Using Grid-tie panels in off-grid applications & chest freezer faulting all my inverters

WMH Cheryl
WMH Cheryl Registered Users Posts: 17 ✭
in Solar Beginners Corner #1
I have an entire set of grid tie PV panels, inverter, disconnects, etc (about 3800 watts of panels = Sharp 167 watt with a Frontus IG 4000 inverter). After doing some research I am pretty sure I can't use the Frontus inverter (at least not easily and I will never need an "entire" system set up anyway). I have small solar set-ups around the ranch for running electric fences or lights in tackroom, tool shed, well pump (with one Sharp panel direct connected), etc. But all of these have been using one 15 watt panel, small baby charge controller, deep cycle or gell batt, with or without inverter depending on application.

I recently purchased a new 45amp charge controller since the panels are around 22vdc and about 7.8amps each. My plan to run an ozone water purification system on one of my storage tanks was to parallel three of the panels to maintain the 22v (to charge a 12v batt) but increase the amps to the batts. I did not purchase a MPPT charge controller due to the increased price since I already have so many panels sitting around doing nothing. These Sharps panels have two wires each with plugs. I planned on just cutting off the plugs and then wire nutting the 3 wires together (two sets of 3) with the new wire to the disconnect switch that then connects to the new charge controller. But in a recent post I read about some type of solar array combiner. In reading some of the info pages on the NAWS website it sounds like I shouldn't have to worry about an array combiner since the 3-4 panels are really just one array right? Is cutting off the plugs and wirenutting them together "WRONG" ???? The disconnect box I bought appears to just have one set of incoming terminals and one set of outgoing terminals hence why I was just going to wirenut it all together with the larger guage wire to the disconnect that is rated for the 45amp charge controller. Will my jerry-rigged plan not work?

My second problem is yesterday I attempted to connect a new 7.2 cubic foot chest freezer to an inverter/batt. I "thought" I was being smart by filling it up with water bottles and then letting my big generator get it cold for a couple of hours. Before I purchased it, we plugged it into my amp/watt meter thing and I was thrilled to see that it was only pulling 163 watts at start up and then slowly dropping. Of course I initially tried a 200/400 watt inverter which faulted. Then my 400/800 inverter = faulted. Even my 600/1200 watt inverter faulted. In reading some of the other info on this forum and NAWS I realize that my amp/watt meter thing was probably not sensitive enough to catch that very quick initial one or two second surge. So I assume I am now stuck having to buy a larger inverter (1000+ watts) that will cover that super brief surge. But I hate that the inverter will be "wasting" so much power when providing the small draw for the rest of the time. Is there no way around this? Yes I know that a DC frig is the answer but I can't afford a $800-$1000 chest freezer (I paid $80 for the AC chest freezer).

Are there smarter and more "intelligent" and less wasteful inverters out there that can manage the quick surge and then reduce their "energy wasting" ? Since I obviously have to purchase another inverter now (I was so hoping I could get by with what I already own), then I want to make sure I get the best inverter to run just this one item. The reason I worry about using a large inverter to run a small load is because of the energy waste/inefficiency. Just running the 600/1200 watt inverter pulled a volt out of the battery (with no load on inverter).

Thanks for any input and sorry to make some of you super technical guys bang your head against your desk. Yes I know I "jerry-rig" things and do things very cheaply, but with things heating up I really dream about having some type of refrigeration at the ranch and I hate wasting money on ice if I can use "free" sun and all these panels sitting around in storage.

Anyone know what kind of power those electric ice makers pull? If they don't have a "surge" maybe I can just make ice a few times a day and fill the ice chest - ugh.... LOL.

Thanks -
Cheryl
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Comments

  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    #2
    Re: Using Grid-tie panels in off-grid applications & chest freezer faulting all my inver

    Okay stop - before you make any more mistakes.

    The panels at "22 Volts" is probably Voc, not Vmp (what they provide under load). You should be able to get full specs off these: Vmp, Imp, Voc, and Isc. It will help a lot in guiding you if we have this information.

