Surge Protection or Electrical system Protection

[ependydad]

X3, I would have preferred the autoformer. I had a hard enough time spending the money on the PI.

[wrapperman]

The biggest issue with the Franks Autotransformer is it robs Peter to pay Paul affect. You may be okay but your neighbors are paying the price. It robs them of amperage and voltage and makes their power issues worse.


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[Herk7769]

Originally Posted by wrapperman

The biggest issue with the Franks Autotransformer is it robs Peter to pay Paul affect. You may be okay but your neighbors are paying the price. It robs them of amperage and voltage and makes their power issues worse.

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I am not an Electrical Engineer (but did Minor in Physics), but I do know that the pedestal is fused at 30 amps and I can never pull more power than that without tripping the circuit breaker.

What comes into the autotransformer is whatever voltage is available at 30 amps draw maximum.

What the autotransformer does is take some of that 30 amps (about an amp at full boost; leaving 29 amps available to the camper) and convert it to voltage to boost the voltage delivered to the camper. So if you are "stealing" from anyone you are stealing from yourself.

Because you are paying for 30 amp service you are "taking" nothing away from your neighbors and you are only helping yourself.

While you may have less available amperage, your inductive equipment (Air Conditioner and Microwave) needs less amperage to run than trying to operate it at the lower voltage. (Watts=Volts times Amps with Watts fixed in an inductive circuit)

Example: A 12 RA (running amp) at 120 volt air conditioner needs 1440 Watts to run with 120 volts supplied. Since that 1440 Watts is a fixed number in an inductive load; if the voltage drops to 100 volts, the RA increases to 14.4 amps. This can trip the internal thermal protection in the compressor or eventually burn up the compressor motor. We won't even BEGIN to talk about the momentary start up amps required as even at 120 volts that number can exceed 25 amps for a few seconds (not enough; long enough; to trip the air conditioner's 20 amp breaker).

There is benefit to your resistive loads as well (like your water heater as an example). Since the resistance is fixed in a resistive load circuit, the power of the circuit varies by the voltage available.

For example, water heater element with 10 ohms of resistance at 120 volts will use 12 amps (1440 Watts). If the incoming voltage drops to 100 it will drop the amperage used to 10 (1000 Watts effective heating). (V/R=I then P=V*I)

This means your water heater has to stay ON longer to heat the water to the shutoff temperature.

[wrapperman]

I understand it may not be a big issue most of the time but does make a difference.
Here is an interesting article.
http://www.damouth.org/RVStuff/Autoform.shtml
I hope the link works.


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[Herk7769]

Originally Posted by wrapperman

I understand it may not be a big issue most of the time but does make a difference.
Here is an interesting article.
Autotransformer Use: "Stealing Power?"
I hope the link works.


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This is a Blog.

This quote says it all [B]"Stealing" may not be the right word.[/B]

Not only that but he makes a string of bogus assumptions:

"I'll assume that the main feed is always at 120vac, but that the long power wires shared by these two remote sites have a resistance of 0.25 ohms (not unlikely - that's only 200 feet of #8 cable).

Further assume that both of you are using exactly the same appliances which would add up to each of you drawing 25 amps if the voltage remained at 120 volts."

In fact he further decays into nonsense with "But the voltage won't remain at 120 volts (because of the resistance in the long power feed). Under these conditions, the voltage at each site will be 108.68 volts and each site will be drawing 22.64 amps."

This would not occur since the voltage drop would be less at the first campsite and get worse as you go along the circuit run due to the increased resistance in the aluminum wire length to the source.

Voltage at your site could be radically different than your neighbor down the row based on the distance between sites and the supply transformer.

It gets even more bizarre when he postulates that by using less than the 30 amps at your site, it is somehow your fault that the campground's wiring can't handle the load they advertise.

He also talks about running his AC at 98 volts for days. What hooey. My AC just grunts at 90 volts and won't turn over.

I believe he just does not want to spend the money to buy one and trash talks folks who care about their equipment and do own one.

