240 vs 120 volt inverters
verdigo
Solar Expert Posts: 428 ✭✭
I have been eyeballing Magnum's 4448PAE 4400 watt 120/240 volt inverter/charger. Its pretty pricey but will save money on the purchase of a separate battery charger for those cloudy days/weeks. My battery bank will be 232 ah at 48 volts. My solar array will be 8 280 watt panels connected to a Classic 150 charge controller. My current loads are a nightmare for the size of the house. I plan on using a Reliance 6 circuit generator transfer switch panel to power selected 120 volt circuits. The Reliance unit also has a 240 volt service which can be used with this inverter to give me more flexibility to use the existing AC breaker box to power more circuits if need be. If anyone sees any gaping holes in my plan I would appreciate your input. Electricity is cheap and reliable here and I could do nothing at all and get by on my little 2.5 k Honda generator during an outage, but that wouldn't be much fun.
Dennis
Dennis
Comments
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Re: 240 vs 120 volt inverters
What have you got for 240 VAC loads?
If nothing you may not need it on the supply side. But if it makes the wiring easier it's about the same cost as a 120 VAC inverter of the same size.
If you have electric hot water a 4kW inverter will just about handle that. An electric stove will probably shut it down (one burner would work, turn on a second and it could fault). Remember the 120 VAC loads will be pulling on it too.
Otherwise you've got about a 2kW array, plenty for 232 Amp hours @ 48 Volts (36 Amps or so output). Battery bank might be a tad small for the inverter/panels/loads.
Can't say I see anything major wrong with the plan at all.
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Re: 240 vs 120 volt inverters
What are your loads like? And are you planning on doubling the battery bank capacity sometime in the future?
Your battery bank would be a good fit for ~2,400 watt max continuous loads and ~4.8kW peak surge current (starting well pump, etc.). A 4.4 kW inverter is a tad on the "large side" for this installation as is.
Check the AC Inverter's standby current (on and no loads, in search mode, etc.). Sometimes the larger inverters can take a relatively large amount of idle current/be fairly inefficient at light loads (if price/performance otherwise meets your needs--go for it).
-BillNear San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset -
Re: 240 vs 120 volt inverters
I was wondering about the battery bank. Would I need to ad more panels if I doubled the battery bank? Also how much use could I put on the battery bank before causing problems by adding another? -
Re: 240 vs 120 volt invertersI was wondering about the battery bank. Would I need to ad more panels if I doubled the battery bank? Also how much use could I put on the battery bank before causing problems by adding another?
Double the battery bank would be 464 Amp hours (let me guess: East Penn PS2200?). You can expect about 36 Amps max from the array using an MPPT controller so that's a charge rate of (36 * 100 /464) 7.7%. That is in the "marginal" category, because loads may draw enough to reduce that effective charge rate to below the 5% recommended minimum. So it would depend on how your system actually gets used.
I know: "thanks for the non-answer."
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Re: 240 vs 120 volt invertersCariboocoot wrote: »What have you got for 240 VAC loads?
If nothing you may not need it on the supply side. But if it makes the wiring easier it's about the same cost as a 120 VAC inverter of the same size.
If you have electric hot water a 4kW inverter will just about handle that. An electric stove will probably shut it down (one burner would work, turn on a second and it could fault). Remember the 120 VAC loads will be pulling on it too.
Otherwise you've got about a 2kW array, plenty for 232 Amp hours @ 48 Volts (36 Amps or so output). Battery bank might be a tad small for the inverter/panels/loads.
Can't say I see anything major wrong with the plan at all.
Everything is electric. Water heater, stove, dryer, radiant wall heaters with fans, and a rather large window A/C unit. -
Re: 240 vs 120 volt invertersCariboocoot wrote: »Double the battery bank would be 464 Amp hours (let me guess: East Penn PS2200?). You can expect about 36 Amps max from the array using an MPPT controller so that's a charge rate of (36 * 100 /464) 7.7%. That is in the "marginal" category, because loads may draw enough to reduce that effective charge rate to below the 5% recommended minimum. So it would depend on how your system actually gets used.
I know: "thanks for the non-answer."
Thats ok. I know it would have to be managed. Just can't run everything at once, or on the same days. -
Re: 240 vs 120 volt invertersEverything is electric. Water heater, stove, dryer, radiant wall heaters with fans, and a rather large window A/C unit.
Okay, there is a major problem.
When the power goes out and you need to run off batteries that 232 Amp hours will provide about 5kW hours of power and maybe will handle 2 kW draw at any one time.