    Next, do not cut off the connectors on the panels and wire-nut them together. Wire-nut connections are not suitable for outdoors anywhere in the world; they will corrode. Furthermore when you parallel more than two panels you should have a fuse or breaker on each panel. This is what an array combiner is; it does not connect two arrays, it connects multiple panels or strings of panels into one array to feed a single charge controller.

    I'm not surprised about your experience with trying to run the freezer; you probably do not have a meter capable of measuring the surge demand as it takes only a fraction of a second - just long enough to fault an inverter that can't supply the power. Most refrigerators demand about 5X their running current in that brief moment. It is not the inverter that is inefficient, it is the refrigerator and there aren't any better AC choices in that department.

    When you size an off-grid system you have to have enough battery to supply the Watt hours over time; too small a battery may run the load, but not for very long.

    With 3800 Watts of panels available I'm sure we can come up with some practical use for them.
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  • waynefromnscanada
    waynefromnscanada Solar Expert Posts: 3,009 ✭✭✭✭
    #3
    Re: Using Grid-tie panels in off-grid applications & chest freezer faulting all my inver
    WMH Cheryl wrote: »

    My second problem is yesterday I attempted to connect a new 7.2 cubic foot chest freezer to an inverter/batt. I "thought" I was being smart by filling it up with water bottles and then letting my big generator get it cold for a couple of hours. Before I purchased it, we plugged it into my amp/watt meter thing and I was thrilled to see that it was only pulling 163 watts at start up and then slowly dropping. Of course I initially tried a 200/400 watt inverter which faulted. Then my 400/800 inverter = faulted. Even my 600/1200 watt inverter faulted. In reading some of the other info on this forum and NAWS I realize that my amp/watt meter thing was probably not sensitive enough to catch that very quick initial one or two second surge. So I assume I am now stuck having to buy a larger inverter (1000+ watts) that will cover that super brief surge. But I hate that the inverter will be "wasting" so much power when providing the small draw for the rest of the time. Is there no way around this? Yes I know that a DC frig is the answer but I can't afford a $800-$1000 chest freezer (I paid $80 for the AC chest freezer).

    Are there smarter and more "intelligent" and less wasteful inverters out there that can manage the quick surge and then reduce their "energy wasting" ? Since I obviously have to purchase another inverter now (I was so hoping I could get by with what I already own), then I want to make sure I get the best inverter to run just this one item. The reason I worry about using a large inverter to run a small load is because of the energy waste/inefficiency. Just running the 600/1200 watt inverter pulled a volt out of the battery (with no load on inverter).

    Thanks for any input and sorry to make some of you super technical guys bang your head against your desk. Yes I know I "jerry-rig" things and do things very cheaply, but with things heating up I really dream about having some type of refrigeration at the ranch and I hate wasting money on ice if I can use "free" sun and all these panels sitting around in storage.

    Anyone know what kind of power those electric ice makers pull? If they don't have a "surge" maybe I can just make ice a few times a day and fill the ice chest - ugh.... LOL.

    Thanks -
    Cheryl

    I definitely would not expect the smaller inverters to start the freezer, but the biggest inverter I would expect would start it IF the battery is strong enough to supply the required surge without dropping it's voltage enough to "fault" the inverter due to low battery voltage.
    By the way, after the freezer has been running a couple of minutes, how much power does your meter suggest it's "pulling"? A good, energy efficient 7.2 cu ft freezer should be hanging around 100 watts or less while running.
    I wouldn't be surprised if the freezer has a start surge of well over 1000 watts, but for a time too short for your meter to register. 1000 watts/12 volts= 83 amps from the battery, NOT including any of the normal losses. A weak or too small a battery cannot supply that without a voltage drop below the inverter Low Voltage shut down point.
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  • zoneblue
    zoneblue Solar Expert Posts: 1,220 ✭✭✭✭
    #4
    Re: Using Grid-tie panels in off-grid applications & chest freezer faulting all my inver

    Ok, you dont say too much about what your experience is, of what your overall plan of attack is. Trying this and trying that, learning as you go. Add a few weeks of reading here, and you will be an expert ;)

    Youve rolled a few ideas into your post, but if you want we can look at a design for the 3.8kWp PV. Or you could also look at some smaller designs, if you dont need all that power.