[wrapperman]

With all due respect, in your reply are you assuming that there would be adequate amperage to make up the lower voltage, if so then autotransformers would be okay? But when power companies create brownouts, so they can manage power requirements, it gives campgrounds lower voltage which in turn feeds all transformer in the park lower voltage, which then makes the transformers output lower voltage.
The issue I have with autotransformers is when there is a limited amount of power, such as in a brownout. The autotransformers will give the owners of them adequate power (watts) by consuming enough amps. During a brownout a circuit only has limited amount of power and it must be divided equally among all users.
If a branch has 10 users and each one uses 3,600 watts (120 volts and 30 amps) then the total would be 36,000 watts. In a brownout the branch will drop in voltage meaning the total power (watts) will drop. If the total power drops to 30,000 watts for the branch (100 volts x 30 amps) then each site would only have 3,000 watts each. When a person has an autotransformers then they will indeed get 3,600 watts but will leave the other 9 sites 26,400 watts or 2,933 watts each and with the increased load of the autotransformer it will bring the voltage down further complicating the problem. Now if 2 people have autotransformers then the people with them will each consume 3,600 (7,200 watts) and each of the 8 others would now share 22,800 watts or 2,850 watts each. (Actually lower because of the new load on the branch). Now when each person that doesn't have a transformer their amperage increases because of lower voltage causing even more voltage drop. Now when the voltage drops, it causes the autotransformers to draw more power complicating the scenario even further.
I believe there is a misconception with autotransformers for the fact when there is a brownout the people that have them will let everyone else know how they didn't have any trouble running induction appliances. The ones without them have issues, which may imply they would work for all. If everyone had them then no one would have power. A brownout is when a power company limits wattages to certain areas. There is no way around making everyone have equal wattage in a brownout.

Now if the issue with a brownout is the campground fault then they do need to correct that, but when it is a power companies fault it would not be good for me because my PI would just turn my power off. Though, the people with the autotransformers would always be able to meet their power requirements.

This may be why campgrounds don't like them.

Or am I missing something?

[Herk7769]

Originally Posted by wrapperman

The autotransformers will give the owners of them adequate power (watts) by consuming enough amps. During a brownout a circuit only has limited amount of power and it must be divided equally among all users.

Watts will always be the same. Slightly lower voltage is compensated for by slightly higher amperage.

Since campground circuit protection is controlled by amperage detecting devices (circuit breakers) and not wattage detectors, low voltage can ruin your camper's inductive motors and electronics before any breaker lets go.

If there is too much amperage (at whatever voltage) being drawn the circuit will go down.

As to the statement regarding every camper using "the same amperage" is just bogus on its face. Many in this situation will still try to heat their water and fridge "with the campground's power" regardless of the brownout.

If the autotransformer is in boost, my fridge and water heater are on propane and I will bet I am using less amps than my "fellow campers."
I do not believe in "sharing the pain" when I have a way to protect myself.

[wrapperman]

Though doesn't it hold true when voltage goes down amperage goes up? The transformer for any given branch can only put out so many amps and when that is exceeded voltage drops.
When the power company (this is what I am referring to) cuts voltage an autotransformer will then increase its amps input to raise its voltage output. On any given day this power issue would not be a problem, it is when the power companies lower the voltage to meet demand.
One RV on an autotransformer (on any given branch) is okay but if everyone thinks that having an autotransformer (on any given branch) will solve low voltage issues, then that would not hold true. This may be why campgrounds frown upon them. Though your sites 30 amp breaker may not trip to many on a branch will trip the main transformer circuit breaker.

Thanks for the replay cause this subject is very interesting to me. I have always been curious to all of the comments made on electricity whether it be 12, 24, 120, 240 or whatever power it may be.

I am no expert on this subject but enjoy learning.