Everything you listed there will suck that battery bank flat either in an instant from too much current draw or in very short order from the high Watt hour consumption. -
Re: 240 vs 120 volt invertersCariboocoot wrote: »Okay, there is a major problem.
When the power goes out and you need to run off batteries that 232 Amp hours will provide about 5kW hours of power and maybe will handle 2 kW draw at any one time.
Everything you listed there will suck that battery bank flat either in an instant from too much current draw or in very short order from the high Watt hour consumption.
Well I probably won't be running heat and A/C at the same time. I do have a solar clothes dryer, and a Coleman stove. I am gonna take your advice on the additional batteries though. Do you think I need a couple more panels? -
Re: 240 vs 120 volt invertersWell I probably won't be running heat and A/C at the same time. I do have a solar clothes dryer, and a Coleman stove. I am gonna take your advice on the additional batteries though. Do you think I need a couple more panels?
If it were me I'd make the most of solar that I could: panel prices are pretty low right now. Boosting the battery capacity up to 464 and then trying for 10% peak charge rate (even more if you can afford it) will give you more panel power for load running during daylight, if you can use the power at that time. If the majority of your power usage is "after sunset" the surplus panel won't do you any good because the daily power is coming mainly from batteries.
What I'd usually call for: 464 Amp hours with DOD of 25% (about 5.5 kW hours daily) and 2800 to 3000 Watts of panel. If you can use lots of power during the day you could increase the array even further. Around 4kW. -
Re: 240 vs 120 volt invertersEverything is electric. Water heater, stove, dryer, radiant wall heaters with fans, and a rather large window A/C unit.
Yeah, the Magnum won't run most of that stuff even if you had a big battery bank on it. We have Trane Central AC, electric water heating, electric induction/convection range, electric dryer - all off-grid. And I can say from experience that it takes either a really big inverter with a big battery bank, or an inverter with generator support capability to even run the oven in the range with any other normal loads on. The Magnum don't have gen support, and it ain't big enough to even flip the switch on the range - even if you did have a big battery bank on it.
Your water heater probably has 4,500 watt elements in it. The Magnum won't run that either with other normal loads on. I swapped out the standard 4,500's in our two 55 gallon heaters with 2,000's to reduce the load on the inverter during water heating. It takes longer to heat the water (that's why we have two 55 gallon heaters to store more reserve from "good" days). But then the inverter can handle it with the smaller elements.
120V inverters don't have any problems with leg balancing. Split phase inverters do. So it's possible (and not really even that hard) to leg overload a split phase inverter with normal 120V loads too. So basically, I see no reason to buy a split phase inverter unless you buy a more capable one with gen support if you want to run your 240V stuff with off-grid power. The Magnums are fine for off-grid people who need to run a 240V well pump and don't want to use a transformer on a 120V inverter. But they are woefully inadequate for handling any real 240V loads beyond that.
Just my 2 cents.
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Chris -
Re: 240 vs 120 volt inverters
For what it's worth you can parallel two Magnums. But then cost wise you're better off buying a Radian or XW6048. -
Re: 240 vs 120 volt invertersCariboocoot wrote: »For what it's worth you can parallel two Magnums. But then cost wise you're better off buying a Radian or XW6048.
Outback has another split-phase system too that has two inverters stacked on one panel - can't remember the name of it. But it don't have gen support capability, so you still got a nightmare trying to run heavy 240V loads with off-grid power. Most people can't afford the batteries it takes to run one of those big inverters at Full Dawg.
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Chris -
Re: 240 vs 120 volt inverters
Yeah. Two more panels and I would be at 2800. Just have to find a place to mount them. For the time being I have room for 8. I think two strings of eight batteries is a good idea if I can keep them charged up.Cariboocoot wrote: »If it were me I'd make the most of solar that I could: panel prices are pretty low right now. Boosting the battery capacity up to 464 and then trying for 10% peak charge rate (even more if you can afford it) will give you more panel power for load running during daylight, if you can use the power at that time. If the majority of your power usage is "after sunset" the surplus panel won't do you any good because the daily power is coming mainly from batteries.
What I'd usually call for: 464 Amp hours with DOD of 25% (about 5.5 kW hours daily) and 2800 to 3000 Watts of panel. If you can use lots of power during the day you could increase the array even further. Around 4kW. -
Re: 240 vs 120 volt invertersCariboocoot wrote: »For what it's worth you can parallel two Magnums. But then cost wise you're better off buying a Radian or XW6048.
