Not sure if this should be under Technical, but it certainly autoformers in general have been discussed on here lately. The NFPA, National Fire Protection Agency has a new code for 2020 regarding RV's in campgrounds. The autoformers are putting undue stress on park electrical demands and will not be allowed in use in 2020 according to NFPA. This notice was also on Mike Sokol's website, who is an electrical guru and does seminars across the country in support of electrical systems of RV's.
Time will tell on how this will be implemented, but I can see park owners enforcing this as soon as it becomes an active code violation.
Your input is welcome and any further information I collect, will certainly be passed on, as many on here have a Hughes or other electrical devise to enhance their system.
Interesting. May be a hard policy to "police" in busy RV parks, especially if coach owners don't leave the units sitting out on the ground. I believe Barry & Cindy have extensive experience with the Hughes Autoformer. (See link below for a sample post) Hopefully they will chime in with some (always appreciated) thoughts on this subject.
Progressive industries and Hughes autoformer use together (https://www.foreforums.com/index.php?topic=28750.msg240804#msg240804)
I agree, wish I was parked next to Barry & Cindy to pick their brains! If the Autoformer is out of sight, not sure how they could police that, but from what the article stated, the lack of power at other pedestals may be a good indicator of one running? Possible!
As I write this my buddy is installing my Autoformer and a built in progressive industries 50 amp unit,
The idea that reducing the amps to raise the volts into a single coach does not seem to change the pedestals output,
Am I wrong? Versus at low voltage you turn off your power?
Maybe my coach can run safely on low volts if anyone asked?
Or I don't care if it's damaged from low volts?
Any way for anyone external to know you have a Autoformer installed?
Better to properly wire park pedestals. Then there is no need for autoformers.
Besides, an auto former cannot increase current draw beyond 50A, which is what you are paying for.
By the way, I have a never used autoformer that I got for free. If the park power is whacked out, I'd rather do without. My coach will automatically disconnect in under/over voltage situations.
After searching this is what I found. It looks like it is just to benefit the park owners so they don't have to fix the real problem
https://www.go-usg.com/t-publication-051718.aspx
I tried to comment on the proposed banning of autoformers on the NFPA website. Could not find the proposed rule on there.
This is a bad rule change. They need to make the campgrounds supply the correct voltage and ampage to each pedestal - which the RV owner is paying for- and not propose a rule that allows the site owner to supply power which is dangerous to the RV and it's equipment.
Keith
It has already passed, comments were reviewed. If you read the page on the link, all the rule changes favored the park owners with the exception that all new RV's be equipped with reverse polarity protectors. Also RV's can only have one power cable attached to the pedestal, not able to use a 30 and 20 any more. The 20 can be used for outside accessories though. These rules are updated every 3 years.
Just a question, no intention of starting a inverter/charger argument.
My Victron 3000 can "bump up" the output via the battery bank if a low voltage or dip in provided power is detected ( to about 60+ amps), Is this the same situation that the Hughes unit is being banned from doing, but in a different way?
No. This is a completely different technology. Your inverter draws power from
your battery bank to boost system voltage. It does
not affect the shore power supply grid in any way. Magnum has a similar design in its MSH3012M hybrid inverter.
Seems stupid to not allow Autoformers. The Hughes has separate windings in the can that are epoxied and switch windings depending on the input voltage. Or do nothing.
Their comment is trading amps for voltage makes the equipment hooked to the system more efficient causing lower run times and using less power in total.
Their proprietary design uses one amp at 50 amps full power.
I am sure there a cheaper less efficient ways to raise voltage. Probably are the culprit?
Boost transformer? Something about not separate windings can cause problems inside the transformer?
One summer at Liberty Harbor RV Park across from Statue of Liberty & World Trade Center location, campground voltage was too low to run our roof air conditioners. We planned on being there for two months, so our solution was to order Hughes AutoFormer, which boosted voltage so we could be comfortable.
We run a long 50-amp extension cable into our bay and plug the Autoformer into the extension. We have a short 50-amp 'shore cable' with a SmartPlug end that connects Autoformer outlet to coach 50-amp SmartPlug inlet. BTW, this extension idea would also be a great way to secure a portable EMS under/over voltage protector. Keeping these expensive items behind a locked bay door fully protects them from theft, rain & other weather issues.
