Hughes Autoformer RV220-50SP Testimonial

[Victory Blue]

Originally Posted by Johnontheroad

Just curious... I’ve always thought that you get nothing for free, so where does the autoformer get its extra power? If memory is correct, I was at park where these devices were forbidden because if the autoformer boosts voltage for you, then others on the same circuit have less.

The theory was that if voltage was on the low side but above minimum (say 106V) then the boost provided by the autoformer would lower everyone else’s voltage. In those cases, using the autoformer may make your neighbors power drop below the proper minimum, for this example 103V.

Anyone have a better explanation of where the extra power comes from?

That’s one of the myths that surround the Autoformer. The voltage is boosted by the Autoformer using a small amount of current (amps) to boost the voltage, not by lowering other CG user’s voltage. The higher voltage then lowers the amps drawn by downstream devices. The breaker at the pedestal will still trip at about 45 amps (or less) continuous draw on one leg so it’s not possible to draw more current than you’re paying for or to draw current from someone else.

I’ve also had campground personnel, where I’m hooked into 50 amp service, tell me the reason my voltage is low is because I have 3 air conditioners; usually my ACs aren’t even turned on yet. I try to tactfully explain that as long as I’m not tripping the breaker I’m not drawing more current than I’m paying for and I’m not causing the low voltage at the pedestal.

BTW, the existence of these nonsensical myths is a good reason to install the Autoformer inside and out of sight.

This is from the Hughes website:

“Autoformers are used in industries to stabilize voltage and lower the operating cost of equipment. The Autoformer has 5 windings: 2 primary and 3 secondary. All models have surge and spike protection. When the unit is in Automatic and the park or input voltage is 116 volts or below, the output is 10% over the input. When the input is over 118 volts, the output is 2% over the input.

The Autoformer DOES NOT take power from the park.

It does not affect the park or input voltage, or make electricity.

What it is doing is changing the voltage – amperage relationship, lowering the amperage and raising the voltage. Since appliances run better on higher voltage, lower amperage, less overall power is used from the park, and better service is enjoyed from your RV

An Autoformer running at full output (50amps) will use 1 amp, but will cause appliances to cycle more often and run cooler. This will use less total power from the park.”

[KanzKran]

Originally Posted by Johnontheroad

Just curious... I’ve always thought that you get nothing for free, so where does the autoformer get its extra power? If memory is correct, I was at park where these devices were forbidden because if the autoformer boosts voltage for you, then others on the same circuit have less.

The theory was that if voltage was on the low side but above minimum (say 106V) then the boost provided by the autoformer would lower everyone else’s voltage. In those cases, using the autoformer may make your neighbors power drop below the proper minimum, for this example 103V.

Anyone have a better explanation of where the extra power comes from?

That’s a loaded question. In short, it doesn’t get extra power. Not with inductive loads like motors, at least.

Induction motors with fixed loads turn at essentially constant speed and draw essentially constant power (torque x speed = constant). From Power = volts x current*, with constant power load at the shaft like the A/C compressor and fans, if you lower the voltage, the current will necessarily rise. When voltage at the pedestal droops with heavy electric use in the park from all those A/C units, the current draw on each unit goes up roughly in inverse proportion to the voltage reduction.

The higher current in the motors results in additional heating in the motor windings and as a result, they run hotter (winding resistance). Winding insulation life (statistically speaking, of course) decreases by half for every 10 deg. C increase in winding temperature, so running at low voltage with higher current draw will reduce the anticipated life in hours of that motor. So generally speaking, it’s better to operate a motor close to its design voltage, which in North America is 115V on a 120V system (or 230V on 240V, or 460V on 480V, and 200V on a 208V system).
They will operate well over a range of voltage of course, but they’re actually designed and the various performance specs are based on that design voltage.

The Autoformer will boost the voltage at the motor, which results in the motor drawing less current for the same fixed load. So at the pedestal, sagging voltage causes an increase in current draw with or without the Autoformer boosting the voltage, but at the load, the voltage is 10% higher and the current is reduced in an inverse relationship (1/1.1). The power from the pedestal is still roughly the same since the connected load is still the same, but with reduced voltage at the pedestal there is increased current through the pedestal. With or without the Autoformer.

There is a little bit of extra energy used in the Autoformer, since it’s not 100% efficient (no transformer is), and that’s why it gets warm. But it’s small.