Took a look at the XW648 on the store site. Its rated at about 1.5 times the Magnum's output. Two Magnums would be more inverter and I could spread the cost out over time. Gonna have to think on that a bit. -
Re: 240 vs 120 volt invertersChrisOlson wrote: »Yeah, the Magnum won't run most of that stuff even if you had a big battery bank on it. We have Trane Central AC, electric water heating, electric induction/convection range, electric dryer - all off-grid. And I can say from experience that it takes either a really big inverter with a big battery bank, or an inverter with generator support capability to even run the oven in the range with any other normal loads on. The Magnum don't have gen support, and it ain't big enough to even flip the switch on the range - even if you did have a big battery bank on it.
Your water heater probably has 4,500 watt elements in it. The Magnum won't run that either with other normal loads on. I swapped out the standard 4,500's in our two 55 gallon heaters with 2,000's to reduce the load on the inverter during water heating. It takes longer to heat the water (that's why we have two 55 gallon heaters to store more reserve from "good" days). But then the inverter can handle it with the smaller elements.
120V inverters don't have any problems with leg balancing. Split phase inverters do. So it's possible (and not really even that hard) to leg overload a split phase inverter with normal 120V loads too. So basically, I see no reason to buy a split phase inverter unless you buy a more capable one with gen support if you want to run your 240V stuff with off-grid power. The Magnums are fine for off-grid people who need to run a 240V well pump and don't want to use a transformer on a 120V inverter. But they are woefully inadequate for handling any real 240V loads beyond that.
Just my 2 cents.
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Chris
I won't be turning most of 240 stuff on all at once, or I'll leave it on the grid until I build up to it. It would be possible to re-arrange the 120 loads at the breaker box to balance the two legs to some degree, right? -
Re: 240 vs 120 volt invertersIt would be possible to re-arrange the 120 loads at the breaker box to balance the two legs to some degree, right?
To a certain extent you can. It depends on how big the loads are. For instance, let's say you throw a pizza in the microwave and turn it on. Then your wife fires up her hair dryer. A 120V inverter won't have a problem with that. A split phase inverter will if they're both on the same leg. With split-phase, even if you have your loads perfectly balanced, say at 2,000 watts, and you turn on another big 1,500 watt 120V load the inverter goes into leg overload.
We had 120V only for many years with a transformer to run our well. Never had a problem with it. We went to dual 4024's and besides being horribly inefficient running dual inverters we all sorts of problems with leg balancing, no matter what I did in the Main panel. We then put in a single 5548 with a PSX-240 and that worked MUCH better, but was a little underpowered for our loads. So we put in the XW6048 instead and I got the PSX-240 on the distribution panel to keep the inverter and gen leg-balanced
Attachment not found.
While the balancing transformer is not technically needed, it greatly enhances the efficiency of both the generator and inverter at high loadings.
Also, two Magnums are not more inverter than a single XW6048. The efficiency isn't even close and the big XW will handle huge overloads that exceed the rating of both Magnums for a long time before it overheats. The Magnums also have problems with voltage regulation - one of our off-grid neighbors a hike thru the woods here bought a new PAE and they can't even run their washing machine without the lights in the house blinking like a disco. Other folks have noted this problem with them too. The big XW is a beast by comparison. JUST the transformer in a XW weighs more than a whole Magnum inverter. Just sayin'.
Edit:
With the XW you also get Generator Support. The Magnums, stacked or not, don't have it.
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Chris -
Re: 240 vs 120 volt inverters
An XW will also take a 12 kW "hit" and can be stacked. So can a Radian (8kW surge to 16).
Using an autotransformer on the Magnum's output would handle the leg balancing if this is likely to be an issue. Whether or not it is depends on the severity of the imbalance. I believe the trouble spot is actually quite high; around 70% difference.
The real problem here is the number of high Wattage 240 VAC loads on the list. If you could leave them on the grid you'd be better off. Which begs the question of why you are doing this? -
Re: 240 vs 120 volt inverters
I see that you have the grid. It would be lots easier and lower cost to be gridtied. Use a grid tied inverter instead of battery inverter. More efficient and less cost -
Re: 240 vs 120 volt invertersCariboocoot wrote: »The real problem here is the number of high Wattage 240 VAC loads on the list.
Yes! With only 464ah of battery capacity you are only roughly 1/3 of the way to the battery capacity you need to run a 6048 at full load. A 6048 will totally kill your fully charged 464ah bank in less than 30 minutes at full load. That's not enough time to even preheat the oven and make a pizza for supper.