Putting all this aside I hope you are enjoying RVing season. Do y'all travel or mainly stay at a few locations? Do you attend Goshen's rally. I hear they are already booked solid. That's too bad cause my DW and I were trying to make it this year.
I hope our travels cross paths in the future.
Sincerely,
Bob

[fr1rd831]

I recently experienced low voltage incident at an rv park. First day was fine but the second day my progressive electrical system protection disconnected our power whenever my wife turned on the coffee maker. I checked the progressive unit and it read 107 volts. Was an issue the rest of the trip. We couldn't run the microwave and watch TV. So I just ordered a Hughes autoformer to have on hand for the next trip. We are going on an 8k miles, 3week road trip and last think I want is to have power issues if I can help it.

[wrapperman]

At one time I thought about buying one but I have never had an issue with brownouts and if I do I will just run the generator till power is restored to where it needs to be.
I have too many other items to buy and my DW says I only have so much money to spend a month.

[Herk7769]

The season has not started for us and will be delayed several more weeks. Spent the day yesterday and will spend most of today at the Kidney center with the DW.

So to try continue to try to explain what is going on,

Voltage is "pressure" being exerted on the electrons (water in our analogy) at the "beginning" of a pipe. It is the "upper limit" of how high the supplied voltage will be. It can never go higher (unless the pressure being supplied by the campground's transformer or the electric company is increased).

So the voltage "pressure" AT the beginning of the pipe that goes to all the camper pedestals on the circuit you are on will not change until someone connects and creates a PATH back to the Neutral buss at the source.

Now picture the "pipe" as a hose that can be stretched from a larger diameter to a smaller one by pulling on the far end. That results in a "tapered" hose that is larger at the source end and smaller at the most distant end. That taper is the effect of the resistance to water flow in the metal of the wire. The more conductive the wire, the less "taper" you get from the same length. The hotter it is outside the more taper the same material of the same length gets (more resistance for the same wire material as temperature increases). Copper feed wires are not effected near as much as aluminum feed wires (1/2 the resistance per foot as aluminum and much less effected by heat) but Aluminum feed wires are 10 times cheaper than copper and so most campgrounds are wired with it.

Copper-Versus-Aluminum Conductors

Now put taps evenly spaced along that tapered "pipe" The first guy gets the "full system pressure" only reduced by the loss in the larger diameter pipe for the distance from the circuit panel at the campground source to the first site (call it distance X). This site may not see ANY voltage drop ever no matter how many campers are on the parallel wired loop (provided the total amperage consumed by the loop never exceeds the circuit breaker's limit. Say 30 amps times 10 sites (300 Amps Available).

The last site however is a different story. While each site has 30 amps available to them, the pressure (voltage) is being reduced in the long run to the 10th site by 10 times the resistance loss per X feet.

So, say there are only 2 campers 1 on site 1 and 1 in site 10 each (for the sake of argument) pulling 20 amps.

The voltage each will see will be radically different even though there are 260 "extra amps" available. He will see the source voltage dropped by 10 times the line loss seen by camper one.

Much different for camper 10. Now he has low voltage due to line losses that are MUCH worse due to the heat in July (line loss goes up exponentially by temperature). What to do?

An autotransformer will take 1 amp of "available current" and convert it AT camper 10's site and boost the "effective" pressure at site 10 ONLY a few volts. NOTHING changes in voltage or amps available at any of the other sites. It is no different than site 10 turning on another light or turning on the TV in the bedroom as long as site 10 does not exceed the 30 amps available at his site.

Are you suggesting that someone CAN'T use two TVs at the same time because he is somehow "stealing" power from you?

Then the "power grabber" who is cooling his fridge with campground power is "Stealing Power" from me with that logic.

[TGR]

I wrote Progressive Industries and received this reply:

Dear Sir,
The problem some of our customers have had with after market generators, is because they use an inverter to produce ac voltage. If it produces a pure sine wave, there is no problem. Some generate a modified sine wave, or change to modified sine wave under a heavy load. When this happens, damage can occur to our products and it will not be covered by our warranty. So you must determine what is the method and output of your generator. We do not have enough engineering data to comment on other manufactures products.