I learned about the NFPA code from this thread, and found the code on the internet. For the life of me I do not know why NFPA would make the statement as Autoformer is not a safety issue. It seems that "the" wording may have been in the code for some time. Why do they care. Would be nice if the reason is given.
Autoformer increases voltage and will cause increased electric consumption, but never more than the pedestal circuit breaker. It never affects other campers more than running additional appliances would.
Low campground voltage will cause motors (induction load) to increase amps consumed, triggering increased motor winding heat. And if voltage is too low for too long, motor windings can be damaged. Too low voltage will not damage (resistive loads) light bulbs, heating devices like hair dryers, propane refrigerators.
We NEVER run roof air conditioners on low voltage. Although Autoformer can be plugged in all the time, ours is stored away when voltage is normal, which is 99% of the time.
We are planning to continue using our Hughes Autoformer when needed.
Here are a few old blogs on the topic:
http://www.rv.net/forum/index.cfm/fuseaction/thread/tid/28998339/print/true.cfm
http://www.rv.net/forum/index.cfm/fuseaction/thread/tid/26542310/print/true.cfm
I don't think it's completely fair to point a finger at the RV park owners. It's standard convention in electrical design to assume that only a percentage of connected load will be drawing full power, and that percentage is far less than 100. You can see the same fudge factor at work in a modern home with a 200 amp service and main breaker. Add up all the amperages of the individual breakers, totals way above 200, probably 400-600.. Now assume every house in a town with a 200 amp service actually starts using 200 amps.......every transformer fuse in town will blow.
The alternative is to wire for worst case scenarios and you would move from residential style wiring schemes to more of an industrial grade design. Cost? Astronomical.
There is a spot on the NFPA web site where you can look up why they did what they did on different code sections. I will try and find it.
I found it
The code
551.72(D)(E) Connected Devices.
The use of autotransformers shall not be permitted. The use of listed surge protective devices shall be
permitted.
Committee statement
The use of autotransformers places severe additional stress on the surrounding electrical
infrastructure not accounted for in the load calculations in this section. Park operators report that
low voltage conditions typically exist when surrounding sites use these add-on devices
14 members voted for and 1 against
Arocha, Jorge L.
No substantiation documents were provided and furhtermore, if the system is designed correctly, there should not
be a problem using these devices.
This is the reason the committee voted for this. Look who entered the public input.
Public Input No. 554-NFPA 70-2017 [Section No. 551.72]
Statement of Problem and Substantiation for Public Input
The use of Auto-transformers (or buck-boost) places a severe additional stress on the surrounding
electrical infrastructure not accounted for in the load calculations in this article. Park operators report that
low voltage conditions typically exist when surrounding sites use these add on devices
Submitter Information Verification
Submitter Full Name: Wade Elliott
Organization: Utility Services Group, Inc.
Affilliation: arvc
Street Address:
City:
State:
Zip:
Submittal Date: Mon Apr 17 15:14:30 EDT 2017
Attached is an Autotransformer wiring diagram:
Hughes Autoformer is an autotransformer with voltage sensing circuit that chooses different transformer connection-points based on how low the incoming voltage is.
Hughes documentation said fully automatic 10% boost when needed, which is from 95v to 115v.
We made the attached spreadsheet so I can determine when to use our Hughes Autoformer.
I hate autoformers, not because they don't work, but because they bring out the worst in human behaviors.
That "worst" being:
- The HAVES vs. the HAVE NOTS.
- Or, "I paid for 50 amps, so I don't care if you (as my fellow camper) don't have (useable) power. I'm going to take my 50 amps and to HELL with any common sense and the Golden Rule — Instead of helping you, as a fellow camper, in a poor power situation, I'm going to implement MY GOLDEN RULE: i.e. - I'm going to take advantage of you and make your life even more miserable in the process.
[/list]
I have absolutely no problem with the use of autoformers to safely run the bare minimum of appliances. But I have yet to see an autoformer application where the owner was able to curb his/her appetite/ego and stop there, at the bare minimum needed to get by. I explained all of this over nine years ago.