Do NOT underestimate the battery power it takes to run one of these beasts. The specs on the battery tag don't mean diddly when you load two little strings of golf cart batteries with a big inverter. The voltage will sag so bad under load that the inverter will shut down.
However, the huge 240V loads in most homes are intermittent loads, while the average loads are quite reasonable. So there IS a way to run virtually anything you want to run with off-grid power that is efficient, and doesn't cost an arm and leg to do it. And that's with an inverter with Generator Support. Not many people know what this feature does, much less use it. And that's why I did a demonstration once with our old SW Plus system to show what it's all about.
This might be a good time for verdigo, being he has an all-electric home, to review the Generator Support Thread:
http://forum.solar-electric.com/showthread.php?18459-Demonstration-of-Generator-Support
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Chris -
Re: 240 vs 120 volt invertersChrisOlson wrote: »Y
This might be a good time for verdigo, being he has an all-electric home, to review the Generator Support Thread:
http://forum.solar-electric.com/showthread.php?18459-Demonstration-of-Generator-Support
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Chris
The generator support is a nice feature. I could probably get by with the XW4548. That PSX-240 is an interesting piece of equipment as well. Thanks for all the input. -
Re: 240 vs 120 volt invertersCariboocoot wrote: »An XW will also take a 12 kW "hit" and can be stacked. So can a Radian (8kW surge to 16).
Using an autotransformer on the Magnum's output would handle the leg balancing if this is likely to be an issue. Whether or not it is depends on the severity of the imbalance. I believe the trouble spot is actually quite high; around 70% difference.
The real problem here is the number of high Wattage 240 VAC loads on the list. If you could leave them on the grid you'd be better off. Which begs the question of why you are doing this?
I think Chris has me sold on the XW, but I think the XW4548 will suit me. (About the same money as the Magnum) Why am I doing this? I take care of my father who is a shut in. He is tethered to an oxygen concentrator, a dehumidifier, and an air conditioner. Its mainly for back-up power for those items. The other reason is for something to do. Its cheaper than boats and classic cars, which may get used 10 or so times in a year. I have always been a car guy, and any car guy will tell you that more power is better.8) -
Re: 240 vs 120 volt invertersThe generator support is a nice feature. I could probably get by with the XW4548. That PSX-240 is an interesting piece of equipment as well. Thanks for all the input.
I wouldn't select an inverter at random. If you really do want to power these big 240V loads with off-grid power you have to know what they draw, and I'd put an ammeter on them to determine that. The 4548 is going to be bare minimum for the oven in an electric range, for instance, with other normal loads on. Or even the electric clothes dryer - they typically draw more power than the oven in the range even.
With generator support, you can pre-start the generator to run these things so it's there right away when the big load hits and doesn't sack your batteries out before the inverter has time to start the gen, get it warmed up, sync with it, and bring it online. But for full-time off-grid you demand a little convenience because it gets really old, really fast, when you have to constantly baby-sit a power system. So that means auto gen start. It also means a bigger inverter because the inverter has to be able to carry the big load standalone for a certain period of time until it can call for help from the generator.
Basically, with the list of appliances you provided, my experience with it says the 4548 is too small. But you got another problem too - 464ah of battery capacity won't power a 6048 for more than a few minutes at full load. Even from a fully charged state I don't think two strings of golf cart batteries will deliver the required amps for the five minute delay built in to the XW for gen Load Start. The rated amp draw of the 6048 is 130 amps. But that's at 50.4V input. Batteries sag on voltage when you put a big load on them, and that causes the efficiency of the inverter to drop dramatically so the real amp draw with a small bank is going to be closer to 170 amps. And the bank has to maintain that above 44.0 volts at the inverter power studs or it will shut down.
So it's not as simple as looking at an inverter and the specs say "6,000 watts" so you think you can run a 6 kVA load with it with a few batteries. You're going to spend double on the batteries what the inverter costs to even use it at it's full rated capacity. And many people don't realize that fact.
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Chris -
Re: 240 vs 120 volt invertersThat PSX-240 is an interesting piece of equipment as well.
vertigo -
The PSX-240 is an autotransformer. That means it has an identical primary and secondary winding. It can be used to step 120V up to 240V split-phase. It can be wired to step 240V split-phase down to 120V single phase. And it can be wired into a split phase service panel or generator to balance the two legs of the split-phase source.
This is what it looks like inside:
Attachment not found.