    Yes that GT inverter is of next to no use to you. It is possible to use GT inverters off grid but only in advanced, (read expensive, multiple inverter), setups. So... ebay?

    Next, i would really caution against messing around with a bunch of cheap chinese inverters. That is not a path to long term happiness, or in particular safety. The products themselves are built with next to no quality control and the failure rate is very high. Thats why theres no brand names. Then, wiring them up correctly is pretty much the domain of an electrician. Yes you can learn to do it correctly yourself, but i would still advise getting an electrician to sign off the AC side of any DIY install. Electricity can kill, and it can burn your house down. Standard disclaimer!

    You might be able to find second hand DC appliances, they tend to come up from time to time, especially stuff from the RV/marine world.

    Now the controller and inverter. Its a sad but true fact that in the world of inverters in particular that you get what you pay for. Once you go past the 75 dollar ebay specials, you get into the serious world of real off grid UL listed inverters., ones designed and built to be installed in houses. The price takes this almighty jump up to around 1200 dollars, and unfortunately theres almost nothing in between those two worlds. One lot is suitable to run a laptop or power tool in the car from time to time, and other suitable for hardwiring into a home to run 24/7.

    The only real compromise is the likes of Xantrex Prosine, and Samlex/Cotek, Powermaster etc. These run less than $1000, and while not having much in the way of features, are robust and safe. Again if money is an issue checkout craigs list etc. People upgrade and onsell them.

    For the charge controller, you have quite a few options, and this will really depend on what you are trying to achieve, system size, distance, budget etc.

    Batterys, learner bank is good. T105 'golf carts', newish ex telco maybe fine, but avoid car/truck/marine faux "deep cycle", really old batterys, hand me downs and such. That will 9 times out 10 only lead to frustration.

    But above all else you need a plan. You have plenty of PV, so sit down figure out whats a suitable size system to aim for, mid to longish term, (even if you build it in stages), and then we can start to look at fitting the pieces of the jigsaw into place.

    But again from the adventures your having, id would caution against too much more trial and error. There lie sharks.
    1.8kWp CSUN, 10kWh AGM, Midnite Classic 150, Outback VFX3024E,
    http://zoneblue.org/cms/page.php?view=off-grid-solar


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  • WMH Cheryl
    WMH Cheryl Registered Users Posts: 17 ✭
    #5
    Re: Using Grid-tie panels in off-grid applications & chest freezer faulting all my inver

    Hmmmm...... Wayne I had not realized that a weak battery might cause the inverter to fault/alarm also. It is a 98 AH gell cell (used, previously in an electric car) and I knew it wasn't at full charge since it had been a couple of months since I had a solar panel charge it. It read 12.8 volts but dropped to 11.8 volts with the 600/1200 watt inverter running on it for about 10 minutes (with no load/nothing plugged into the inverter). I have that batt and a couple others hooked up to solar panels now to charge so I will test one last time with the 600/1200 watt inverter tomorrow.

