30amp or 50Amp service with solar....

[Rvlegaleagle]

Am new to RVing and after finally selecting my rig I was wondering if I can get some experienced and knowledgeable comments to my particular situation from all of you.

Will be ordering a new gas Newmar Bay Star shortly so I have some wiggle room when it comes to requesting certain changes being made to the STD build. One option is to order the 30amp versus the 50amp system.

Although I was a boater all my life and did some tent camping as a youth in campgrounds, I never stayed in a RV. My boat had 30amp shore power with a converter, no gen set.

I don't think a RV park is my style, way too crowded and I have 2 dogs. I will want to boondock, dry camp or dispersed camp. Federal forests, National parks, BLM, State or local campsites, harvest host etc. Although born and raised on Long Island, New York, I am getting out of here and heading WEST where I will be doing most of my RVing.

Game plan is to get a post pickup solar setup with 750-800w array, 440amp (6v) battery bank AGM or possibly 400amp (12v) lithium down the road. I could also get 660amp (6v) or 600amp (12v) lithium down the road with the same array.

Leaving the particular solar setup components aside, I am wondering which way to go on the 30amp or 50amp order from the factory?

OPTION 1: Get the 30amp system. There will be 2 A/Cs, one 15000 btu and the other 13.5 and I think I can get the 13.5 to be a separate line of its own with a separate second 30amp plug in and cord. The gen set (onan 4000) and the first 30amp line plug in will only run the 15000 and all other a/c powered components.

The second 30amp and 13.5 a/c will run if plugged in and will also be connected to the inverter/charger with a soft start prior to the transfer switch so it can run off the batteries with solar on good days The inverter/charger will also be setup so it can run, at my selection, EVERYTHING A/C except for the water heater and 15000 A/C. Note: Ref will NOT be a residential one but a 3 way RV ref.

OPTION 2: Get the more expensive upgraded 50amp service with the larger 5500 gen set. The only thing the 50amp service would be able to also run is the second 13.5 A/C. Any other option that required a 50amp service such as the fireplace/heater is NOT being ordered.

I can still have the 13.5 A/C run off the batteries with solar on good days as described in option 1 and when at a park plugged into a 50amp service or when running the 5500 gen set. I have been told that in many places there is only a 30amp plug in service available and that while there is an adaptor from a 30 to a 50, you can't run both A/Cs and/or have to limit your use of other A/C components. Also, I don't think with the 50amp service I can also have that separate 30amp plug in and cord that just runs the 13.5 A/C?

I also believe that all the wiring sizes from the panel that run to all the individual A/C components is the same size wire whether you get the 30amp or 50amp service? Only some breakers and wiring from the 50amp post plug in to the panel are different between the 30amp and 50amp service?

PLAN: My goal is to be able to use solar and batteries as much as possible for ALL A/C components, including the 13.5 A/C on good days. The second goal is to use a smaller gen set, if possible, to run ALL A/C components and to use it as little as possible. The final goal is to be economically and power efficient as possible, weigh as little as possible for OCC purposes and boondock as long as possible.

I know this was rather long and I put in as much information as possible for your consideration. Any comments, experiences and knowledge from you would be greatly appreciated Thanks in advance.

[Mr_D]

We had a 2000 Dutch Star with a 2000 watt inverter and two U-2200 batteries. CW installed the inverter and didn't split circuits so we could run a 13.5 heat pump off the inverter, for less than 20 min. Then the battery was depleated and the inverter shut down.
To run a air con off a battery bank is going to take more solar and batteries than your rig can carry.

[Skip426]

I'll preface this info by saying that , I don't use solar , and have a limited understanding of the amount of battery power needed to run a roof air conditioner, for any length of time , the size of inverter required to provide that roof air power, or the solar array needed to recharge/keep up with the draw on the batteries.
So, JMHO.
The price of this equipment, and modifications to a new coach to get it operational is and it's weight could eat up most of the coaches CCC.
Any newer Class A with a single roof air conditioner and only 30 amp service, could have limited re-sale value.
EDIT : And I see my slow typing , and a run for a second cup of coffee , has put me in second place with this post.

[drivintin]

I agree with Mr_D, you are not going to be able to run your A/C off if batteries and solar. There have been some tests done on this, and you can make it work for a short amount of time, but you are going to kill your inverter and batteries very quickly.

