
So this is all going great, even though it’s taking a bit more time than I would like. But have no fear, the Stray Voltage Patrol will be totally up and running in October and we can begin sorting through data. And then the fun will begin.  

Let’s play safe out there… 

 

P.S. And just a quick reminder 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.


Save your propane! Easily convert to electric heat!
SAVE $$$
! Until now, the standard for heating recreation vehicles of all types has been to use bottled propane (LPG). With the CheapHeat™ system there’s a better option. Now you have a choice to change the central heating system between gas and electric with the flip of a switch. When you choose to run on electric heat rather than gas, your coach will be heated by the electricity provided by the RV park. Learn more.


Clean Up, Clean Up, Everybody Clean Up…. 

This is a really important maintenance step that ALL campgrounds need to perform after any flooding that puts their pedestals underwater. Considering all of the campgrounds on the East Coast that were flooded out by Hurricane Florence, it’s an important safety step that shouldn’t be overlooked. 

Read more here.

Email me at mike (at) noshockzone.org with your questions.


Truma AquaGo®: Instant, Constant and Endless Hot Water
trumalogoThe 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.


Industry Updates

EC&M magazine releases free e-book on why electricity and water don’t mix…
This may not be casual reading for everyone, but if you have a boat dock, swimming pool or hot tub with any type of electric power near it (including lighting), then this free e-book from Electrical Construction & Maintenance Magazine on grounding and bonding around water is a great resource, especially for your electrician doing the wiring. 

Yes, you’ll need to enter a little information about yourself and they’ll email you a free pdf of the e-book, but it has some great case studies on electrocutions involving water and electricity. So if you’re an advanced Stray Voltage Patrol member (you know who you are), this is a must-read.  

Case studies to prevent disasters
There’s no doubt that more careful inspection and stringent maintenance/testing of bonding and grounding systems near or in bodies of water are crucial for the everyday safety of swimmers and those working in environments around water that could become electrified and pose a safety risk. Corrosion and deteriorated bonding and grounding connections often expose swimmers to shock and electrocution hazards. Many times, these faulty connections can be traced back to the use and installation of non-listed connectors and poor workmanship, which ultimately lead to a breakdown in the overall protective system.

So whether it’s a pool repairman’s electrocution, a town being forced to close its pools after shock incidents are reported, or unsuspecting boaters or home owners receiving fatal electric shocks in or around water, the content in this e-book takes readers through National Electrical Code revisions that affect these types of scenarios, presents the electrical theory behind the requirements, and allows electrical professionals to make more informed decisions about whether they are doing enough to protect the public from harm.

Instant Download Here!



Survey Question
Do you use a separate battery tender on your RV over the winter downtime?


Your RV is generally your second largest physical asset. Protect it!
Home Electrical Box: 50-30-20 amp surface mount box • Breakers & receptacles included • Outdoor rated • UL listed • Pedestals also available. 30 & 50 Amp Surge Protector & Reverse Polarity: Continuously monitors & displays voltage & amp draw (RMS). Tests for & indicates: Reverse polarity • Exclusive open neutral inside the RV • Miswired pedestal • High neutral currents • Surge protector. Contact us at 800-500-2320 or RVpowerOutlet.com.


Click image to enlarge.

Last month’s survey results:
What kind of batteries are you using for your RV house power?
The survey shows that the vast majority of RV owners (78%) are still using traditional flooded cell lead-acid batteries, and 19% have the newer AGM batteries that don’t require any maintenance. I think the AGMs are way more practical for RVers since not maintaining the water level in traditional lead-acid batteries is a major killer.

However, the new Lithium Iron Phosphate batteries are stuck at 3% in the survey largely because of the initial expense and limited number of OEM (original equipment manufacturer) installations so far. However, if you compare the discharge cycle of a LiFePO4 battery (that’s the actual chemical shorthand for this technology, but you can just call it Lithium Battery if you like), you’ll see that Lithium Batteries are smaller and lighter in weight, and they can be discharged by 80% of their capacity down to the 20% level regularly without losing life cycles – while lead-acid batteries should only be discharged down to 50% of  their capacity. I predict that within a handful of years, the same thing that happened when flat-screen televisions killed CRT sales not so long ago, will happen to lead-acid vehicle batteries.   

What’s driving this trend of increased 12-volt battery capacity in RVs? Well, it’s largely the residential refrigerator boom that Chuck Woodbury started writing about last year at RVtravel.com. As a result, I get tons of emails and comments every week about what it would take to run a residential refrigerator in an RV from solar panels and batteries. And my answer has always been that I’m not smart enough yet to write about it.

