Added an Autoformer - Page 2 - Montana Owners Club

sreigle · 07-15-2005, 05:40 PM

Thanks, Bill, that's a very generous offer and I appreciate it. I just did a quick check on S&T out of curiosity. From town to town we're 2,366.4 miles apart. Just a bit too far..

Ontheroad · 07-17-2005, 04:28 AM

After a month of low voltage in a 30 amp state park (we'll be here another two months), and seeing your posts I decided to take the plunge and buy a 30 amp autoformer. $359 at CW with $1 shipping. I thought about the 50 amp model, but I've never had low voltage at a 50 campground. Maybe just lucky>
Steve & Ellie in western Maryland for the summer

8.1al · 07-17-2005, 07:39 AM

You're right sph77. I never gave it much thought but I have never seen low voltage when I had 50 amp. You saved yourself some money and I bet that thing weighs a whole lot less than my 50 amp

sreigle · 07-17-2005, 09:20 AM

That info helps me, too. I'm laboring over whether to go with the 50 or the 30. Thanks.

Bill and Ann · 07-18-2005, 01:39 AM

You know I have been reading the posts and it got me wondering. If you have a 50 amp autoformer and you go into a park with 30 amp service you wouldn't want to use your autoformer as it would be on boost all the time. Assuming you use a 50/30 reducer. If so, I guess I am glad I got the 30 amp autoformer.

Ontheroad · 07-18-2005, 09:04 AM

I'm not sure how that would work either. BTW, I received an e-mail from CW that said my autoformer was on back order and would be shipped 8/5. Oh wellllll, I guess there is a shortage.
Steve

Montana_2785 · 07-18-2005, 10:00 AM

Quote:

quote:Originally posted by Bill and Ann

You know I have been reading the posts and it got me wondering. If you have a 50 amp autoformer and you go into a park with 30 amp service you wouldn't want to use your autoformer as it would be on boost all the time. Assuming you use a 50/30 reducer. If so, I guess I am glad I got the 30 amp autoformer.

Bill, using a 50 amp autoformer with a 30 amp park service would NOT mean that the autoformer is boosting all the time. An autoformer will only boost if the input voltage it sees drops below some voltage (I think someone said 118V???).

If you had an EXCELLENT 30 amp service, an autoformer (even the 50 amp one) would never boost as long as the voltage did not drop too low. Even if you tried to draw more than 30 amps and caused the main pedestal breaker to pop.

At the other extreme, if you had really bad 50 amp service and you were drawing only 1 amp but the voltage dropped below the magic boost voltage point, then the autoformer will do its thing.

The only difference between the 30 and 50 amp autoformer is how much power can you use with it. If you are going to use more than 30 amps at once, then you HAVE to use the 50 amp capable autoformer. Otherwise, you can use the 30 amp capable model.

Eric

sreigle · 07-18-2005, 11:21 AM

So what happens to/with the 30amp autoformer if you draw more than 30 amps? Does it have its own breaker? If not, then I'd pop the park's breaker but wonder if there could be damage to the autoformer?
Thanks.

Glenn and Lorraine · 07-18-2005, 11:48 AM

I'm do not understand why anyone with a 50 AMP rig would even want to consider a 30 AMP Autoformer. If you're 50 AMP buy a 50 AMP and if you have a 30 AMP rig than buy a 30 AMP. Is it worth saving a few extra bucks when sooner or later you will regret not getting the proper unit.

My only question is this....
If the park's voltage drops to 100 volts the Autoformer will only boost it up 10% or 10 volts to 110 volts. Still not enough to run the AC.
My question...If I add a second Autoformer will it than boost the voltage another 10% to 121 vlots?
BTW-One afternoon the voltage at out last park did drop to 100 volts but as we were going out we hadn't the need for AC that day and by evening the voltage had returned to 115.

Montana_2785 · 07-18-2005, 12:09 PM

Quote:

quote:Originally posted by sreigle

So what happens to/with the 30amp autoformer if you draw more than 30 amps? Does it have its own breaker? If not, then I'd pop the park's breaker but wonder if there could be damage to the autoformer?
Thanks.