That thread contains not just the common sense details of why autoformers invite abuses, but also the detailed math and science behind why the NFPA (now, in 2017/2020) feels the need to implement rules outlawing autoformers in order to help curb the type of human behavior that cannot see beyond its own greed:
The typical thinking is if one air conditioner is good on an autoformer, then two AC's would be better and four would be ideal! I have seen it time and time again and it is based upon the lack of electrical system design understanding that Chuck Pearson speaks of: Just because you have a 30 amp or 50 amp breaker, or both, at each power pedestal in a park, it doesn't mean that the park is designed to simultaneously handle full rated output at every outlet. And it certainly doesn't account for why the park may be in a dire poor power situation.
If, for whatever reason, a park's system is stressed, there is no "free makeup of power" from any number of autoformers. There are only more overall power system losses and the autoformer owners being encouraged to use more power than they actually need to minimally get by, thus taking power away from those that do not have the wherewithal to transform their needed voltage and current.
Low Voltage and Appliance Performance - Page 2 (http://www.foreforums.com/index.php?topic=9844.msg44646#msg44646)
I didn't have much luck in terms of Forum members acknowledging that these abuses routinely occur (either through ignorance or malicious intent) nor much of any agreement that they now understood and would refrain from any further "Ugly American" behavior.
Thus, I just grit my teeth when this ignorance crops up again.
HTH (again),
Neal
That 9 year old thread you linked was very interesting! I hardly ever delve that far back in the archives. Great reading! :thumbsup:
But, in spite of your (clear as mud to me) technical explanation, I still believe autoformers are black magic...and as such should be shunned.
Interesting thread on this issue. The not damaging the appliances would seem to be the over riding reason to use an Autoformer.
Thirty two years ago we drove a 29' grand villa SBI to Indy for the race. Dry camped in the American legion halls parking lot across from the track. Minimal electricity.
A additional last person showed up in our group and we hooked them up to the limited 30 amp power leg we were all on.
Voltage dropped quite a bit. So we all turned on our refers to gas instead of AC.
The voltage came up a bit in response. We all made it though the race.
Most here who have installed residential refers have added enough solar panels to their coaches to offset the increased power draw they require so the power issues left are several,
All electric coaches. Long ago every coach had a propane stove top/oven.
Propane water heater.
No dark paint job, just white gelcoat.
One or Two 12 volt fan propane furnaces.
All of this to reduce the power needs as the gas generators were fuel guzzlers and noisy under your bed.
Only a few of us old die hards left.
I personally was trained long ago to not modify the coach to increase its power consumption.
So for me personally to install, an Autoformer to protect my coaches system from the low voltage maybe made worse by house refers, dark painted graphics, electric cooktops, two large tv's on all the time, internet hubs on 24/7, electric water heaters and such in my neighbors coaches seems only fair.
If everyone in a campground had the idea that power was of a limited nature and bought rigs built with that in mind things would be fine power wise.
Larger interior volume multi slide coaches with dark paint, house refers, electric cook tops, three airs to compensate have changed the industry.
Painted Dark ac covers. Goes on and on.
Good thoughts to those who have added large solar panels to help run their coaches systems.
But the 110 volt power requirements have obviously gone way up. And the higher temps we are seeing the last few years has increased a Park's energy load on top of larger more power consuming darkly painted coaches.
The original Foretravels could dry camp without gens running up to the mid to high 80's degrees without the gen or ac's running. Obviously humidity changes that quickly.
Power issues are enough for the park owners and the industry to ban Autoformers.
Will not work as was stated as everyone will simply build them in like we are doing. I have rarely needed to use it myself but more secure built in.
Me personally I do not feel any guilt doing so as we still have retained the white body shell, propane cook top and propane capable refer.
Kudos to those here whose solar can basically run their coaches except for roof airs and hot water and maybe stovetops.
But my old smaller interior non electric everything coach I would think consumes less power than the alternative designs.
Solar seems fairly dependable so the main loads are reduced.
Almost all the new coaches require a lot of power. Power everything. Bold dark paint.
!We have met the enemy and they are us" Pogo said seems to be true.
My Autoformer can be bypassed I understand if needed.
I can hear the coaches around me air's kick on fairly early in the day as their less insulated dark painted body shells get hot quickly.
Most current rv's were not made to reduce the power load. The opposite has happened.
Most owners would laugh if I mentioned the power their coach uses.
The old prevost bus guys 35 years ago ran ultra quiet Martin turbo diesel gen sets inside of a thickly insulated with sound absorbing foam compartment and standing next to their coaches you could barely tell the gen was on.
