complaints when using a hughes autoformer

dockmasterdave wrote:
Old Biscuit I only have the PI surge protector, not EMS. Yes, I would like to buy one but can't afford everything at once.
So my surge protector won't be correcting before the hughes, just protecting it.
This deal just showed up for a good condition Hughes 30 amp for $120.
Possibly too good to pass up. I can still buy the good PI ems later and put it inline after the Hughes as you suggest.

That's exactly the way I have mine....surge only in front of the Autoformer and EMS after. Everything connected with plugs/receptacles so removing a unit in the event of failure is just a matter of unplugging.
I have had the autoformer for about 15 years. I bought it after a trip to the northeast and having to move out of a few older campgrounds due to low voltage when people were running their AC's . My autoformer is in a bay so it's protected from elements and prying eyes.

dockmasterdave wrote:
I am looking at a used hughes autoformer. I know some parks rules say they are not allowed.
Some parks we have been in, I have seen voltage at @ 102 to 104 with my a/c on.
I would be using a PI 3o amp surge protector in front of a hughes autoformer then the rv cord.
I just wondered if anyone has gotten in trouble for using their autoformer ?

Good idea to test it. I have had a 50 amp autoformer for a long time, it suddenly started boosting voltage to 135 VAC. Hughes rebuilt it and all is back to normal but the rebuild is not cheap. The shipping of those heavy things is also not cheap.

I took it to Quartzsite where Hughes had a sales booth and they took it with them thus saving me one way shipping.

jplante4 wrote:

Ralph Cramden wrote:

GordonThree wrote:


Report this park to the County building inspector, and the state building inspector. Low voltage is a safety issue.

Absolutely.....did so in 2008, and twice since as recent as last season. System has not been touched.

I dunno Ralph. If you've been there to a park with this problem a number of times in the past 10 years, I think some of that may be on you.

Funny I just had to get out my autoformer at a park over the weekend, that is notorious for low voltage. It is a decent park otherwise. This park is on of the reasons I purchased a autoformer.
I can ruin my equipment waiting for the park to upgrade their system or I can address the low voltage issue myself.
I have to laugh at those who somehow think the autoformer is making things worse. The park had a low voltage problem when I arrived, It had a low voltage problem while I was there plugged in via my autoformer, and it had the same low voltage problem when I left.
The problem will remain until the CG address the root of the issue.
Until then I will keep auto forming!

Lantley wrote:
Funny I just had to get out my autoformer at a park over the weekend, that is notorious for low voltage. It is a decent park otherwise. This park is on of the reasons I purchased a autoformer.

Even well run, well funded park systems with up-to-date electrical facilities such as our Ontario Provincial Parks can be stressed during the busy summer months to the point where low voltage becomes a real issue. It's happened to us each year at The Pinery which has a 1000 sites in operation, about 40% of which are 30 amp electrical. During July especially it's tough to get a site of any kind without reserving well in advance, an electric site is almost impossible. At those times when everyone is running A/C voltage takes a nosedive and every summer my Progressive EMS says enough is enough and disconnects. A voltage regulator like the Hughes Autoformer would solve this but at something like $800+ Cdn it's pretty hard to justify when this only happens 2 or 3 times a season. Disconnecting with my EMS isn't the end of the world as the trailer just continues to run on propane & battery power - we just can't run the A/C but we use it so seldom anyway losing shore power for a few hours just hasn't proven to be the issue for us that it would be who is a full timer or lives seasonally in their camper.

A simple/short answer (sorry!). :R

The way an autoformer works is simple: power in = power out, minus autoformer internal losses. If voltage is down on the input side and voltage is up on the output side, the current on the input side HAS TO go up. Example - if voltage is boosted by 10% on the output, current draw on the input side will go up by 10%. An autoformer can't make power but it can lose a bit.

You are limited to the 30 amps at the pedestal (or 50 amps) and the breakers do not care what the voltage is. So say a 30 amp pedestal was at 100 volts, the most you can draw is 3,000 watts (down from 3600 @ 120 volts). The autoformer will be boosting the output by 10% to 110 volts but will only be able to draw max 27 amps inside the RV (not really a big deal). When an autoformer is in boost mode, you lose available capacity compared to being at 120 volts.

If you had to, I would argue with a CG that if the voltage is low, you draw less power compared to being at the normal 120 volt level so what's the problem... Have fun with that.

Voltage drop in CGs is due either to the NEC min. code requirements that were used at the time of construction or inadequate maintenance of CG wiring. It's usually the former, and older CGs are just not able to keep up with the high demands of today's RVs. Newer campgrounds are wired with loop-fed pedestals with up to 9 sites on a 200 amp feeder and are MUCH less likely to have voltage issues. Older CGs had remote panels around the property often with individual 30 amp (or 50 amp) runs to sites from a remote panel. You may be connected to a #10 wiring run to your site or be on a 200 amp run shared by other users.

In CGS that are predominantly 30 amp pedestals, many 50 amp RVs are often plugged into them and draw more load than the CG would have been designed for. Prior to 2005, only 5% of CGs had to have 50 amp pedestals, after 2005 it was changed to 20% being required. In the 2017 edition of the NEC, CGs are now required to have 40% 50 amp pedestals. This is a HUGE change from prior to 2005. Good luck on finding newly built CGs anywhere. Some owners will have voluntarily built above min. code requirements.