One argument against them is that with droopy voltage, you won’t be able to run as many A/C units simultaneously without tripping your own coach’s breaker, or the park’s, so you’ll load the system a bit less, minimizing the total current load on the already overloaded park’s system, and by extension, not cause even more voltage sag on their system. But that’s only because you’re not running certain equipment, thereby keeping your total energy usage rate lower than if there was no voltage problem.

On the other hand, with purely resistive loads like water heater elements and electric space heaters, coffee machine, hair dryers, and so on, sagging voltage at the load will result in a reduction in energy use. Like dimming incandescent light bulbs - they get dimmer as the voltage drops. Same with heating elements.

If the voltage is droopy and you boost it with an Autoformer, a resistive load will draw more current, all the way through the power pedestal. So in that case, using an Autoformer will actually increase the current draw at the pedestal. But not more than what the load is designed to draw, as long as the voltage isn’t more than what it’s designed for (typically 120V in North America).

So in short, for motor loads, the Autoformer won’t result in a higher current draw from the pedestal than if it wasn’t there, but it’s better for your motor loads as the voltage at the motor is boosted to a value much closer to design value, and the current draw on the coach’s feeder and distribution system is reduced, back as far as the boost transformer. There will be a higher current draw from the pedestal under low voltage conditions whether you use the Autoformer or not.

For resistive loads, the Autoformer will result in higher current draw from the pedestal under low voltage conditions, but it will not result in higher current draw than what the load was designed to draw, assuming the voltage is not boosted higher than 120V, the design voltage of the load.

I suspect many park operators don’t understand how these boost transformers actually work, though as I mentioned before, it’s possible that boosting the voltage at the coach in hot weather allows the camper to use more air conditioning than without it. Whether disallowing that is fair to the camper is another thing.

*ignoring power factor (pf) and efficiency (eff) for the sake of illustration, and because it unnecessarily complicates things for relatively small net effect.

Edit: I type too slow ha ha.

[Victory Blue]

Thank you, Kanzkran. Much better explanation than mine.

[LWBAZ]

Originally Posted by Victory Blue

BTW, the existence of these nonsensical myths is a good reason to install the Autoformer inside and out of sight.

Not to mention making it less likely that a fellow camper will borrow it from you.

And forget to return it...

[MRUSA14]

Originally Posted by LWBAZ

Yep, I saw that Marc, but several people have reported placing an online order and getting the discount.

Non-issue for me at this point, but if it helps others that's great.

You are right! I just placed the order and was given the 15% discount despite the fact that the website says it's not applicable. Thanks Bigrig2 and LWBAZ !

[DebbieMH]

Originally Posted by Victory Blue

Lynn,

I can’t speak for others but we already had the Progressive hardwired in when we got the Autoformer.

The Autoformer is doing more than low voltage protection, the Progressive does that. But, Progressive’s protection is to turn off the power when the voltage drops too low. Instead of turning off the power the Autoformer boosts the voltage back into an acceptable range.

Higher voltage, even voltage that just stays around 120, is better for electrical devices like AC units since, as the voltage to them drops, they draw more current. In general, more current means devices run hotter which shortens life.

Thanks! Great explanation

[docj]

One thing that hasn't been mentioned in this thread is that the Progressive unit has a feature that neither Hughes nor Surgeuard offers which is the display of the "previous error" (PE) condition. This is essential to debugging intermittent phenomena such as can be caused by loose and/or corroding connections.

We had such a situation occur last year. My Surgeguard kept cutting off power and restoring it but there was no error code illuminated once the power was back on. I replaced the Sureguard with a Progressive and it immediately exhibited the same on/off behavior but it was capable of displaying that the PE state was high voltage.

A power company technician measured a steady state voltage difference of 3V between he two legs which he attributed to a loose connection somewhere in the circuit. Sure enough, after he tightened every connection in the pedestal and back to the distribution transformer the problem went away.

I'm not saying that this will every happen to one of you, but I like the added capability provided by that "previous error" capability. I'll stick with my Progressive and my old autotransformer.

[azbuzzard]

SO how are you getting the 15% off. When I go to the web site it just
states $529.97

[LWBAZ]

Don, below is an image of the web page that should come up when you locate the product on the Camping World web site.

Look at the top of the image, toward the right side, and you should see "15% Off Your Online Order- No Minimum / Use Code SPLASH15". Try that and see if it works.

[azbuzzard]

thanks Larry

[Johnontheroad]

The Hughes Autoformer (HAF) is a simple device, just a transformer that uses Ohms law to boost secondary coil winding voltage by 10%. It does so by using additional Amps - again, a simple Ohms law. So if you were drawing 30A at 106V you would now draw 33A to produce 116V (approx... there are parasitic loads, winding loss and so on in real life).

