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tnky03
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# Posted: 19 Jun 2013 16:40
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We are close to completing the wiring of our cabin and have some questions. Can the wires from breaker box be wired into an inverter and if so does it have to be a certain kind? If we understand right our solar panels will connect to a charge controller then wires to battery bank, then to inverter. If anyone has suggestions or input we would appreciate it. We are totally new to using solar and though hubby has wired houses over the years this is quite different and we want to get it right. We will use two 100 watt panels, haven't bought charge controller or inverter yet. Will probably use four deep cycle batteries to have four LED lights, charge laptop, small tv and dvd player a few times a week and a small fridge, maybe 10 cu. ft. Other than the fridge we currently run all the rest with a 750 watt inverter (cheap one) and two 12 volt marine batteries, charge occasionally with car.
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Dillio187
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# Posted: 19 Jun 2013 21:06 - Edited by: Dillio187
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yes, you wire the breaker box into the inverter. I have my cabin like this and it works just fine!
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razmichael
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# Posted: 20 Jun 2013 14:27
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tnky03, Although not specifically asked (and I apologize if you know this), the cable between the batteries and the inverter will be very heavy duty battery type cables. The size will depend on the distance between the inverter and batteries (keep this as short as possible) and the maximum draw available by the inverter. If your budget allows use a heavier gauge than suggested if think you might want to upgrade the inverter in the future as this cable can be expensive.
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tnky03
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# Posted: 23 Jun 2013 19:17
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Thanks so much for the info. We hope to keep the cable distance 3-4 ft. How large an inverter do we need? Our budget is tight but we do for sure want to get one that can handle what we need. Are their specific inverters meant for being wired directly? Maybe another silly question, but do you just mount all the extra stuff (charge controller, inverter) on the wall near breaker box? I've seen some pics of setups by others but it looks a bit confusing. I had thought of maybe getting hubby to construct a box, of sorts, to hide these things but want to be sure that would be safe.
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ICC
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# Posted: 23 Jun 2013 20:12 - Edited by: ICC
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Quoting: tnky03 a small fridge, maybe 10 cu. ft. Other than the fridge we currently run all the rest with a 750 watt inverter (cheap one) and two 12 volt marine batteries,
Quoting: tnky03 How large an inverter do we need?
Electric refrigerators don't mix well with small solar power systems.  They typically use a kilowatt-hour a day, maybe more or less depending on the ambient temperature and a few other factors. It can be done but you need more than a few golf cart batteries Look up the energy guide sticker that comes on all refrigerators, divide the kWh by 365 to see the likely number. That is why many, maybe most off gridders use propane fridges.
Note refrigerator motors usually have a shortened life when used with power from a square wave, so-called modified sine wave, inverter. The motors run hotter and also may make more noise. They also use more battery power with a square wave than they do with a pure sine wave inverter.
The charge controller and other electronics should be kept away from the inverter. In particular do not mount electronics above the batteries. One reason is the small amount of acid vapor that could rise from the batteries while undergoing charging. Another reason is charging produces flammable hydrogen and electronics like controllers and inverters may contain relays that can spark.
The only device close to the batteries should be a type T fuse on the positive cable to the inverter.
Maybe place batteries in a vented to exterior box.
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tnky03
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# Posted: 23 Jun 2013 20:27
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Quoting: ICC The charge controller and other electronics should be kept away from the inverter. In particular do not mount electronics above the batteries.
Our batteries will be in a box outdoors with wires coming into cabin, so then it should be ok to mount charge controller, inverter on the wall, I'm guessing. Thanks for the help, wish better news on fridge, lol. We'll have to figure out something there.
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tnky03
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# Posted: 23 Jun 2013 20:33
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Quoting: ICC The charge controller and other electronics should be kept away from the inverter. In particular do not mount electronics above the batteries.
Our batteries will be in a box outdoors with wires coming into cabin, so then it should be ok to mount charge controller, inverter on the wall, I'm guessing. Thanks for the help, wish better news on fridge, lol. We'll have to figure out something there. We have a really good propane fridge in our motorhome, but it would be very heavy to move and we are afraid that in moving it something might happen and it would no longer work. We really can't afford to buy another propane fridge as they are so expensive.
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ICC
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# Posted: 23 Jun 2013 22:11
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Quoting: tnky03 We have a really good propane fridge in our motorhome, but it would be very heavy to move and we are afraid that in moving it something might happen and it would no longer work. We really can't afford to buy another propane fridge as they are so expensive.
Your RV fridge moves whenever the RV is driven LOL 
Seriously though they can be moved with relative ease with a helper. I've done it. If during the removal and moving they are laid on their side or back all they need is to be left in the right-side -up vertical position for a minimum 24 hours before lighting the burner or connecting to a power source. There are plenty of tubing that must not be damaged but short of dropping it that should not be a problem.
In the RV it is vented to the outside. It would be best to duplicate that in the cabin but that takes some work and is not absolutely necessary. Though if vented inside it will add heat to the cabin interior.