    Cariboocoot I will go get the specs off the panels tonight when I am back at the ranch. Do Grid tie systems have Array combiners? Maybe I already have one in all the stuff from the old gridtie system? I thought the other electric boxes were like disconnects or something. This was formerly a N. CA PG&E approved installation so it has all the extra stuff they required. I figured if I heat shrink wrapped the wire nut connections (or even used the underwater type connectors like used in my wells) that I wouldn't have to worry about weather that much. The connections will be under the panels and be protected from sun/rain/wind, etc. But I guess that is a big no go. I warned you that you would be beating your head on your desk with my jerry rigged ideas.
    Zoneblue - thanks for the info about inverters. Geez with the price of the good ones then I would probably be better off just buying the type of DC frig that can have a panel direct connected to it. I will also check out craigslist. I didn't think to look there for inverters. I don't want to go the route of a propane frig because I don't want to shell out money all the time to purchase propane. Hence trying to use solar panels. The biggest drawback for long term use of solar is the batteries which I have had nightmares with over the years. That is why when I can I try to avoid using batts (like my well pump is direct to solar panel, so easy, I LOVE it). I don't really want to design a "system". Right now I get along fine with my baby solar stuff all over the ranch. I don't want to have to spend big bucks in cable to run power all over the place. So far cheaper for me over the years to set up mini solar stuff in each location. Right now I mainly use solar flashlight, lanterns, etc. All charge from sun or DC lighter charger which I just plug in when I drive the truck into town, etc. (Same with laptop, tablet, cell phone, etc). So my only real "fantasy" has been to have refrigeration or freezing capability. During winter things keep cool outside just fine. But temps getting up to the 80's the last couple of days and since I no longer have a refrig/freezer within 5 miles of the ranch to use, I hate having to drive all the way into town to purchase ice and not be able to stock food or cold sodas.

    Thanks for the input. I will get more specific data on the panels. But not really sure why I have to worry about that since I will be using the panels to only charge a 12 volt system and I am pretty sure that a 22v panel can handle charging a 12v battery.
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  • bill von novak
    bill von novak Solar Expert Posts: 891 ✭✭✭✭
    #6
    Re: Using Grid-tie panels in off-grid applications & chest freezer faulting all my inver
    WMH Cheryl wrote: »
    Hmmmm...... Wayne I had not realized that a weak battery might cause the inverter to fault/alarm also. It is a 98 AH gell cell (used, previously in an electric car) and I knew it wasn't at full charge since it had been a couple of months since I had a solar panel charge it. It read 12.8 volts but dropped to 11.8 volts with the 600/1200 watt inverter running on it for about 10 minutes . . . .
    That's one of the first things to look at. A LARGE capacitor (we are talking many farads) across the battery might help; a better battery definitely would. If you have an oscilloscope (even a multimeter with a scope function; they're not expensive) then that will tell you definitively whether you are getting dropout in DC voltage due to start surge.
    Do Grid tie systems have Array combiners?
    Rarely, since most are high voltage string systems with one, maybe two, strings. (And even then many GT inverters have inputs for more than one string.)
    I figured if I heat shrink wrapped the wire nut connections (or even used the underwater type connectors like used in my wells) that I wouldn't have to worry about weather that much. The connections will be under the panels and be protected from sun/rain/wind, etc. But I guess that is a big no go.
    Not really. UV-proof shrink wrap with sealant over soldered connections might work, but wire nuts aren't going to get you there. MC connectors aren't all that expensive; why not just get a bunch off Ebay?
    That is why when I can I try to avoid using batts (like my well pump is direct to solar panel, so easy, I LOVE it). I don't really want to design a "system".
    Well, your solar power system will never be better than your system design, so decide how much reliability/capability you want.
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  • WMH Cheryl
    WMH Cheryl Registered Users Posts: 17 ✭
    #7
    Re: Using Grid-tie panels in off-grid applications & chest freezer faulting all my inver

    Samlex 12v 1000 Watt Pure Sine Wave Inverter SSW-1000-12A

    These inverters look affordable. It "claims" that it can surge to 2000 watts ???? NASW has them on sale. I thought Pure Sine Wave was the way to go and should be more pricey. So what am I missing since this inverter seems quite affordable ??????
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  • bill von novak
    bill von novak Solar Expert Posts: 891 ✭✭✭✭
    #8
    Re: Using Grid-tie panels in off-grid applications & chest freezer faulting all my inver
    WMH Cheryl wrote: »
    These inverters look affordable. It "claims" that it can surge to 2000 watts ???? NASW has them on sale. I thought Pure Sine Wave was the way to go and should be more pricey. So what am I missing since this inverter seems quite affordable ??????