However, I just made a deal with a major solar panel and lithium battery supplier to send me a bunch of solar panels and batteries, plus I’m being offered test products by a refrigerator manufacturer who’s promoting their marine-grade, 12-volt DC, residential-style refrigerators to the RV market.

That means I’m going to set up a long-term test of solar panels charging lithium batteries, powering a residential refrigerator, using both a 120-volt AC traditional compressor technology powered with an inverter, as well as a 12-volt DC Danfoss/swing compressor powered by the battery directly. Don’t get too excited, since this will take at least 6 months to gather enough data to be useful. But by the spring I should be able to offer a solid engineering opinion of how to do this properly, and not just regurgitate marketing hype. So stay tuned… 


Tools and Other Devices

I had one of these for years and just recently lost it on a gig… 
Funny how good tools can go rogue and walk away from you on a jobsite, isn’t it? I loved my GreatNeck multi-screwdriver with a telescoping magnet right in the shank, but now it’s MIA. Well, in its defense I might have left it up in a ceiling somewhere when I was pulling wires, so if it wants to show back up in my toolbag sometime, all will be forgiven.

In the meantime I’m ordering another one since I really needed the magnet last week. So, if you lose a screw down a crack in the floor, or a wrench down an access hatch in your vehicle, just pull out your trusty GreatNeck screwdriver with the magnet in the telescoping tip, and you’re back in business without mussing your shirt sleeves digging around in a hole. (And it’s only about $12 at Amazon, and well worth it!).


Last Month’s RVtravel.com Posts

• 2018 RV Electrical Safety Seminars update.
The Stray Voltage Patrol is now up to 200 members!
Low voltage report.
Stray Voltage found on call button box on gate!
• Can I add a second surge protector?


Today’s Coupons at Amazon.com
Do you love coupons, those handy things that save you lots o’ money? Did you know Amazon publishes a whole bunch of them every day? There are pages and pages of them on food products, clothing, sundries, toys, electronics, tools, even RV accessories. So go ahead, save some money! Check ’em out.


Q&A’s from Forums

I spend a lot of time on dozens of RV forums answering questions about electricity. Here are three of them from close to home:

From my No~Shock~Zone blog:

A new comment on the postMiswiring a 120-volt RV outlet with 240-volts“:
“I am so lucky that I happened across this site. I am an electrician in Colorado and was called by this client today to wire up his old 1980’s Airstream on his ranch. I looked at the plug and thought, no problem, went to home Depot and bought supplies to wire up that dryer looking plug for 240 volt. I was even going to cut off the old corroded head and put on a new one. Wow, I would have screwed up big time. Now I know what to do. I guess I should go look in the code book but I have a feeling it won’t tell me about this. I’m going to tell all my electrician friends about this and see if any of them are aware. I bet not. Thanks, Mike, for saving me a couple of grand and an endless headache. Please put me on your mailing list.” —Steve N.  

From the RVtravel.com Newsletter:

Q: From Bob P: Your bit on dog bone connectors is very misleading. Your amperage numbers are reversed giving the impression you can use a 15-amp plug to give 30-amp service and 30-amp plug to give you 50-amp service. You can use the 15a to 30a dogbone but you are just adapting to your 30 amp plug, you’ll only be able to get 15 amps, not enough to run a/c but can run a coffee pot and a few lights. The same applies to the 30a to 50a adapter. The fact remains you can’t use anymore current than what the outlet is designed for without causing an over heating and possible fire hazard.

A: From Bear: As I read it, Karin’s question was about using a 50-to-30A dogbone for her 30A RV…not the other way around. Her intention was to get a cleaner contact, I guess, having been told that 50A outlets get less use. First, I doubt they get less use since more and more rigs are powered @ 50A, and 100A are coming down the pike. So there’s that. Second, sounds like she’s aware she’ll only get 30A (since that’s all the dog one will let pass). And third, I personally don’t see any harm in her plan. Go for it, Karin!

A: From Mike Sokol: Bear, I agree there’s no harm in using a 50-amp to 30-amp adapter, but I’m looking at what the National Electrical Code will allow, and what liabilities you might have if there was a melt-down. It should be safe, if a little bit off-code, but I don’t think any inspector would care.

Read more on this topic in the RVtravel.com Saturday newsletter here

From the Stray Voltage Patrol (See Full Report Here)

Describe what you discovered:  Voltage 117 with about 10% of sites filled, but got down to 93 Volts with 85% of sites filled. Very time-of-day dependent as campers turned on AC or cooking loads, but voltage in the 90’s is terrible sag!