If it is a newer RV fridge it will use a sometimes surprising amount of 12 VDC power. Check the user manual.
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tnky03
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# Posted: 24 Jun 2013 08:52
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Thanks, ICC. We discussed the fridge last night and will probably move it to the cabin when kitchen area is ready. It is in an older,88' Georgie Boy. The brand is Dometic and it works wonderfully. My only problem with it is having to defrost, LOL. That's just one of the small things to deal with in living off-grid I suppose. We do plan to vent it outside, as I am leery of the fumes. With our wiring plan to use an inverter to convert dc-ac will we need to run a dedicated dc wire for the fridge? I know it works off ac/dc/and propane but don't know if it should be run on power through the inverter or directly off dc. I know there are lots of questions but it sure great to have a site we can turn to for answers.
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ICC
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# Posted: 24 Jun 2013 11:58
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even a new propane fredge like a Servel needs to be defrosted manually
AC/DC/Propane. both AC and DC electric operation is by using a resistance heater element. This is ok on grid AC but will quickly deplete a battery if the DC option is used. Using AC thru the inverter is just as bad. So in effect the fridge is propane only when you go off grid. That is the older fridges I am familiar with use no DC or AC for operating with the selector set to Gas. Maybe 12 VDC if there is a light in the fridge. Newer fridges use 12 VDC for the controller board but I don't think they had those back in '88. Those have led or lcd displays usually. If you light a standing pilot with a match or a piezo clicker it should not need any power except for any inside light.
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Rossman
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# Posted: 24 Jun 2013 12:30
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I thought I read a thread on here just the other day about someone who looked at off-grid propane fridges and just decided to go with an modern energy star "standard" fridge as they are quite energy efficient and wasn't worth the hassle of a gas fridge...
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ICC
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# Posted: 24 Jun 2013 14:08
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Last time I had a good look at the energy star atings for smallish fridges i seem to recall that the best in the 10-12 cu ft range were rated at about 300 kWh a year. It is a big long list so i don't feel like going through it again myself. But it can be found at EnergyStar
If there are any fridges, 10 cu ft or so that can substantially beat the 200 kWh a year that may change the picture. Buying extra panels gets cheaper every day but the bugaboo is the storage; batteries are still costly when you need storage that will carry the fridge over a cloudy spell if the place is left unoccupied, but the fridge has food in it. 300 a year is still 820 watt-hours a day.
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MJW
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# Posted: 24 Jun 2013 14:53
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Quoting: Rossman I thought I read a thread on here just the other day about someone who looked at off-grid propane fridges and just decided to go with an modern energy star "standard" fridge as they are quite energy efficient and wasn't worth the hassle of a gas fridge...
That would be me...
Yes, we went with a 14 cf Frigidaire that uses around 350 kwh a year.
It was the best choice for us but might not be for everyone.
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tnky03
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# Posted: 26 Jun 2013 16:03
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MJW, how many panels/batteries do you have? I would love to go that route but everything I read sounds like it would not be very feasible for us.
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MJW
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# Posted: 26 Jun 2013 16:28
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tnky03, right now we are running with only generator power until we get our solar array up and running.
We run our entire house on one Honda EU2000i. Lights, fans, fridge, chest freezer and shallow well pump water holding tanks. We run it for 12 - 14 hours a day using only 1 1/2 gallons of gas and the fridge and freezer both hold their temps just fine.
When we need the AC for a few hours in the hottest part of the day we add the other Honda on and run it.
Our solar set up plan includes 10 panels and either 6 or 8 batteries. Can't remember which right now. It will generate over 10 kwhs a day and the price on it is a tad over 10k.
I would love to get it set up right now but there are other things we want to get done first and we are actually doing well on the generators right now. Besides, the price on solar is dropping every day it seems. I am betting our installation will be cheaper than the quote when we finally get it installed.
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tnky03
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# Posted: 27 Jun 2013 10:15
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Thanks for the info, MJW. I didn't realize a generator would run that long on so little gas, not bad. That will be a must for us to have for extended cloudy periods. You have quite a system there! We will have a far smaller system to work with but have learned to live with minimal power usage already so I'm sure will be fine. I'm not certain just what we'll do fridge wise but most likely will stick with our propane as it is good sized and really meets our needs.
our Dometic Royale propane fridge
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creeky
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# Posted: 28 Jun 2013 09:34
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I got tired of hauling propane ... and the cost.
So I bought a 10 cu ft fridge/freezer with a rating of 312/yr. I have a 1 kw solar system with 1200 amp hrs of battery reserve (@12v).
This system works admirably as long as the sun is shining. So far (2 months?) I've run the generator for an hour or two twice to give my batteries a bit of a bulk charge assist. It'll be a different story come nov/dec, but for now it's all good.
Highly recommended.
For a fridge I would recommend a 24v system with 800 amp hr capacity (1600@12v). 1 kw of panels should still be adequate. But what the heck. Another 500 watts would be useful to run a small air conditioner in the late afternoon.
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