As long as you have a 30 amp breaker in line, then I would think that it would survive long enough for the breaker to protect it. It wouldn't be any different than when we turn on one too many high draw items now and pop a breaker. As long as everything in the line is rated for 30 amps then things will be OK.

But, if you have 50 amp Monty and you plugged your 30 amp autoformer into a 50 amp service using an adapter, you are most certainly playing with fire!!!

Eric

Montana_2785 · 07-18-2005, 12:13 PM

Quote:

quote:Originally posted by Glenn and Lorraine

[...]My only question is this....
If the park's voltage drops to 100 volts the Autoformer will only boost it up 10% or 10 volts to 110 volts. Still not enough to run the AC.
My question...If I add a second Autoformer will it than boost the voltage another 10% to 121 vlots?
BTW-One afternoon the voltage at out last park did drop to 100 volts but as we were going out we hadn't the need for AC that day and by evening the voltage had returned to 115.

On our old TT, I had a 30 amp surge protector with a high & low voltage cutoff. If something like this was in the line before your autoformer, then it could still cut off service to the rig when it is too low for the autoformer to properly boost voltage. The low voltage cutoff was at 103 volts. It allowed voltage to go below for 5 seconds before killing power. Then it would kill power right away when voltage exceeded 130 volts.

Ontheroad · 07-18-2005, 03:11 PM

Glen,
Even with a 50 amp monty, if you're hooked up to a 30 amp service, would'nt the 30 amp autoformer be sufficient? I'm confused.
Steve

Glenn and Lorraine · 07-18-2005, 03:19 PM

Steve, your confused? Well so am I. I have no idea whether it would be sufficient or not. I just wonder what happens when you try to pull more than 30 amps through the 30 amp unit. Why have a 50 amp rig if you can't use it?
These questions maybe better asked of the Hughes company.

jackw87 · 07-18-2005, 04:09 PM

The 50 will work on the 30 sites if you try to pull 50 from the 30 amp connection wiu will blow the braker on the park box

sreigle · 07-18-2005, 07:11 PM

I guess my question was more theoretical than anything else, wondering if it would be fairly easy to blow that expensive piece of equipment through stupidity or whatever reason. For example, if a true 50 amp Montana were attached to a 30 amp autoformer which in turn was attached to the park's 50 amp outlet via an adapter. Thus a 45 amp draw would not blow the park's 50 amp breaker nor would it trip the Montana's 50 amp main. So does the 30 amp autoformer overheat and fry its electronics, or does it smoke it, or catch fire, or all of the above? I'd just like to know the possibility.

Glen, in our situation I think the 50amp autoformer would be overkill even though we have '50 amp service'. We have the older electrical system where 20 amps of our 50 are directed to the second AC prep. The other 30 go to the rest of the coach. Since we have the prep but do not have a second AC unit we're really running the coach on 30 amps despite the '50 amp service'. So I usually connect to the 30amp outlet when available. For us as we sit right now the 30 amp autoformer meets our needs. If we someday added the second AC unit then I'd wish to have the larger autoformer. But until then I question whether I'd want to spend the addtl $100 for the larger unit, whether I'd want to lug around the heavier unit, etc., when I can't use it's additional power. Make sense?

Bill and Ann · 07-19-2005, 01:59 AM

Does to me Steve. I guess I opened up a bee's nest when I questioned the 30 vs. 50. I have the 30 amp autoformer as I don't have or intend to have the second air. I always plug into the 30 amp at the park and use the 12" adapter 50/30 cord as I only carry my 30 amp lines.

DCP · 07-19-2005, 02:21 AM

After reading everyones comments, I'm a little confused. Pardon my stupidity on this one, but if I buy a 50 amp Autoformer for my rig and plug it in a 30 amp park outlet, is it going to help the voltage problem at 30 amps? If 30 amps is more the norm at most parks, should I go that route?

Montana_2785 · 07-19-2005, 05:08 AM

Quote:

quote:Originally posted by DCP

After reading everyones comments, I'm a little confused. Pardon my stupidity on this one, but if I buy a 50 amp Autoformer for my rig and plug it in a 30 amp park outlet, is it going to help the voltage problem at 30 amps? If 30 amps is more the norm at most parks, should I go that route?