They left it running 24/7. They had to as the metal shell got hot or cold quickly.
Pardon my ramblings but as was posted our mutual greed has caused this to some extent.
Even total solar coaches are consuming power to run air's and a aquahot water heater and maybe a cooktop.
I took a minute last night to look into the Hughes Autoformer because the name troubled me. But according to Hughes' brief description their "autoformer" is a multiple tap isolation transformer and therefore a good thing, and not a single winding autotransformer, which can be a bad thing in the wrong hands.
As far as drawing too much power from the power pole, the circuit breakers will handle that automatically. If you do the math, low voltage at the power pole requires more current flow for the same amount of power.
To keep this simple and practical we can use the equations for DC power for a good enough answer.
Power, measured in Watts is simply Voltage multiplied by Amperage. For a certain amount of power, if one goes down the other goes up.
FWIW, back in the 1990s when the plant we worked in doubled in size Lynn successfully argued for an internal high voltage distribution network with local step down transformers. When I started working there, a path had been beaten into the roads running electric motors to the local re-winding shop. When I brought Lynn on board I asked Lynn why? We then went to the owners and let them know that Wright electric could rewind the motors from 230VAC to 208VAC. At no extra cost.
I would have been happy with some cookies and milk.
As I read through these comments, I sat here watching our incoming power. We are on 50 amp service here, but have seen the one leg go down as low as 111 and they both fluctuate all day long. As the heat rises here, so does the loss of power coming into the coach. No, we have had no problems yet, have not tripped a breaker, but we are only running 2 of our 3 airs and really just keeping the coach at a reasonable temp, since when you go outside, it hits you like a brick if you have it too cold in the coach. Besides, wife gets cold easily, so I man up and try to appease her! lol
In saying all of this, I can see both sides of this issue. Is the park owner correct in saying that is their only issue, Autoformer's or are they also masking the problem of wire runs in the park that are not up to snuff?
I do believe that if I am plugged into either 30 amp or 50 amp, if others around me are using a device that is helping them in their securing of more or steady power, then I will be the victim in the long run with low voltage.
Maybe this is how the NFPA decided on this rule, but also knows that not all RV parks are wired the same.
Just an observation on my part, since I don't have a Autoformer.
Give it a few years and they will be obsolete. As will our current generators.
https://www.youtube.com/watch?v=C_S7s6rGUwY
We have an autoformer as, until last year, the local navy base campground had abysmal power. It's since been upgraded. My wife has asthma and I a heart condition that precludes being in high temps for very long hence the need for adequate power for the A/C. I will continue using the unit as we are only using what we paid for and need. If someone has a large all electric coach and/or with three or four A/C units then it's up to the campground to refuse them service or upgrade their systems to accommodate them. So many campgrounds have not kept up with modern coaches and their power requirements but seem to be happy to raise prices for the same level of service.
There is no proper logic to this NFPA rule but I believe that they listened to one or two sources without understanding the "problem". Why they did not take into consideration the dangers of under voltage, especially older motors without overheat protection, is beyond me. Unusual for the NFPA which is a well respected institution.
Keith
There are a number of parks I have to pay extra to plug into the 50A outlet vs the 30A outlet.
Coaches now are using more power then before. Just like the size of the coaches are getting bigger.
If a park can not handle 50A load they should then remove the 50A plug & tell renters they only have 30A 120v power, or upgrade their system where it can handle the load. Autotransformers are a crutch that is used when a park does not have an acquit system to handle the load. If a park is complaining about autotransformers they then need to fix their power systems or stop renting sites.
If the park can't provide proper power that I paid for. Then I ask for a refund and move on. Hey, if they are going to be In the RV Park business then upgrade your years old system, instead of just raising you rates, and putting out a few picnic tables. That's the end of my rant. 😎😎👍
I see both sides but I will be installing my Hughes autoformer as soon as it gets here. I have already installed the watch dog. I have been beside many campers that leave their AC's running while they are away all day. (And no they didn't have pets) Have even had them ask me why we don't. I believe the comment was it's paid for why come back to hot RV. It may take awhile to cool back down when we return but I don't believe in wasting something simply because it doesn't cost me extra to use it. But we had a close call with bad power over the 4th caused by the neighbors RV. Power was fine until they plugged in, then I smelled electric smoke. John flipped the breaker and we started trouble shooting one leg was way high and the other way low. Even with everything off they were still dragging one leg down. When the owner moved them to another pole everything was fine again. They tried to say our RV was just too sensitive. I am not sure how they came up with that when they were getting shocked when they touched the outside wall of theirs. In any case I will not take the chance of frying my little darling when there is something we can do to protect her. We ordered the Hughes autoformer and the surge protector with emergency power off the next week. Mine will be in my electric bay out of sight out of mind.