Note this only happens below 116V by Hughes design. The only reason to have less than the US standard voltage of 120V is that the power on the circuit you are plugged in the power draw is too high, like when you have too many AC units on one circuit. So when the HAF kicks in it actually reduces the input voltage of the device, and lowers voltage on the circuit it is on.

If you read the Hughes web site it tells you all about why you’d don’t want low voltage, and they’re right. But in a small note it tells you it gets the boost from converting Amps to more voltage.

So if you are at a camp ground with low voltage and turn on the HAF you are actually making the matter worse for your neighbors. This is why many campgrounds don’t want HAF devices used in their parks. With the continually improving power grid this really doesn’t come up as much as it used to, except in older parks or some of the newer ones in remote locations.

I’ve never bought an HAF because I just don’t feel it is right to boost my power at the expense of my neighbors. But that’s just me.

[docj]

Originally Posted by Johnontheroad

I’ve never bought an HAF because I just don’t feel it is right to boost my power at the expense of my neighbors. But that’s just me.

Regardless of whether the HAF is increasing your own current draw, it still can't let you exceed the breaker rating of the pedestal. So, if you are on a 30A pedestal you still can't exceed 30A. I'm not sure how that can be viewed as causing a problem for your neighbors. All you're doing is getting the power you paid for.

Joel (AKA docj)

[twinboat]

Originally Posted by Johnontheroad

The Hughes Autoformer (HAF) is a simple device, just a transformer that uses Ohms law to boost secondary coil winding voltage by 10%. It does so by using additional Amps - again, a simple Ohms law. So if you were drawing 30A at 106V you would now draw 33A to produce 116V (approx... there are parasitic loads, winding loss and so on in real life).

Note this only happens below 116V by Hughes design. The only reason to have less than the US standard voltage of 120V is that the power on the circuit you are plugged in the power draw is too high, like when you have too many AC units on one circuit. So when the HAF kicks in it actually reduces the input voltage of the device, and lowers voltage on the circuit it is on.

If you read the Hughes web site it tells you all about why you’d don’t want low voltage, and they’re right. But in a small note it tells you it gets the boost from converting Amps to more voltage.

So if you are at a camp ground with low voltage and turn on the HAF you are actually making the matter worse for your neighbors. This is why many campgrounds don’t want HAF devices used in their parks. With the continually improving power grid this really doesn’t come up as much as it used to, except in older parks or some of the newer ones in remote locations.

I’ve never bought an HAF because I just don’t feel it is right to boost my power at the expense of my neighbors. But that’s just me.

In a 30 amp system, you can't draw 33 amps at 116 volts, the breaker would trip.

With the boost, and running what you had been, your amp draw would drop 10%, from 30 amps at 106 volts, to 27 amps at 116 volts.
In that senerio you will not tax the campground system any more then you had before.

The problem is that NOW you have 3 more amps avalable. If you turn something else on, to use that new found amperage, then your using more power from the camp ground then if you were not using the boost.

So, as Autoformer states, adding the boost doesn't draw more power BUT it does give you the potential to, once on line.

Originally Posted by Johnontheroad

The Hughes Autoformer (HAF) is a simple device, just a transformer that uses Ohms law to boost secondary coil winding voltage by 10%. It does so by using additional Amps - again, a simple Ohms law. So if you were drawing 30A at 106V you would now draw 33A to produce 116V (approx... there are parasitic loads, winding loss and so on in real life).

Note this only happens below 116V by Hughes design. The only reason to have less than the US standard voltage of 120V is that the power on the circuit you are plugged in the power draw is too high, like when you have too many AC units on one circuit. So when the HAF kicks in it actually reduces the input voltage of the device, and lowers voltage on the circuit it is on.

If you read the Hughes web site it tells you all about why you’d don’t want low voltage, and they’re right. But in a small note it tells you it gets the boost from converting Amps to more voltage.

So if you are at a camp ground with low voltage and turn on the HAF you are actually making the matter worse for your neighbors. This is why many campgrounds don’t want HAF devices used in their parks. With the continually improving power grid this really doesn’t come up as much as it used to, except in older parks or some of the newer ones in remote locations.

I’ve never bought an HAF because I just don’t feel it is right to boost my power at the expense of my neighbors. But that’s just me.

[KiteSquid]

I want one