A:  So is this bad? In a word, yes. Now, it’s not likely to cause a hot-skin/stray-voltage, nor is it likely to start a fire in your RV. However, it’s very likely to cause many RV air conditioners to either not start or even burn out. Residential refrigerators in the RVs will also have the same sort of issues. Compressor motors tend to be very amperage hungry during startup, and rely on a stable 120-volt power source to get up to speed quickly. I’ve often said that anything below 100 volts can be damaging, and here we have an example of 93 volts. So, use at your own risk since I don’t think the state park is going to pay for your new air conditioner or refrigerator. 

Update: I just received an answer from Dometic engineering on the effect of very low voltage on air conditioners, and here’s some preliminary data which I’ll decode later. But there appears to be more in the mix than just start-up current. It also appears that the run current on the compressor goes up as well. 

The following is a pair of reports from Dometic using the same air conditioner at 115 and 105 volts

Click image to enlarge.

Note that there IS a 12% INCREASE (14.95 Amps to 16.87 Amps) in current draw from the compressor motor at 105 volts (bottom right graphic) compared to 115 volts (top left graphic), and a 6% DECREASE in the current draw of the fan (2.86 Amps to 2.73 Amps) as well as the fan RPM going down when on low voltage.

Click image to enlarge.

My initial reaction to these numbers is there will possibly be a substantial increase in temperature of the compressor motor windings when powered by too-low pedestal voltage, but the fan motor will just slow down in speed and probably won’t overheat. However, I’ll know more after I have a phone conference with engineering.

This is getting really interesting since I’m now getting access to internal engineering data from the manufacturers which saves me a bunch of time and money setting up my own experiments. I’ll write more later about what’s happening when you’re running your RV on Very Low Voltage.  

Mike

Email me at mike (at) noshockzone.org with your questions.


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 


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

The Good Old Days….
By Mike Sokol

So, when was the best music recorded by the best artists and what kind of foods do you gravitate to? Tell me the year you were born and what state you grew up in during your teenage years, and I can probably venture a pretty good guess. To make an educated guess at your music tastes all I have to do is add 14 to the year you were born, and look at the top 100 songs charting that year, and voila… So let’s take my birth year of 1954, add 14 to get 1968. That’s the year I “discovered” music – around the age of 14, as it were. Read more 



STAFF

Editor: Mike Sokol. RVtravel.com publisher: Chuck Woodbury. Managing editor: Diane McGovern.

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..

Mail us at 9792 Edmonds Way, #265, Edmonds, WA 98020.

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This newsletter is copyright 2018 by RVtravel.com.

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George Forrest
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George Forrest

Found it very interesting aJobnd look forward to new issues as they come out. I am looking forward to the usage of solar power instead of electrical. Opens up many new options to RVers. Good

Tommy Molnar
Guest
Tommy Molnar

So now I find that the new “LiFePO4” batteries may not be the absolute panacea for finding battery nirvana? Guess I’ll sit back with my ‘ancient technology’ golf cart batteries and see if this battery choice changes as time and technology improves. Since I’m SO anal with my batteries (checking water level and keeping them charged), I’ve never had any frozen battery experiences – even here in Northern Nevada.

Bill
Guest
Bill

Answered No because we have never not used our motorhome in winter. Have a smart charger for the house batteries, trickles to chassis batteries, and also a small solar panel for chassis batteries.
By the way, 12 volt compressor refrigerators have been available for many years. Had them in Xplorer Class Bs from the 70s and 80s.

Bil
Guest
Bil

Also never have had batteries freeze. Pipes yes, but not batteries. Have been in snow and ice storms, but never in sub-zero weather though.

Wolfe Rose
Member
Wolfe Rose

Never being in really cold weather would be a huge caveat to never freezing batteries…lol. Here in the Northeast, I’ve frozen 5 car/truck batteries in the last 3 years. If I don’t drive every few days or keep all the batteries on chargers until I drive, February is MURDER. It seems -20F is too cold for anything but 99% charged batteries. My 3-season trailer batteries do better because I *remove* them to warm storage when below +20 or so.

Richard Martin
Guest
Richard Martin

Mike Sokol
where can I get a repair manual for a 12.5k Onan generator to replace the stator, also would there be any other damage I would need to check on the unit? before putting it back into service.

