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Author Topic: 50 amp versus 30 amp  (Read 7332 times)

Offline Midwilshire

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50 amp versus 30 amp
« on: November 02, 2013, 06:20:15 PM »
We're ready to start pulling wire on our conversion.  I've laid everything out for 30 amp, figuring that it would probably suffice for our loads.  But the Magnum MS4024 inverter we have can run two hot legs no problem, and recently I've begun to think we should wire for 50 amp in case our needs grow in the future.  Never having been in an RV campground, I don't know the popularity and availability of 30 versus 50 amp.  So my question: if you were wiring a bus fresh (not yet converted), would you go with 30 or 50 amp, and why?

Thanks in advance.
Michael & Gigi
1978 MCI-5C "Silverliner"
Full-timers in the DC area

Offline luvrbus

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Re: 50 amp versus 30 amp
« Reply #1 on: November 02, 2013, 06:40:53 PM »
Go with 50 amp if the need ever arises you can run 2 ac's easy with 50amps the 30 amp for 2 ac's is a little iffy sometimes on a real hot day 
Life is short drink the good wine first

Offline John316

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Re: 50 amp versus 30 amp
« Reply #2 on: November 02, 2013, 06:41:06 PM »
Quick answer?

50 amp. You can put a 30 amp adapter and run with it any day, and utilize all of it. Not so with 50. Always easier to scale back, IMHO, than to wish you had built better....

FWIW

John
Sold - MCI 1995 DL3. DD S60 with a Allison B500.

Offline gumpy

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Re: 50 amp versus 30 amp
« Reply #3 on: November 02, 2013, 07:20:56 PM »
50. No question.
Craig Shepard
Located in Minnesquito

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Offline robertglines1

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Re: 50 amp versus 30 amp
« Reply #4 on: November 02, 2013, 07:25:24 PM »
50 is the new standard.  Hard to upgrade later.  Bob
Bob@Judy  98 XLE prevost with 3 slides --Home done---last one! SW INdiana

Offline Midwilshire

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Re: 50 amp versus 30 amp
« Reply #5 on: November 02, 2013, 07:33:26 PM »
Thanks fellas.  50 it is.
Michael & Gigi
1978 MCI-5C "Silverliner"
Full-timers in the DC area

Online TomC

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Re: 50 amp versus 30 amp
« Reply #6 on: November 02, 2013, 09:49:43 PM »
Because I use my roof A/C's going down the road, my 10kw genset is wired straight 120vac, along with all wiring. I only use one leg of 50amp, which when plugged in is more then enough power. 30amp can run 2 roof airs, or any 2 electrical items at a time, but 50amp works well. Have never been at a loss for power. I like it so much, I'm wiring my truck the same way. Then you never have to worry about balancing the two legs on either the power pole or the genset. Good Luck, TomC
Tom & Donna Christman. '77 AMGeneral 10240B; 8V-71TATAIC V730.

Offline Len Silva

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Re: 50 amp versus 30 amp
« Reply #7 on: November 03, 2013, 08:00:05 AM »
There is no reason that you can't have the generator wired for 120 and connected to both hot leads and the shore power wired for 240.
Balancing the load only matters to your generator, the power company doesn't care about your little 30 amp load.

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Offline belfert

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Re: 50 amp versus 30 amp
« Reply #8 on: November 03, 2013, 08:12:45 AM »
I did as Len suggested and run the 120 volt from my generator to both hot leads.  I have a 50 amp to 30 amp converter that energizes both hot leads too.  I can run two A/C units on a 30 amp circuit, but add in much else like the fridge and the breaker on the 30 amp circuit will trip.  (I only have a 30 amp outlet at home and have had to make the trip to the basement a few times to reset the breaker in the house.)

I like Tom's idea for planning to use only one side of a 50 amp plug although I wonder if that would be enough for three rooftops and other power needs when it is 105 degrees outside?
Brian Elfert - 1995 Dina Viaggio 1000 Series 60/B500 - 75% done but usable - Minneapolis, MN

Online TomC

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Re: 50 amp versus 30 amp
« Reply #9 on: November 03, 2013, 08:17:57 AM »
I can easily run 3-13,500 roof tops in over 100 degree weather on the one leg of 50amp. I usually only need three to initially cool the bus, then two works just fine. Good Luck, TomC
Tom & Donna Christman. '77 AMGeneral 10240B; 8V-71TATAIC V730.

Offline Len Silva

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Re: 50 amp versus 30 amp
« Reply #10 on: November 03, 2013, 08:33:20 AM »
Tom,
I'm not criticizing your installation, there is no doubt it will work.  I just don't see any advantage except the possible savings on a 3-wire shore cord instead of 4 wire.

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Offline belfert

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Re: 50 amp versus 30 amp
« Reply #11 on: November 03, 2013, 08:40:27 AM »
I know I couldn't keep three roof tops running from my 66 amp generator, but I also know a large part of it was that a generator produces less power at altitude and at high temps.  We tripped the breakers on the generator a few times, but a bigger issue was tripping the 20 amp breakers for each air conditioner.

A 50 amp shore connection generally has a lot more surge capacity than a generator.  Of course, shore power can have low voltage if an RV park is not wired properly to handle a hot day with lots of air conditioners running.
Brian Elfert - 1995 Dina Viaggio 1000 Series 60/B500 - 75% done but usable - Minneapolis, MN

Offline luvrbus

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Re: 50 amp versus 30 amp
« Reply #12 on: November 03, 2013, 09:27:04 AM »
Lmao how in the world can you run 2 even 13,500 btu roof airs off a 30 amp service my Penguin with the 410 freon draws 15.6 amps @ 85 degrees then it goes up almost 1 amp for every 5 degrees over 85 degrees that is from Dometic not me.

My old Penguins would draw 14.3  ea at 85 degrees and go to 17 or 18 amps in the AZ heat so how can you draw 30+ amps from a 30 amp service ?
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Offline Len Silva

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Re: 50 amp versus 30 amp
« Reply #13 on: November 03, 2013, 09:36:29 AM »
Tom is saying he can run 3 off one leg of a 50 amp service, not 30 amps.  It should work but that one leg is being needlessly stressed when splitting it over two legs would be more efficient, not to mention less voltage drop at the units.

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Offline luvrbus

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Re: 50 amp versus 30 amp
« Reply #14 on: November 03, 2013, 09:41:36 AM »
He also said he could run 2 off 30 amps in another post Len I want to know how he does it  the only way I see that happening here in the summer is 1 at time
Life is short drink the good wine first