Regards, Donald, Customer Support 919 267-6948

Yamaha says their inverter generators provide “clean” power with a “pure sine wave” and they also say their power is cleaner than regular generators. I expected that their generators would meet the requirements to work with Progressive Industries products. However, wmtire has correspondence that says the Yamaha EF2000is doesn’t meet Progressive Industries’ requirements. Since I have a pair of Yamaha EF2000is generators, I think I’ll consider the external model and not use it with the generator.

I can’t see their being an issue with autotransformers “stealing” power from other sites. Anything you turn on in your RV will reduce the voltage in a problem RV park’s power service. It doesn’t matter if you use your coffee pot, lights, A/C or an autotransformer, your using power drops the line voltage. If I thought drawing an extra amp of current using an autotransformer was stealing power, I wouldn’t turn on any appliances, with or without the autotransformer. I don’t think using a autotransformer is wrong.

[howie70]

Very well explained Herk!
I am debating whether I want to go with a Progressive Industries system or the auto-former. Regardless of which one, I want it mounted inside.
The Hughes auto former has an install kit, but if it states to mount it in a ventilated area. Not sure where I can do that. Also, seems it would be impossible to see the indicating lights unless there was a door or some sort of access to it.

[rana]

Lou. Where did you get that pic?? That's both absolutely hilarious and true. LOL

[wrapperman]

Herk, hi
First I would like to say that my thoughts and prayers are with your wife in what she is going through. I hope she has a wonderful life to come.
As for the thing we are talking about I hope you didn't think I am down on autotransformers. Far from it.
From your article are you talking about a brownout caused by the campground or power company?
If it the power company then I just don't understand how an AT can solve everyone's brownout. It will solve a few campers though.
I don't like to beat a dead horse so I'll move on and do more studying on other things.
Thanks for all your information.
My wife says I am hard headed, don't know why she says that. Duh
Hope y'all have a great camping season.
Thanks

[Herk7769]

Thank you for your thoughts. Our daughter was finally approved (after two months of tests) as a donor. Unfortunately not a direct match. So we have joined the Kidney pilot program where living donors are matched with living recipients in a cascade of kidneys with Laura getting a matching one at the end.

Our daughter's kidney will directly result in at least one and potentially many folks who are waiting for a kidney to get one in a cascade of matches.

You misunderstood me if you think an auto transformer will solve "everyone's" brownout problem. An AT will only help with YOUR brownout problem; and even then only if the brownout is in the "correctable range". (see attached for the input voltage and the output voltage for the Franks unit (the ONLY two stage boosted AT).

Only if everyone had one, and the brown out was in the correctable range would everyone's problem be "solved".

NOTE: Not all auto transformers are equal! The Franks unit has a MUCH higher Surge protection rating than the Hughes and the only unit with two stages of boost protecting you and boosting long after the single stage Hughes has kicked off line.

The Franks unit will be outputting 108 volts with a line voltage of 91 volts.
Now THAT is something!

I installed mine in a cabinet using the hole from the duplex outlet as a window to see the power/error and boost lights.

[Herk7769]

Originally Posted by howie70

Very well explained Herk!
I am debating whether I want to go with a Progressive Industries system or the auto-former. Regardless of which one, I want it mounted inside.
The Hughes auto former has an install kit, but if it states to mount it in a ventilated area. Not sure where I can do that. Also, seems it would be impossible to see the indicating lights unless there was a door or some sort of access to it.

Thank you. I was glad to help. Don't waste money on the Hughes install kit. You can buy the pigtails you will need from eBay at a fraction of the kit price. While you are there, buy a pair of volt/amp meters. They are dirt cheap so you can monitor your input amperage and output amperage.

200V 100A DC Digital Voltmeter Ammeter LED Amp Volt Meter Current Shunt | eBay

RV 12" 30Amp Male Pigtail | eBay

http://www.ebay.com/itm/30-Amp-RV-Fe...822eb6&vxp=mtr