192rd Converter & Solar Question

redbullsushi · 10-31-2016, 01:37 PM

My wife and I have a small piece of property and we are doing some boon-docking there in our RV. We have a Coleman 192rd, 2015. I am starting to put together a solar system that will run the unit but I can't really get a good idea of what size inverter it will take to handle the unit. We will not be running the AC being that we only hunt in the fall so we will basically run, outlets, water pump, tv, led lights and the fridge if I can't figure out how to run it on propane alone. I thought it might be helpfull if I knew how big the converter is on my RV so that I could match or slightly increase that wattage rating, but I can't find anything on the size of the on board converter. I know this is a random bit of questions but I want to make sure I buy what will work the first time.

thanks
Brad

ewarnerusa · 10-31-2016, 02:33 PM

Of the items you listed that you want to run, only the outlets run on 120V AC that would be supplied by the inverter. Unless you've got a 12V TV, then it plugs into a 120V AC outlet for power. So no inverter needed for the water pump and LED lights because they run on 12V DC electricity and the fridge can run on propane. The fridge does need 12V power to run though, whether on gas or 120V AC. It will probably have a switch right on front that says "Auto - Off - Gas." Auto means 120V AC that automatically switches to gas if 120V AC is not available, Off means off, and gas means propane only even if 120V AC is available. Don't use the inverter to run the fridge on 120V AC, it will complicate your solar/inverter project by having to design around its relatively large power needs (~300 watts) and running it on gas is more efficient anyway.

Your solar charging system needs to be based on your battery capacity, not the power needs, since its job will be to replace the power you took out of the batteries. Your battery bank is what you need to design around your power needs. From your description, it is minimal and should be served by 1x to 2x12V batteries depending on furnace use. Or 2x6V batteries in series. 200 watts of solar will match up well with 1x12V battery but will barely be the minimum if you have 2x12V or 2x6V batteries. With 2 batteries, try for 300+ watts. If you're using the furnace, plan on it potentially depleting a single 12V battery in one night.

Since the TV is the only 120V AC item you've mentioned, a small 300 watt inverter should work fine. The TV probably requires less than 100 watts to run. I suggest getting a pure sine wave inverter.

Your converter is not related at all to a solar charging system, although it will be critical to disable the converter if you wire your inverter up as "whole house" providing power to the entire 120V AC system. Otherwise the converter will try and charge the batteries by using power supplied from those same batteries via the inverter which will just end up in a power draining loop due to inefficiencies in the DC-AC-DC inversion/conversion.

redbullsushi · 10-31-2016, 10:32 PM

ewarnerusa,

I appreciate your quick reply and the information is valuable but there is something missing in my question I believe. What I am trying to do is run the RV as a whole unit off of a solar bank system and from what I understand without doing to major wiring inside my RV I will need to use an inverter so that I can plug in to the RV where I would normally use a 30 amp plug, but with a regular 120 extension cord. I will have limitations like the micro and ac running together but I want to build my solar system in a small shed and just plug into it like I would at a KOA. I hope this helps with my question and the lack of clarity I gave in the initial post. I do like the 300w 2+ battery idea as that was what I thought it would take to run the RV for a weekend, which is the amount of time we stay.
Also, one last thing, my fridge only has a push button that changes things and I have not tried whether or not I can cut it off electric or not. I would like to run this as a whole unit with only plugging in from outside. I know it will be 120 which will not handle everything at one time but that is how we use the RV when we travel to my families and we manage pretty well. Hope you can help me further with the size of the inverter to handle this load.
Brad

**wahoonc** · 10-31-2016, 10:39 PM

Welcome to the forums!

What is the model number of your converter? It is probably 45 amp or 60 amp.

However I do agree with ewarner, need to size the solar panels to replace what you use, or plan on using. You may have to up the size of your battery bank too, especially if you really draw down on it with the inverter.

FWIW most of my primo RV systems have been around 400 watts with 4 Group 27 batteries, typically used a 3,000 watt inverter and kept a close eye on what we used with it. My personal preference is to use as much LP powered stuff as possible and save the battery for the items that absolutely won't work on LP, like televisions and DVD players. I use LP for cooking, heating water and heating the RV. With my trailers I would quite often use a 100# cylinder (or two) for longer stays.

Aaron

redbullsushi · 10-31-2016, 10:44 PM

Yes I agree on the LP. Our RV will run most things on LP like cooking, hot water heater, furnace and even the fridge provided I can figure out how to make it use LP even when electric is available. So would the 3k watt inverter handle the internal converter and the ac together? I am not sure about the model number as my RV is not where I can look at it and I can't find my owners manual.

**wahoonc** · 10-31-2016, 11:08 PM

You want the converter OFF if you are on solar. The solar panel will charge the batteries directly through the the controller. If you turn the converter on you will create a feed back loop that will kill the batteries pretty quickly.

I have a simple diagram that explains this, have to see if I can find it...