I think NAWS sells them for around $400 or so and they weigh in the neighborhood of 40-50 lbs so shipping isn't really cheap either. If you do select a smaller split-phase inverter, I would definitely consider one. It will eliminate a lot of problems for you trying to keep your panel leg-balanced without overloading the inverter when you turn on a big load.
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Chris -
Re: 240 vs 120 volt invertersChrisOlson wrote: »I wouldn't select an inverter at random. If you really do want to power these big 240V loads with off-grid power you have to know what they draw, and I'd put an ammeter on them to determine that. The 4548 is going to be bare minimum for the oven in an electric range, for instance, with other normal loads on. Or even the electric clothes dryer - they typically draw more power than the oven in the range even.
With generator support, you can pre-start the generator to run these things so it's there right away when the big load hits and doesn't sack your batteries out before the inverter has time to start the gen, get it warmed up, sync with it, and bring it online. But for full-time off-grid you demand a little convenience because it gets really old, really fast, when you have to constantly baby-sit a power system. So that means auto gen start. It also means a bigger inverter because the inverter has to be able to carry the big load standalone for a certain period of time until it can call for help from the generator.
Basically, with the list of appliances you provided, my experience with it says the 4548 is too small. But you got another problem too - 464ah of battery capacity won't power a 6048 for more than a few minutes at full load. Even from a fully charged state I don't think two strings of golf cart batteries will deliver the required amps for the five minute delay built in to the XW for gen Load Start. The rated amp draw of the 6048 is 130 amps. But that's at 50.4V input. Batteries sag on voltage when you put a big load on them, and that causes the efficiency of the inverter to drop dramatically so the real amp draw with a small bank is going to be closer to 170 amps. And the bank has to maintain that above 44.0 volts at the inverter power studs or it will shut down.
So it's not as simple as looking at an inverter and the specs say "6,000 watts" so you think you can run a 6 kVA load with it with a few batteries. You're going to spend double on the batteries what the inverter costs to even use it at it's full rated capacity. And many people don't realize that fact.
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Chris
Looks like leaving the stove and clothes dryer on the grid for day to day use is my best option. I can get Interstate GC2-HXD batteries ( http://www.interstatebatteries.com/cs_eStore/content/product_info/golf_f.asp ) for around $100 each through my garage account. For the money the 4548 seems like the way to go to be able to use my larger 240 items with generator support, and keep my battery bank at 464ah?
Thanks for all your help.
Dennis -
Re: 240 vs 120 volt invertersChrisOlson wrote: »vertigo -
The PSX-240 is an autotransformer. That means it has an identical primary and secondary winding. It can be used to step 120V up to 240V split-phase. It can be wired to step 240V split-phase down to 120V single phase. And it can be wired into a split phase service panel or generator to balance the two legs of the split-phase source.
This is what it looks like inside:
Attachment not found.
I think NAWS sells them for around $400 or so and they weigh in the neighborhood of 40-50 lbs so shipping isn't really cheap either. If you do select a smaller split-phase inverter, I would definitely consider one. It will eliminate a lot of problems for you trying to keep your panel leg-balanced without overloading the inverter when you turn on a big load.
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Chris
Yeah. I did some reading on those last night. Seems like the way to go. I need to do some more reading and thinking. It may be simpler to use one of these and go with a 120v inverter. -
Re: 240 vs 120 volt inverters
Argh. ( Runs screaming from the room )Everything is electric. Water heater, stove, dryer, radiant wall heaters with fans, and a rather large window A/C unit.Powerfab top of pole PV mount | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
|| Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
|| VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A
solar: http://tinyurl.com/LMR-Solar
gen: http://tinyurl.com/LMR-Lister , -
Re: 240 vs 120 volt inverters
I have a 70+ year old home and insulated the walls and ceilings, plus changed all the windows and doors to double pane vinyl (or wood for doors). Installed operating skylights for light and ventilation. Also insulated the attached garage. Used CFL (and later LED) bulbs to reduce heat gain (CFL lights are not pretty). It made our home much cooler in the summer and reduced heating costs in the winter (we are in a temperate climate--So our insulation is much less than in many places in the country would use--But from zero insulation, it was a huge improvement).
For you, looking at your present home for energy efficiency (new high efficiency air to air heat pump for heating/cooling/hot water) would be a great start. Reducing power usage by your appliances (refrigerator, computers, TVs, sat/cable boxes, etc.) both reduce direct power usage and secondary costs to pay for A/C to remove the heat outside.
For cooking and clothes drying... Can you install a couple hundred gallon propane tank for emergency use on your property? Propane may or may not be cheaper than electric for your usage (given the variable prices of propane, delivery, tank rentals these days)--but it would reduce your emergency power usage for an off grid power system.