The 50 amp autoformer is one that has bigger internal wires and a bigger internal transformer. It can handle loads UP TO 50 amps. If you are using it with a 30 amp service from the park outlet, it will be perfectly fine. It will handle more power than the park can supply. It is a matter of paying more $$$ and lugging around more weight for a beefier unit.

As for what you want to get, what is your rig capable of?

sregal & I have "50 amp service" (said tongue in cheek) since what we have is a 30 amp leg for most of the coach and a 20 amp leg that is only used for the second air conditioner and (I think in my case) the washer dryer outlet. The main breaker in my breaker box also only has 30 amp and 20 amp breakers. Since I have neither second A/C or W/D, I only use the 30 amp side of my electrical system. If I never modify my electrical system I would be perfectly fine getting the 30 amp autoformer as I would never be able to overload it. My internal main breakers will pop above 30 amps and protect the autoformer.

The newer Montana's that have real 50 amp service have TWO 50 amp capable legs and (I'm assuming as I haven't traced the wiring in one) the appliances are more evenly distributed between the two legs. That being said, there are several ways you can supply power to the true 50 amp rigs (with internal 50 amp main breakers):

1) Full 50 amp hookup. Your 30 amp autoformer will not work here as it only has one circuit internally instead of the two circuits (or legs) that the full 50 amp service has. You won't even be able to plug it in.... You will HAVE to get the 50 amp autoformer if you want one to use full 50 amp service.

2) Hooked up to 30 amp park service via a 30 amp to 50 amp adapter cable. This cable takes the single circuit from the 30 amp park plug and attaches BOTH internal legs of the Montana to it. A real 50 amp service is 220V (two 110V legs that are 180 degrees in phase apart.) A stick house could not do this as there could be 220V appliances. We can do this for our RV since we don't have ANY 220V appliances. We simply view it is two SEPARATE 110V legs and it doesn't matter if they are 180 degrees out-of-phase (like from a 50 amp plug) or 0 degrees (both attached to the same 30 amp park plug). In this case, we hook up the 30 amp autoformer to the park plug and plug in our 30 amp to 50 amp adapter to the autoformer. In this case, the park plug 30 amp breaker will protect the autoformer from overload if you forget and turn on too many things.

If you were using a 50 amp autoformer on 30 amp service, you just use the proper combination of adapters to go from 30 amp (from park plug) to 50 amp outlet, plug in the 50 amp autoformer, plug in the Monty with its 50 amp cord or use a 50 to 30 amp adapter and use a 30 amp cord to go to the Montana.

3) NOTE: NEVER EVER DO THIS ONE!!!!
This one makes no sense, but it is possible to get a combination of adapters to do it. Start with a 50 amp (at the park plug) to 30 amp adapter. This takes only ONE of the 50 amp legs and puts it on a 30 amp style plug. Plug in a 30 amp autoformer. Plug a 30 amp (on the autoformer) to 50 amp (to the RV) adapter. As above, this connects the single live electric source to BOTH internal legs inside the RV. THE PROBLEM WITH THIS IS THAT THE PARK PLUG HAS A 50 AMP BREAKER AND THE INTERNAL RV MAIN BREAKER IS ALSO 50 AMP. THERE IS NOTHING TO PROTECT THE 30 AMP AUTOFORMER FROM OVERLOAD.

Eric

sreigle · 07-19-2005, 05:47 AM

Eric, number 3 is the question I posed as I hope to find out how well protected the autoformer is in this kind of situation. I'd never hook up that way but how well protected is it. I'll try to do some research on that when I get a chance.

Bill, I appreciate you opening that 'bees nest' since I like to be as knowledgeable as possible before I spend much money.
I hope I didn't create a problem by posing the questions.

Ontheroad · 07-19-2005, 07:08 AM

Thanks Eric,
Since I have an older "50 amp" unit that really only uses 30 amps, the 30 amp autoformer should do well for now. The only debate in my head now, is maybe I should spring for the 50 amp unit now ($180 more) that I will need on my next monty.
Steve

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