Another thing that comes into play is the demand calculation requirements of the NEC. One 30 amp pedestal has a demand load of 3600 watts and a 50 amp, 9600 watts (now increased to 12,000 in the 2017 NEC). One site only is calculated at 100% and the more sites there are, the lower the demand figure is up to 36 sites or more which is down to 41% total overall. So there could be a case where many newer higher demand RVs using 50/30 adapters are pushing the main service and sub-feeders to the max in an older CG

So, if a CG is maxed out on "normal" demand loads on a busy & hot summer day, the demand at the main service point or a feeder to a CG section could be near it's limit already. Theoretically, if enough sites were using autoformers, a section or entire CG could be taken down. We were in a CG once that was in that predicament and asked everyone to minimize their electrical usage, despite being very hot out. In reality though, I don't think there are really that many autoformers being used. I've only ever seen a small handful of them in our travels.

We bought a used 30 amp Hughes autoformer a few seasons ago for just over $200US after being in a few too many CGs with low voltage. One was so bad, as soon as we plugged into the 30 amp pedestal, our EMS tripped because the voltage went below 104 volts before even turning anything on. If you value voltage sensitive electrical things in your RV you can either find a better site in the CG with good voltage, find another CG or pull out your autoformer. I'd opt for an autoformer every time. If staying in an older CG especially, you can easily have low voltage. It's not a rare occurrence out there. In the beginning I was not in favor of autoformers but now have no problem with them.

I made a 6' extension cord for the autoformer so I can put it under our TT rather than have it sitting at the pedestal.

I have heard of CGs banning the use of autoformers but have never run across one. Have also heard of some CGs banning electric heaters which I don't understand because they don't restrict the use of AC units. I think some CGs have no clue about electrical stuff. Why frown on autoformers and not limit how much electrical things people use in their RVs? We rarely go over 15 amps and can't see another 10% draw from the autoformer causing anyone a problem.

Lastly, the output of resistive appliances (toasters, coffee makers, space heaters, etc.) varies as the square of the voltage. If at 100 volts for ex., the output would be .9 x .9 = 81% of the rating at the nominal 120 volts. It can take longer for toast & coffee and you may not be warm enough inside. One more reason to have good voltage.

myredracer wrote:
When an autoformer is in boost mode, you lose available capacity compared to being at 120 volts.

Although I may be plugged into a 30 amp campsite supply my normal draw is but a few amps, enough to keep the fridge running, the converter idling, etc, and it's only when we may briefly run the toaster or coffee maker would that draw increase ... but only for a few minutes and still only adding ~ 6 amps to the draw. Only those few times each season we may run the A/C for a few hours would we draw an additional 14 amps but in those cases, because we always practice power management and would turn off the A/C compressor for a few minutes while using another high draw device such as my wife's hair dryer or the toaster or coffee maker, our total draw is always still within 20 amps max. I can't think of any time we've pulled more than that so any loss in capacity due to autoformer use would be a moot point for us ... and moot for anyone else who gives this any thought. :R

myredracer wrote:
If you had to, I would argue with a CG that if the voltage is low, you draw less power compared to being at the normal 120 volt level so what's the problem... Have fun with that.

Too funny. :B You just made me spit out my tea. :W

myredracer wrote:
In reality though, I don't think there are really that many autoformers being used. I've only ever seen a small handful of them in our travels.

A "handful" I'd bet would even be an overestimation, more like hardly any at all.

myredracer wrote:
Have also heard of some CGs banning electric heaters which I don't understand because they don't restrict the use of AC units.

I've never seen this here in Ontario but we have run into several campgrounds in the US where we've been advised when checking in to let them know if we intend to use either an electric heater or A/C and pay an additional fee for doing so. :(

myredracer wrote:
Have also heard of some CGs banning electric heaters which I don't understand because they don't restrict the use of AC units.

Campground would prefer to sell you propane for the furnace than give free electric.
And of course with anything free people over do it so the maintenance guy has to deal with overloaded RVs and the pedestals tripping.

BTW last Summer I was at a Montana campground with BRAND NEW 30 amp electric and less than 95 volts during the afternoon heat wave (almost 100F). Even my Franks booster was cutting out. Have since adjusted the cut out down to 80 volts and will let the PI-EMS decide when too low to boost is reached.

myredracer wrote:
Have also heard of some CGs banning electric heaters which I don't understand because they don't restrict the use of AC units.

AC uses less power. It takes more power to bring a space up 30 degrees than down 20.

Gil,
Could you give us a good estimate of power usage between an AC laboring on 100 volts, and an AC operating more efficiently on 110 volts boosted by an autoformer? Of course the one on low voltage may well burn up.

I don't use an autoformer, nor have I run across a park to date where I needed one, but in those that prohibit them in their rules, I've found the predominate reasons are that they believe the devices somehow "steal" power, although I've never found a park manager or owner that could logically explain how that happens. The other reason has been possible liability insurance issues because the NEC prohibits the use of auto(trans)formers in RV's, which it does. I have inquired of the NFPA what the reasoning is behind the prohibition a couple of times, but I've never gotten a response.