    A few things. One, I noticed this: "2,000 Watts (<3 seconds at Power Factor 1)" That means that it can supply 2000 watts into a purely resistive load. A motor during startup is a very reactive load. So you may not see that much available power. Two, 2000 watts at 12 volts is 166 amps. That will cause the battery voltage to sag. If it sags to say 10.5 volts now you are drawing 190 amps. Below 10.5 volts the inverter shuts down. It doesn't take much resistance at all (only 7 milliohms) to cause that much voltage drop.
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  • WMH Cheryl
    WMH Cheryl Registered Users Posts: 17 ✭
    #9
    Re: Using Grid-tie panels in off-grid applications & chest freezer faulting all my inver
    bill von novak wrote: »
    MC connectors aren't all that expensive; why not just get a bunch off Ebay?

    I had to google what an MC connector was - LOL..... the panels currently have similar connectors but I am guessing (without looking at them at the moment) that since they were originally a grid tie type panel, that the connectors are set up to be in series since the goal was to combine the voltages to get up to two strings/arrays for a total of 240 volt. That is why I was thinking I had to cut the current connectors off so I can hook up in parallel instead of in series.

    I will also research to see if they have some type of adapters for the current Sharp panel connectors so they can hook up in parallel.
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  • WillBkool
    WillBkool Solar Expert Posts: 35 ✭✭
    #10
    Re: Using Grid-tie panels in off-grid applications & chest freezer faulting all my inver

    Hi, welcome to the exciting world of Solar! Depending on how old your panels are, they might have MC3 or MC4 connectors. I have both, so I had to buy an adapter.

    I'm not sure on the SSW series from Samlex, the PST and SA generally get good reviews. With all of those panels, you should probably go for a 24 or 48 volt system. Don't buy anything else until you figure out what you need, and the guys here can help.
    1220 Watts, 4 Evergreen 120 watt, 1 Eoplly 190 watt; 1 Sungold 200 watt; 2 175 Watt; M-Star 15A MPPT; C40 PWM; 6 105 AH AGM Configured to 315@24V
    Cotek 1500 watt/24v
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  • solar_dave
    solar_dave Solar Expert Posts: 2,397 ✭✭✭✭
    #11
    Re: Using Grid-tie panels in off-grid applications & chest freezer faulting all my inver

    You just buy MC4 extension cables and cut them in half for your bare wire needs,
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  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    #12
    Re: Using Grid-tie panels in off-grid applications & chest freezer faulting all my inver

    Okay Cheryl is being drowned in information and some of it isn't good.

    Never mind putting capacitors across batteries for power inverters.
    Never mind buying inverters at random no matter what country they come from.

    You need facts to deal with, and one of those facts has to be the answer: what are you trying to do?
    Run a refrigerator. Fine. Now we know how much the refrigerator draws while running: 167 Watts max. We also know from calculating that the start surge is going to be over 1kW, probably well over that.
    You should not be looking at 12 Volt systems here. There is no point in using 12 VDC unless you have no choice in the matter. Go for 24 Volts now and save yourself some trouble. One possible inverter is the Samlex SA-2000-124K: http://www.solar-electric.com/sa2wa24vosiw.html It will run a refrigerator. It does not have a built-in AC charger for recharging batteries from the generator when the sun doesn't shine.

    Next is the question of how much power the 'frige uses over time. This will vary with factors such as weather and how often the door is opened. Usually a 1/3 duty cycle is normal, so that 167 Watts (always go with the maximum; better to have too much power than too little) times 8 hours or 1336 Watt hours. So basically you're trying to come up with 2kW hours, not unusual or difficult for a 24 Volt system as even with the conversion efficiency and inverter consumption you are looking at using less than 100 Amp hours @ 24 Volts.

    To get that at 50% DOD all you'd need is standard GC2's; the cheapest Watt hour deal in batteries going. Four in series gives you 220 Amp hours @ 24 Volts and a capacity up to 2.6kW hours.

    To recharge that you need 22 Amps @ 24 Volts. That's a 770 Watt array on a PWM controller or 686 Watts on an MPPT controller. You could go larger, and should if you're planning on 50% DOD. Up to twice those numbers in fact (you can have a peak charge current of 20% on flooded cells and you'll probably never see it due to the nature of charging from solar).