Personally I would do 50 amp, mostly because then you actually have two 50 amp 120v lines coming into the unit over the single 30amp 120v line. Granted you have to dogbone it when staying places that don't have 50amp, negating the extra line, but it is very well worth having when you are places you need both A/C units.

[MisterT]

agreed, having two 30a incoming shore power lines only provides up to 60amps of power, much less than the typically / normal 50a shore power, which is up to 100amps of power(two 50a lines via the double pole breaker).

so, you would be 'losing' 40% or 40 amps of potential power, at least when at a park or campground with 50a power.

also, using a 30/30 to 50a dogbone adapter when you have access to two 30a shore power lines is optimal, since the coach then shares this 60amps max across the board, and is not relegated to a specific side of the breaker box, or AC unit, etc.

And, if you go the route of two 30a power plugs in your coach, and only have access to a single 30a shore power line, you will not have any options other than only a single 30amp outlet to pull from.

I have several/many adapters, dogbones, and even 30a and 50a double pole breakers and heavy gauge 50a wire, for the many scenarios we might run into... we don't use them all very often, but when they're needed, it's very nice to have them. Running two AC units is probably the single biggest need that most of us have when it comes to how many amps we can bring into the coach. Electric heating is a close second.

[RMD3819]

Disclaimer: We boondock only between campgrounds.

Did Newmar tell you they would build the coach with two 30A? Two shorelines? If not and you DIY this will likely void the warranty.

My wife was all over the boondock solar thing when we were ready to buy. She gave up after being told it is impossible to have a portable solar setup that will run an A/C.

My advice is get the 50A if nothing else for the larger generator. No one ever says I wish I had a smaller generator.

[Rvlegaleagle]

Would never void the warranty

Thanks for what you have said on here so far Would like as much constructive criticism and options as possible, it actually helps

Let me add the important solar stuff....going with Magnum all the way because it all connects to and is controlled from one display. (ME-ARC). The connections between the MTTP solar controller (PT-100) and the 3000 (MSH3012) hybrid inverter/charger with auto gen start switch are simple and then you have a complete and integrated solar system.
(leaving the panels and battery bank out of the equation)

Given this setup you can understand the choice between the 30 vs 50 amp system and costs, functionality, weight and purpose of the 4000 vs 5000 gen set.

I don't know for sure but I have heard, that campgrounds with a 30amp only shore power can run the 15000 A/C and everything else 12v and 120v in the rig. (regular micro not convection maybe use it for 2 minutes to heat something up, Not into hair dryers, the hot water heater will not be run on electric nor will the 13.5 A/C run off that 30amp cord). In that instance, it is my understanding that when there is 30amp service there is usually a 20 amp plug in there as well which with an adaptor from 30 to 20amp I can plug in the second shore power cord and run the separately wired small 13.5 A/C with soft start as it will be the ONLY thing on that line.

If there is a only a 50amp service available at a campsite, then you can, I think, use a Y adapter from the 50 to two (2) 30amp power cords run to each 30amp plug in to the rig and do the same thing. Everything will work. While it is true you get 100 amps out of a 50amp service and 12000 watts (6000w on each leg)....my rig is set up so that I don't think I have a need for such power while at a campsite? Maybe I am wrong.

Boondocking with Gen power at 4000w will run the 15000 A/C and everything A/C and 12v and charge the batteries in the am for a few hours (2-3). With the hybrid inverter/charger on a good solar day I can further charge the batteries at a higher charge rate than the gen did, run the A/C stuff and sneak in some 13.5 A/C time in the afternoon in an already cooled down coach.

On a bad solar day, I can just run the gen with just the 15000 A/C but typically on a bad solar day the sun, by definition, is not out much or it is raining If it is a half good day I can run the 4000 gen for the 15000 A/C AND use the solar to boost it so I can also run the 13.5 A/C.

Would rather save the $$$ by keeping the STD 4000 30amp and not upgrading to the 50amp 5500 and put it towards the solar system and battery bank.

All comments are welcomed and really appreciated The more the better IMHO.