For cooking, there are some things you can do that will reduce electric usage. If you cannot use propane, Induction cookers are pretty efficient and don't heat up the room (compared to resistive heating or even natural gas/propane).
And if you have Asian markets near by, they frequently sell thermal cookers--You heat/boil the food (stews, etc.) on the stove and then throw the pot into a large thermos cooker for 2-4 hours (sometimes, I will reheat for another 2-4 hours of cooking). Sort of like the old crock pot cooking with a lot less energy usage.
And there are sometimes alternatives such as stove top (or even propane powered) Mr. Coffee and a thermos to keep the coffee warm.
-BillNear San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset -
Re: 240 vs 120 volt invertersLooks like leaving the stove and clothes dryer on the grid for day to day use is my best option. I can get Interstate GC2-HXD batteries ( http://www.interstatebatteries.com/cs_eStore/content/product_info/golf_f.asp ) for around $100 each through my garage account. For the money the 4548 seems like the way to go to be able to use my larger 240 items with generator support, and keep my battery bank at 464ah?
There's two golf courses in our area here and both of them use those Interstate batteries in their carts. I think they're a pretty good battery from what I've seen, on par with Trojan T-105's.
From what I gather you want to do this to have backup power, it's a fun project where you will learn a lot of things, and you can probably use the system on nice solar days to offset some of your grid usage. From that standpoint, the 4548 is perfect with a 4 kW generator. You will be able to run any of the high-draw 240V appliances on your list in an extended power outage by pre-starting the generator and scheduling the big loads so you don't load the inverter to more than about 1,500 watts with your small battery bank, while the generator carries the bulk of the load. It will work perfectly and even be able to run the oven in the range while using the surface elements, along with carrying other normal loads at the same time.
If you have aspirations of going completely off-grid with your system, then I'd say you want more convenience because scheduling loads gets your wife irate with time, and it gets old. We did that for too many years. You'd want the bigger inverter and more batteries, the same 4 kW generator but with auto-start, and more solar power.
While most people look at these high-draw electric appliances as being not practical for off-grid - I have never looked at it that way. When my wife got tired of our lifestyle after watching every watt for 7 1/2 years, and she will NOT allow a gas line into our house, I had to figure out how to do it without breaking the bank. Generator Support is the way to make it happen. It's really, really cheap and efficient compared to an elaborate stacked inverter setup with a huge battery bank. So it is doable and we are very happy with our off-grid electric appliances because on really good days my wife can make baked chicken in the oven TOTALLY on renewable power. While on the bad days with lots of loads on we have to use the generator support. So our off-grid electric appliances are dual fuel - we have the option of running them on RE power, and you don't have that with propane appliances.
So while some will gasp, clutch their chest and tip over when you mention these kinds of high draw things on an off-grid power system - they only do that because they have no experience with using gen support to run 'em.
There only a few inverters that can do generator support at the power levels you're looking at - the Schneider Conext/Xantrex XW-series (as well as the older SW/SW Plus series) - the Outback GS8048 Radian - and apparently SMA makes some off-grid inverters that can do, but I have limited knowledge of those. And that's it - that's the list of what you have to chose from if you want an inverter with real gen support. And unfortunately, the inverters on that list are the more expensive ones there are.
Magnum Energy is supposed to releasing their new MSH4024RE (I think very soon now) that also has generator support. But it's 24V, 120V only, and not stackable. So I don't think that one would be a good option for your needs.
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Chris -
Re: 240 vs 120 volt inverters
In fairness to those of us who do gasp, clutch our chests, and tip over a lot (bad inside joke) at the mention of high power consumption off-grid Chris's system is not exactly cheap or simple.
Most of the time off-gridders want both. With perfection. And gold plating. For less money than they spend on grid power.
That doesn't happen. -
Re: 240 vs 120 volt invertersCariboocoot wrote: »In fairness to those of us who do gasp, clutch our chests, and tip over a lot (bad inside joke) at the mention of high power consumption off-grid Chris's system is not exactly cheap or simple..
No, but for what it can power, for what I got in it, it is. Try running our loads with just inverters and batteries and solar and wind. THEN you're going to spend some SERIOUS money! The point is that the generator is a pretty compact, relatively cheap high output power source compared to RE things that make power. Don't be afraid to use that generator. With same careful engineering you can maximize its efficiency and get by pretty nicely without breaking the bank.
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Chris
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