    The panels you have are 167 Watt probably ND167U1 which are an odd GT style panels with Vmp 23.5 Imp 7.1 (yes, I looked them up). This means you would need two in series on a 24 Volt system because the Vmp is too low. It also means you should use an MPPT charger with them for any system because the Vmp is 'odd' and they won't work efficiently without one. I would go with eight of these panels, meaning four parallel strings of two in series. That's 1336 Watts and should provide about 43 Amps peak charge current (19.5%). You could reduce this to three strings, or you could go with a larger battery bank.

    I believe you have about twenty-two of these panels, so you'd still have at least fourteen left over. If you want to look at the system size you could design based on utilizing all the panels we can do it that way too.
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  • bill von novak
    bill von novak Solar Expert Posts: 891 ✭✭✭✭
    #13
    Re: Using Grid-tie panels in off-grid applications & chest freezer faulting all my inver
    WMH Cheryl wrote: »
    the panels currently have similar connectors but I am guessing (without looking at them at the moment) that since they were originally a grid tie type panel, that the connectors are set up to be in series since the goal was to combine the voltages to get up to two strings/arrays for a total of 240 volt. That is why I was thinking I had to cut the current connectors off so I can hook up in parallel instead of in series.

    You can hook MC cables in parallel as well as in series; they're just wiring connectors. What you do with the other end determines how your system is connected.

    BTW you can't just "wire nut" a bunch of strings in parallel. For a lot of parallel strings you need to put a fuse or circuit breaker on each string for safety reasons.
    I will also research to see if they have some type of adapters for the current Sharp panel connectors so they can hook up in parallel.

    They do, but again, you probably don't want to do that. Many strings in parallel is something of a safety issue.
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  • zoneblue
    zoneblue Solar Expert Posts: 1,220 ✭✭✭✭
    #14
    Re: Using Grid-tie panels in off-grid applications & chest freezer faulting all my inver

    What Coot recomends is sound advice. A fridge is a kind of taskmaster for solar. Once your system is rated for a fridge it takes if from being a toy system to something that can and will run a house. Think of the lights and cell phone chargers, small water pumps etc as being a sort of side bonus of the fridge.

    So: you want a fridge = you need a design. As lots of people in different ways have endevoured to convey above.
    1.8kWp CSUN, 10kWh AGM, Midnite Classic 150, Outback VFX3024E,
    http://zoneblue.org/cms/page.php?view=off-grid-solar


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  • WMH Cheryl
    WMH Cheryl Registered Users Posts: 17 ✭
    #15
    Re: Using Grid-tie panels in off-grid applications & chest freezer faulting all my inver

    Thanks everyone! Coot you are always so helpful, thanks! Since the price of a good and correct inverter and better batts is $1000+, then I will go with a direct connect Sundanzer fridge. I really hate batts and after frying my first one 15 years ago (before learning about charge controllers), I just hate depending on them.

    Will one of my Sharp panels work on the Sundanzer even though it is a strange voltage?

    Thanks again!
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  • vtmaps
    vtmaps Solar Expert Posts: 3,741 ✭✭✭✭
    #16
    Re: Using Grid-tie panels in off-grid applications & chest freezer faulting all my inver
    WMH Cheryl wrote: »
    I will go with a direct connect Sundanzer fridge.
    Take a look at the Steca fridges... same compressor (Danfoss) as the sundanzer, similar price, and more features. The Steca can be a freezer or a fridge, whereas the Sundanzer needs to have its thermostat replaced to convert from fridge to freezer.

    --vtMaps
    4 X 235watt Samsung, Midnite ePanel, Outback VFX3524 FM60 & mate, 4 Interstate L16, trimetric, Honda eu2000i
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  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    #17
    Re: Using Grid-tie panels in off-grid applications & chest freezer faulting all my inver
    WMH Cheryl wrote: »
    Thanks everyone! Coot you are always so helpful, thanks! Since the price of a good and correct inverter and better batts is $1000+, then I will go with a direct connect Sundanzer fridge. I really hate batts and after frying my first one 15 years ago (before learning about charge controllers), I just hate depending on them.