We think leaving a Hughes Autoformer in the line all the time, risks having it fail over time from constant use. These are expensive and serve no purpose unless voltage is too low. Much more important to have a Progressive Industries EMS in use all the time.
If campground voltage is below 100 volts, Autoformer boosted output will likely still be too low for roof air and other motors (elec fridg, etc). Autoformer is not a fix-all. It is tool that needs to be managed.
If the Hughes EPO model with disconnect is hard wired into the system, there was no way to "bypass" like Progressive Industries hardwired and portable EMS offer.
Power is power, and once the parks distribution system is overloaded and voltage starts dropping an autotransformer is just your personal band aid, given that enough users also have an autotransformer the park voltage drops even more until smoke starts appearing and breakers pop. The lucky campers are the ones closest to the parks main feed.
Barry not so.
I just picked up our coach today and the Autoformer is in the cord reel bay behind our Glendinning cord reel.
My buddy has installed the hose reel sideways in our compartment. The spot for the Hughes unit was behind the hose reels take up bin. The Autoformers indicator light are not visible as the face the tank but the plug faces outward and my buddy mounted the disconnect box female receptacle on the left compartment wall.
If the Hughes failed I can reach in and unplug it from the system and plug the shoreline reels 50 amp plug directly into the coach.
Same time he installed a progressive 50 amp guard unit on the coach side of a new transfer switch. If the gen fails or anything goes wrong the progressive unit will interrupt the power. With the unit is a small remote panel from progressive that has a bypass switch on its face. If it fails flipping the switch bypasses it.
I am keeping the external progressive unit as if the built in fails I have a shoreline backup.
The installed one covers the output from the ATS to the coach. An external one only covers the shoreline.
I Remember posts here saying they had wired their progressives this way. Thanks.
That combined with my blue sea M2 indicator panel installed where the powerwatch and the lower meter were before just about finishes the electric work for a while.
The gendinning is a marine unit with no slip rings. Shore wire coils in a drum.
Nice setup for an old roach coach.
Thanks Turbo, for clarifying why the code entry was made. Found the "you cannot" on a 2011 document, so wonder if it has been around for a while.
The Auto in Autotransfer does not refer to an automatic voltage control:
An autotransformer is an electrical transformer with only one winding. The "auto" (Greek for "self") prefix refers to the single coil acting alone, not to any kind of automatic mechanism.
An autotransformer has a single winding with two end terminals, and one or more terminals at intermediate tap points. It is a transformer in which the primary and secondary coils have part of their turns in common. The primary voltage is applied across two of the terminals, and the secondary voltage taken from two terminals, almost always having one terminal in common with the primary voltage.
In an autotransformer part of the current flows directly from the input to the output, and only part is transferred inductively, allowing a smaller, lighter, cheaper core to be used as well as requiring only a single winding.
Limitations:
An autotransformer does not provide electrical isolation between its windings as an ordinary transformer does; if the neutral side of the input is not at ground voltage, the neutral side of the output will not be either. A failure of the isolation of the windings of an autotransformer can result in full input voltage applied to the output.
Autoformers = waste of money
"Progressive Industries EMS in use all the time" = Smart.
If the RV park do not have good and safe electric then why stay there, what if the RV next to you catches on fire, hopefully you are not out to lunch while your RV is safe with Autoformer >:D
Thinking you know a good campground in Texas where low voltage is not a problem? ;) ;) ;) ;)
One amp at 50 amps actual power consumption to almost never have a voltage issue again and as others have done here to have a fairly hard to fail system with a progressive industries fault controller on the main line for the coach.
After shore or gen. Autoformer on the shoreline in,
Wishful thinking: The rise and fall of Erwin Hymer Group North America | TheRecord.com (https://www.therecord.com/news-story/9491493-the-rise-and-fall-of-erwin-hymer-group-north-america/)
Hopefully someone took over the fuel cell R&D portion of the auction. It has already passed.