Thank You Richard Martin

Mike Sokol
Editor

Not sure where to get the manual. I’ve talked to Cummins-Onan a few times casually, but I don’t have a working contact there. However, be aware that all generators have some sort of voltage regulator circuit, so if you replace or adjust anything you’ll want to carefully check the output voltage before connecting it to your RV’s electrical system.

Loren Robinson
Member
Loren Robinson

Couldn’t answer your question this week since we don’t leave the motorhome plugged in while stored. We have three 80 watt solar panels and a good controller that keeps the batteries (two six volt ‘golf cart’ batteries) charged. I check the acid level every month and the last set lasted eleven years.

Tommy Molnar
Guest
Tommy Molnar

I’ve got 700 watts on the roof of our trailer, but it feeds only two Trojan T-145’s. I wish I had more room for more batteries, but alas, I don’t. Plus, these suckers are HEAVY! I was barely able to lift them up and put them in place. But they do the job (no residential fridge, not using the a/c, etc). The real reason for all those watts on the roof is for the days when the sun doesn’t make it out. I can still get a full charge in our batteries. Someday, when the lithium batteries are affordable to… Read more »

Dick and Sandy near Buffalo, NY
Guest
Dick and Sandy near Buffalo, NY

After over 13 years with our first two Class A rigs and the pastr 2 years with our new Class A motor home, of the problems associated with checking and topping off 4 wet cell house batteries with distilled water, I had enough. I changed out those wet cell batteries with a new set of AGM maintenance free batteries. That is I don’t have to concern myself with the fluids inside the batteries. I still have to maintain the cleanliness and tightness of all the battery terminals as well as monitoring the charging and discharging rates. But now I an… Read more »

Dr4Film ----- Richard
Guest
Dr4Film ----- Richard

I think more RVer’s would be interested in this study using a typical medium size residential 120 VAC powered through a PSW Inverter versus using a 120 VAC/12 VDC compressor type fridge which is fairly new to the marketplace and quite small too. Plus, most people cannot afford Lithium batteries sized for most RV’s versus AGM’s or wet cell batteries. I have been using a Samsung RF-197 fridge in my Class A coach since 2012 but not powered just from solar panels and batteries. I would have to fill up my entire roof with solar panels and install 4 additional… Read more »

Mike Sokol
Editor

I’m setting up a test with a standard residential 120-volt compressor refrigerator powered by an inverter, as well as a medium size, 8 cubic foot swing compressor running on 12 volts DC. Plus I’ll be trying the standard flooded cell lead-acid batteries as well as AGM and Lithium batteries. I can get as many solar panels as I want, so I’ll try this experiment with a small number of panels (1 or 2), and work my way up. I have a number of data logging meters, so a week or so on each configuration should give me some real data… Read more »

Dr4Film ----- Richard
Guest
Dr4Film ----- Richard

That appears to be a better evaluation than what was described in your newsletter. Thanks for the clarification.

Mike Sokol
Guest
Mike Sokol

Since I began pitching this idea to RV parts suppliers late last week there’s been a lot of interest, so I’m expanding the scope of the test. I have the background to design and run this sort of experiment, so this empirical data will be good for the entire RV industry as well as my readers. Real data beats random guesses any day…

Al Simons
Guest
Al Simons

Combining last month’s survey with this month’s, what is needed to properly overwinter LiFePO4 batteries? I’ve read they should not be charged when below freezing.
Thanks,
-Al

Mike Sokol
Guest
Mike Sokol

That’s a great question. I’ll ask one of my battery manufacturers for a Lithium Battery charging/storage protocol. I have a guess right now, but need confirmation.

Wolfe Rose
Member
Wolfe Rose

Re: LIFe batteries (really, any LiXX), you are generally correct on the bottom line. You can discharge LiXX below freezing (at diminishing C rates), but they functionally won’t accept any charging. Whether this actually damages them varies between manufacturers (most say not, but its still pointless). Having frozen endless lead batteries, I’d just take them inside on principle and paranoia.

I think BatteryUniversity did a write up on frozen LiXX charging, explaining it better than I will.

https://batteryuniversity.com/learn/article/charging_at_high_and_low_temperatures

Wolfe Rose
Member
Wolfe Rose

Actually, since I can’t edit, I’ll update… all the manufacturers I work with have now changed “please don’t” to “absolutely don’t.”

“Charging below freezing at rates higher than 0.01C are likely to form metallic lithium at the anode. This damage is permanent, and makes the cell subject to severe vibration damage. We do NOT advise charging at these temperatures. “