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Looking for inverter suggestion to set up a critical backup system while cutting utility bill.

wcpastures

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I am planning on setting up a solar backup system for critical loads including at minimum enough power to run a well pump drawing 6A @ 240V plus a large chest freezer and fridge.

I do not expect to have much extra power to sell back to the grid so although I like the idea a grid-tie hybrid (I was considering Sol-Ark) I'm not sure it will be worth the extra $ for my situation.

I currently have grid power. My panel has an interlock breaker for generator input that could be used to manually switch between grid and solar input on sunny days when the load is light and of course when the power is out. I’m still undecided if this inconvenience is worth the cost savings of avoiding the need for a hybrid inverter. Open to suggestions for this application.

I already have the following equipment:

* 4 x 230W, 24V panels

* a 40amp AIMS Power charge controller (model: SCC40MPPT)

I plan to buy FLA batteries locally, most likely US Battery or Trojan

I am leaning towards the low-frequecy type inverter that I hear are reliable, capable of the startup surge of the well pump and less susceptible to EMP?
 
I'm building the same type system you are but I'd like to run my central air heat pump and water heater full time.
I want to stay off-grid because of the headaches of tying onto the grid (and $$).
I was looking at the LVX6048 hybrid inverter which is grid-tie capable. I think it's low frequency. Grid-tie capable units usually are.
This inverter pretty much does it all and supports 6kw. I will use two unless a newer model comes out that's better.
 
1000 watts of solar panels isn't going to be enough to run a chest freezer, family sized fridge, and a well pump.. I don't know what size fridge you have, but mine pulls 3.6kWh/s per day.. My small basement chest freezer pulls 600.

You should get a kilowatt meter ($30) and plug it into each of the appliances for a couple days and figure out how much power you'll actually need... but suffice it to say, unless you are in a very sunny southern location, four 230 watt panels isn't going to cut it.. and more likely, they will leave your lead acid batteries run down causing them to sulfate and have a very short life..

You can under size a lithium battery bank, worst case is the proverbial lights go out when you run out of energy.. but if you don't have enough solar power to keep lead acid batteries charged, they will die quickly.
 
1000 watts of solar panels isn't going to be enough to run a chest freezer, family sized fridge, and a well pump..
I am willing to add more panels if needed. I can fit all 4, 230W panels on the shed where I was planning on setting up the battery bank and inverter. My current charge controller can handle up to 2600W of PV if I use a 48V battery bank with a maximum 192V input voltage. I can use the house roof for more panels if needed but I will get into diminishing returns if I go much beyond that as we have partial shading on the roof. Also I heard you should not mix panel types, if I'm using 24V, 230W panels I need to stick with that? These panels are about 7 years old and I'm afraid are considered "outdated" if I need to add more is it a problem to add different panels to the same array?
You should get a kilowatt meter
I have one, the freezer and fridge draw about 130W each continuous.
I also remeasured the well pump, the MAX amps my Fluke meter is picking up is 6.3A from one leg of the 240V pump. I noticed it increased from 2A to 4A to 6A over a second or so which makes me hopeful it is a soft start pump?
 
I am planning on setting up a solar backup system for critical loads including at minimum enough power to run a well pump drawing 6A @ 240V plus a large chest freezer and fridge.
I have installed something similar and describe it in this thread.

The primary purpose of the system is for grid outage backup.
The secondary purpose is to run the pool pump off-grid, and maybe a few other bits n pieces as the solar PV has capacity to do more work.

But first things first, conduct an energy and power audit so you can correctly scope the system requirements. I go through my numbers as an example.

In my case an opportunity came recently to double my battery capacity for not a big outlay, so I am about to install the second bank and do a few cabling and set up improvements. I update that thread on my progress. I'll probably get into it this weekend.
 
I am willing to add more panels if needed. I can fit all 4, 230W panels on the shed where I was planning on setting up the battery bank and inverter. My current charge controller can handle up to 2600W of PV if I use a 48V battery bank with a maximum 192V input voltage. I can use the house roof for more panels if needed but I will get into diminishing returns if I go much beyond that as we have partial shading on the roof. Also I heard you should not mix panel types, if I'm using 24V, 230W panels I need to stick with that? These panels are about 7 years old and I'm afraid are considered "outdated" if I need to add more is it a problem to add different panels to the same array?

I have one, the freezer and fridge draw about 130W each continuous.
I also remeasured the well pump, the MAX amps my Fluke meter is picking up is 6.3A from one leg of the 240V pump. I noticed it increased from 2A to 4A to 6A over a second or so which makes me hopeful it is a soft start pump?
I would highly recommend going to a 48 volt system.. Stick to SMA, Outback or Victron equipment..

130 watts x 24hrs = 3120 watt-hours of energy.. Just that alone would be more than your 4 panels are going to generate unless its a nice long summer sunny day. <<don't count on it, especially after a storm.

Those 230 watt panels are probably going to make about 170 watts peak, and that's only for a couple hours a day, the rest of the time, they'll make 100 watts or so, and if they're on a fixed slope shed roof, probably even less.