But basically the solar provides the power to the batteries and then you pull power from the batteries via the inverter. When the sun doesn't shine you are depending on the batteries. To keep the fridge from defaulting to AC power you isolate that circuit so it isn't powered by the inverter. Sounds complicated, but once you get your mind around it, it is pretty straight forward.

Aaron

ewarnerusa · 10-31-2016, 11:17 PM

Solar panels are typically mounted right to your camper and go everywhere with you. Then they are working any time the sun shines to recharge your batteries. They are wired directly to your battery via a charge controller. Based on your original post, the TV was the only thing that required AC power. And that doesn't take very much. Now you've mentioned a microwave, that requires a lot of AC power. I would suggest forgetting the microwave along with the air conditioner.
The inverter can be wired up directly to your AC control panel and use a transfer switch, then there is no need to worry about plugging anything in. Or you could do what we do and just plug your Shore power cable directly into the inverter Outlet. Then it Powers the whole camper. But as stated a couple times, your converter must be shut off

redbullsushi · 10-31-2016, 11:21 PM

I am being educated so thank you for your time and effort. I was under the impression that the converter took the 30 amp power supply and turned that into 2 sources, 120 for wall plugs and "stuff" and 12v to charge the single battery on my RV. Am I wrong in this assumption? When I kill the breaker on the converter I thought that it killed the power that ran things like the tv and other wall unit items? I could be wrong but I can't get into the RV to test my half hearted theory of an idiot, ahhaha.

ewarnerusa · 10-31-2016, 11:27 PM

You're more or less right. But it will have no role charging the battery if you're not plugged into shore power or generator. In Your earlier reply to me, you describe a solar generator which you could just plug into as if it was your shore power. But that's not a typical way of using solar for your RV. Normally you install it on the camper and then it's with you working at all times.

Killing the breaker for the converter may have shut off your other outlets because they are all on the same AC circuit. If that's the case, you'll have to isolate the converter on to its own breaker. That's what I had to

Some reading for you.
http://www.marxrv.com/12volt/12volt.htm

redbullsushi · 11-01-2016, 12:20 AM

You are completely correct. We want to use a solar bank as the only electric source combined with the LP tanks to boondock for weekend hunting trips. I guess I need to find out if killing the converter breaker actually downs the other 120 systems in the RV. If it does then I am in a pickle as I am not an electrician and have no idea about setting it on its own system because that would involve moving those 120 outlets and such to their own electrical input that would be fed by the inverter, or I need to plan on enough power for a weekend that can absorb the loss going from inverter to converter to 120?

I think that statement makes sense....at least in my head.

**wahoonc** · 11-01-2016, 12:42 AM

Rocket science it ain't, but having a working knowledge of sparktricity is a plus.

Most of my units have had the converter on it's own circuit, make friends with an electrician! My background is construction and industrial maintenance so it comes pretty easy to me. It isn't too hard to wire up an automatic transfer switch that will control the inverter and the circuits you want. On my current motor home I am going to have to split a couple of circuits, takes a bit more to do that, but nothing too exciting.

Make a list of what you want to power up via the inverter, then go from there. Microwave is a power hog, is there anyway to do with out it? You will definitely need more than a single battery if you plan to camp for more than a few hours. At minimum you will need two, four would be better.

Whatever you do you don't want the converter to be on when running on the inverter.

Aaron

ewarnerusa · 11-01-2016, 01:33 AM

Moving the converter to its own breaker will be easier. We can cross that bridge with you later if needed. Solar is not used as the sole electric source, your battery is. The solar then recharges the battery so it's ready to use again.

redbullsushi · 11-01-2016, 01:52 AM

I do plan to use a bank of no less than 2 batteries in my woods shed that will be recharged by the solar system. I will not be running off the on board battery, but using the juice from the bank that is on the property. I will plug into my RV from the inverter like I would at a campground. I am going this route instead of using a gas generator or having the power company run lines to where we camp. This is only to power my RV for a weekend hunting trip and then it will sit during the week until we are back up for a hunt. I am basically making a small power plant for my RV that I hook up to.

What is the next step guys? I guess I could ask my RV dealer if they can split my power connections so that the converter does not turn on but all of the 120 things run from the extension cord fed by my shed solar bank of 2-4 batteries?

ewarnerusa · 11-01-2016, 02:14 AM

Well now you've re-complicated things by planning on putting things in your shed rather than installed on the camper. You will have no camper battery charging going on with your plan and the fridge and furnace will deplete them. Unless you do plan on using the converter for charging. Then you'll have design your battery/solar/inverter setup large enough to power it.
You should be planning on mounting the solar on the camper as well as that pair of batteries and inverter. Then it accomplishes your desired goal, as well as keeping your batteries charged and giving you mobile 120V AC via the inverter everywhere the camper goes.