    Will one of my Sharp panels work on the Sundanzer even though it is a strange voltage?

    Thanks again!

    Unless I'm getting confused (again) the Sundanzer is design to run on 12 to 24 Volts so it shouldn't mind Voltage in between.

    The low Vmp problem is one of not having enough 'overhead' for a 24 Volt system (after losses the Voltage reaching the battery is too low to charge it).

    Most people's problem with batteries is from bad advice. That is they don't read this forum. ;)
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  • WMH Cheryl
    WMH Cheryl Registered Users Posts: 17 ✭
    #18
    Re: Using Grid-tie panels in off-grid applications & chest freezer faulting all my inver

    Specific panel info:

    Sharp ND-167U3A. Pmax 167.0 watts
    VOC. 28.9 v
    Isc. 8.16 A
    Vpmax. 22.8 v
    Ipmax. 7.33 A
    Max system voltage 600 v
    Fuse rating 15 A

    Charge controller I purchased to use with these panels = TriStar TS-45. (45 amps)
    I didn't spend the extra money for a MPPT controller since I have so many extra panels.

    Do you think the 22.8 volts will play havoc with the Sundanzer?
    They say 12-24 volt input ???
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  • WMH Cheryl
    WMH Cheryl Registered Users Posts: 17 ✭
    #19
    Re: Using Grid-tie panels in off-grid applications & chest freezer faulting all my inver
    Cariboocoot wrote: »

    Most people's problem with batteries is from bad advice. That is they don't read this forum. ;)

    Actually my problem is that I am terrible about maintenance. I abuse the heck out of my equipment. I have about 13 batts I am dealing with now and surely don't want more.
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  • WMH Cheryl
    WMH Cheryl Registered Users Posts: 17 ✭
    #20
    Re: Using Grid-tie panels in off-grid applications & chest freezer faulting all my inver
    vtmaps wrote: »
    Take a look at the Steca fridges... same compressor (Danfoss) as the sundanzer, similar price, and more features.
    --vtMaps

    Do you know where they can be purchased? None of the west coast solar stores seem to carry Steca brand???
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  • vtmaps
    vtmaps Solar Expert Posts: 3,741 ✭✭✭✭
    #21
    Re: Using Grid-tie panels in off-grid applications & chest freezer faulting all my inver
    WMH Cheryl wrote: »
    Do you think the 22.8 volts will play havoc with the Sundanzer?
    They say 12-24 volt input ???

    The fridge will never see 22 volts. The fridge will see the battery voltage. The battery will act as a "buffer" so that the panel voltage (which ranges from 0 to 28.9) will never be seen by the fridge.
    WMH Cheryl wrote:
    Do you know where they can be purchased? None of the west coast solar stores seem to carry Steca brand?

    Do a google on "steca refrigerator" and take your pick of retailers.

    by the way, I have a sundanzer freezer. I didn't know about the Steca when I bought it. I have a little bit of buyer's remorse because the Steca looks like it has some features that I would appreciate.

    One negative for the sundanzer is its thermostat. Not only does it need a different thermostat for freeze vs refrigeration, but the thermostat sensor is NOT in the food compartment (I think its on the freon return from the evaporator). This may confer some slight efficiency advantages under normal conditions (normal= freezer in kitchen). However, my freezer is in an outbuilding which may experience near freezing conditions. This should give me very low energy usage, but it screws up the sundanzer. According to the sundanzer manual, the sundanzer does not work reliably when its ambient temperature is near the food compartment temperature. I can confirm that.

    --vtMaps
    4 X 235watt Samsung, Midnite ePanel, Outback VFX3524 FM60 & mate, 4 Interstate L16, trimetric, Honda eu2000i
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  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    #22
    Re: Using Grid-tie panels in off-grid applications & chest freezer faulting all my inver

    For some reason I thought she was referring to the 'frige that runs directly from panels, no batteries involved.

    Personally I have nothing against batteries. :D
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