[Old Scout]

Believe you are putting way too much into what even 800watts of solar will do for you in the 120v AC world--that's roughly 8 120v amps--not much. Go with 50 amp service and the largest generator that will fit.....Frankly, I am not even sure what you are talking about regarding "integrated systems" and various dog-bone connections. There are hours of reading on this forum about solar and dozens of outside links with more info--but to my knowledge, none talk about running AC unit[s] on batteries......except with very large coaches?????

[vsheetz]

We boondock - have had both 30a and 50a coaches - and have solar experience.

Solar and battery are not practical for supporting air conditioning.

Get the 50a. When you do have 50a service it will be welcomed. The larger generator is a good thing as it will handily support two air conditioners.

As for solar. I have 1500w on current coach. Had 600w on previous coach. I am in the camp of go big when it comes to solar array. Mitigates cloudy days, shaded sites, shadowing, low sun winter months, etc.

[pasdad1]

Yes, forget about running air conditioning on batteries and solar in your case. There are a very few on this forum with the setup to do it, and then they can only run it for a few hours at best....and I'm talking major $$$$$ in lithium batteries and HUGE solar arrays (much larger than you have been dreaming of)

It's better to park in the shade if you can, otherwise the heat gain from the sun is more than one 13.5k air conditioner can overcome.

For the money you are spending on a new gas unit, you might want to think about a larger used diesel coach. It can carry much more weight, has much larger basement storage (no drive shaft to get in the way) and diesel generator can draw from the 100 gallon main chassis tank.

The extra weight capacity and room could be used to carry many more batteries.....getting you closer to your goal of energy independence. In the winter, a diesel fired aqua-hot system can run much longer before fill-up than a propane heater system (again because diesel fuel stores more energy per gallon than propane, and the tank is larger)

[BillJinOR]

Take the 50 amp ( 2 50 amp circuits ) I have 1000 watts of solar and over 800 amps of batteries and wouldn't think of any ac use. Your not the first to have this great idea. It doesn't work. But it's your coach I'll let you make the mistakes $$$$$ and tell me I'm wrong !! Please I hope I'm wrong! I'd love it to work that way and will do it as soon as it's possible without a new bank loan . Call AM solar or some other reputable all be it expensive solar outfitter and get the real deal rundown. They can give you the specs on what it takes for your order and the solar conversion

[MTK46]

I have to agree running A/C's off of batteries isn't what the vast majority or RVers do.
I can tell you that with my 50 amp service & 3 13,500 A/C units I can run 2 off of 30 amp service at the same time. Each one runs off of a different leg. Now yes I have to watch other items that I'm running but it can be done.
I would go with the 50 amp service hands down over a 30 amp one.

[drivintin]

So speaking generally about power, I have a Thor 33.3 it has two 13.5kwh A/C units. I also have upgraded and have the MSH3000, ARC, and MagWeb.

On 30amps, if the sun isn't hitting the circuit breaker, I cross my fingers, and do a little dance to the Gods, then I can get both A/Cs to run on low. Sometimes it works, sometimes it doesn't. I then set my inverter to only use 5 amps and use the battery for everything after that.

On 30amps remember you only have one load line, a neutral, and the ground. So don't have the combined amps like you do in the 50amp line. Also if you get one of the adapters that combines the 30 with the 20 you have to have a 50 amp cable because it uses the two load lines in the cable to send it to the RV. Also that hardly ever works because they share a neutral, and this pops a GFCI outlet.

Now if you are actually running to sperate power lines out there with the secondary A/C on a dedicated line you might be ok. Just be careful with your groundings and how you wire things.

[twinboat]

PAverage running watts of a 13500 BTU air conditioner is 1500 to 2000 watts.

Your going to need that much and more solar to maintain your batteries while the AC is running.

Maybe it's cool and it only runs 1/2 the time. You still need 750 to 1000 watts.

1000 watts at 120 volts is 8.3 amps. Convert it to 12 volts and your drawing 83 amps at 12 volts plus 10 to 15% inverter loss.

800 watts of solar will not cover the AC load, when running and hardly replace what you used when the AC is off. You will only get full output from your solar if parked on the equater at noon. Expect 60% to 70 % from them.You will be discharging your batteries.

400 AH of battery will give you 200 AH usable. Draw 40 amps for 5 hours and your at the 50% point.