More reading for you.
http://www.rv.net/forum/index.cfm/fu...g/1/page/1.cfm

ewarnerusa · 11-01-2016, 03:52 AM

I'm sorry. I reread my answer from earlier and I didn't mean to sound so rude. The link is to a page with a bunch of onboard solar charging systems for campers.

redbullsushi · 11-01-2016, 11:43 AM

But the furnace runs on LP and the Fridge does, but I have to check to see if it can be set to run off LP even when elect is available.

I don't really see how I can put this unit on my camper with only 2 batteries and have it be stronger/longer than building a 4 bank system with 300wts of panels? I believe that I can shut down the converter at night provided the furnace will still run on cold nights with LP along with the fridge, and then fire the converter up in the am to charge the on board battery that will run the lights and pump the following night. I have a long plan in mind and that is that I can build up my bank over time piece by piece until I have enough battery power to run for a weekend with no problem at our camp. My big concern is making sure that I purchase an inverter large enough to handle what the RV will need and then I can build the system up around it over time. For reference here is the RV that I have: Coleman 192rd Lantern Series

ewarnerusa · 11-01-2016, 08:03 PM

Everything that you're contemplating for the shed can instead be installed right on the camper. You can have your power station with you in the camper instead of just having it while parked at the shed. You can run your camper off a 4 battery bank, which is a lot and way more than enough for a long weekend, and have solar recharging the batteries anytime the sun is shining. You'll want 400+ watts of solar for 4 batteries though.

Your television requires less than 100 watts of electricity and can easily be run from a 300 watt inverter. This is a typically the smallest size of pure sine wave inverter. There are smaller rated modified sine wave inverters that may or may not work for your TV, but you can be sure that a pure sine wave one will work. You have mentioned microwave once and a couple of us suggested forgetting about that because it is such a power hog. I suspect up to 1500 watts or more at start up, so your inverter must be rated larger than that and have a proper installation to achieve it. That will be roughly 150 amps of 12V DC current that the inverter would be pulling, which shouldn't be a problem with a 4 battery bank, but your wiring must be up to the challenge. There are legitimate fire and electrocution hazards when trying to generate a lot of watts with a 12V inverter so proper wiring and installation will be very important. This is why we've recommended taking it out of your designs.

Maybe it will help to describe how we use our system, which is typical of solar installations for RV use. We strictly boondock and run off batteries and inverter for electricity and propane for fridge and water heater. I have 2x6V golf cart batteries wired in series for a 12V equivalent battery. On the camper roof I have 2x140 watt 12V nominal solar panels wired in parallel to a solar charge controller. The charge controller is then wired directly to the batteries. Any time the sun is shining, I have solar power charging and maintaining my batteries. The camper's 12V system is also wired to the batteries and operates normally. There is a 1500 watt pure sine wave inverter wired directly to the battery with 0 gauge wiring. We plug the camper's shore power cable right into this inverter when we are camping and it supplies the entire camper with 120V AC power just like when plugged into the regular power grid. But we know that I'm not really drawing power from the grid, I'm drawing power from the batteries via an inverter, so my available 120V AC power is limited by the inverter size rating and remaining battery capacity. This isn't enough to run the air conditioner, microwave, or electric water heater element, so I actually shut the breakers to those items off to prevent them from accidentally being turned on and overloading the inverter. I also have the breaker for the converter shut off for reasons already mentioned in this thread. We can camp pretty much without concern for electric supply, we run out of food or fresh water or the waste tanks fill up before electricity becomes an issue.

**wahoonc** · 11-01-2016, 11:33 PM

Okay... I think I see what you are trying to go...

What you are proposing is like trying to run a marathon with both arms tied behind your back, you can do it, but you are going to expend a lot of energy and take twice as long to do it.

If you want the solar and battery bank set on your site then I suggest that you mount the inverter in the trailer, turn the converter off. Then rig up a 12 volt connection from the battery bank/solar setup to your trailer. Not hard to set up using the Anderson Powerpole plugs.

The problem with plugging the trailer into to an inverter and using it to power up your converter (along with everything else) is the expense and the power losses. That is probably the least efficient way to do it. You will need to size the system at least 50% larger than is really needed, with a corresponding cost. Check the price difference between 400 watts of panels and 1000 watts of panels, each battery you buy is going to be $200+ for a good one. Solar runs around $1.50 a watt for panels, not including a controller (necessary) any wiring and other odds and ends.

With 12 volt power efficiency is your friend, anything that cuts into that efficiency is costing you serious money.

A 3200 watt inverter generator and another battery for the trailer would be way more cost effective. You can buy a Champion 3100 watt remote start inverter generator for ~$900, another battery for the camper is ~$200. You can plug the camper directly into the generator and run anything you want, possibly the A/C too. The batteries will get charged up in a couple/three hours then you can turn it off. You also have the generator to for other uses, like running power tools, or during a power outage at home.

When I had my Airstream I use a Honda 2000 watt, never had to run it more than 3 hours a day to top my dual batteries back up. It would not run my air conditioning, but it could handle everything else if I was careful.

Aaron

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