Go buy a bunch of used panels from Santan solar.. apparently, they have a good reputation for selling good used solar panels at about 1/2 the cost of new.

Don't mix panels on the same "string".. but you can have multiple independent solar arrays charging the same battery bank. Maybe one array of 250 watt panels and another array of your 230 watt panels using a different (smaller) charge controller.

The well pump isn't a big issue unless you have 5 people in your family and they're always flushing toilets and taking showers.. other than that, well pumps generally draw little energy because they only run for 20 seconds at a time. The well pump is more of an inverter issue because its going to require a good source of power and most "cheap" inverters won't be able to start it.

Solar is great, panels are cheap.. always go bigger than you need with your array.

Check PV Watts to see how much energy your panels will make in real life for your location. PV Watts is very accurate.
 
Solar is great, panels are cheap.. always go bigger than you need with your array.
Yeah I would like to add a larger array. Your right panels are cheap now but I have partial shading issues if I install on the house so I think I would need to use optimizers, which adds a significant cost in comparison to just panels. With the sun angle this time of year in Ohio the trees are shading the house until nearly 11am. Once the leaves fall a little more sun will get through in the morning. The other factor is we will most likely be moving within a year or two. I definitely still want to at least size the inverter for future expansion.

Stick to SMA, Outback or Victron equipment..
What about Magnum? any idea which of these would be most EMP resistant?
 
Yeah I would like to add a larger array. Your right panels are cheap now but I have partial shading issues if I install on the house so I think I would need to use optimizers, which adds a significant cost in comparison to just panels. With the sun angle this time of year in Ohio the trees are shading the house until nearly 11am. Once the leaves fall a little more sun will get through in the morning. The other factor is we will most likely be moving within a year or two. I definitely still want to at least size the inverter for future expansion.


What about Magnum? any idea which of these would be most EMP resistant?

None of the inverters on the market are really EMP resistant.. Even the Sol-Ark's claim of EMP resistant is a gimmick.

EMP's come in two flavors: 1) Conductive and 2) Radiative

When companies selling consumer products claim some type of EMP protection, they are referring to the conductive component. They are referring to an EMP coming into the house through your grid connection.. IE: Being "conducted" down the wire feeding electricity to your home. They might even claim resistance to the EMP being coupled right through your own home's wiring. These claims are probably legitimate as its not difficult to provide conductive surge protection in any device.
This type of protection is provided by a fast surge protector.. not fundamentally any different than the surge protector in your little power strip on the floor with the glowing red power switch, just a lot better.
Siemens makes a very high quality whole house unit called an FS140 that has a 1 nanosecond response time. I have one on my home myself.

But unless your electronics device is sitting inside a completely sealed Faraday cage, no inverter or EMP protection device can stop the radiative component from directly coupling into the printed circuit boards.

There are two basic kinds of EMP: 1) Solar and 2) Nuclear.
Solar is easy to stop and you don't need special equipment, you just disconnect your home from the grid.. easy.. done. You only need some kind of warning so you have time to do it.. and we watch the sun 24/7 now.

Nuclear EMP is almost impossible to stop without a Faraday cage rated for the type and power of the EMP. Noticed I said "rated for".. that's because technically, being inside a metal building provides some protection. The trick is to have enough attenuation that the EMP doesn't blow out your electronics..
A sealed galvanized trash can, with the cover taped closed with conductive tape, will provide about 40db of attenuation. 40db happens to be a 100 fold change in signal amplitude.
A standard fission bomb detonated at the optimal altitude will induce about 50,000 volts per meter into all conductive surfaces. 50,000 divided by 100 = 500 volts per meter.. or 5 volts per centimeter. Now imagine your electronic device has a wire inside that is 6 inches long and connecting one circuit board to another.. that 6 inches = 15 centimeters x 5 volts = 75 volts under ideal circumstances which favor the EMP. Its not too bad..
But remember, that's a sealed trash can.

Thing is, those numbers apply consideration to standard nuclear weapons.. In order to change a nuclear weapon into a specialized EMP bomb, you simply change the neutron reflector (called a tamper), to something less reflective to gamma.. and presto! You have a Super EMP Weapon capable of a theoretical 200,000 volts per meter.. Not a single item in that trash can is going to survive.. and that Sol-Ark, as well as every other device not in a special Faraday cage, is going to be a paper weight.

It's a win-win for the companies claiming EMP protection because 1) they have your money and 2) Your warranty claim won't mean squat after it happens.

Your only hope for having a working solar system after an EMP attack is to have spare components protected in a Faraday cage, and a good one at that.
I keep a Radian 8048, FlexMax charge controllers, etc, behind 4 layers of steel-aluminum-aluminum-aluminum. Most items are behind two layers, the really critical stuff is behind 3 and 4 layers. Each providing 40db of shielding.

Solar panels only need 1 layer.. if not connected to anything, they are naturally very resistant to EMP's.

Magnum is a good inverter.
 
1000 watts of solar panels isn't going to be enough to run a chest freezer, family sized fridge, and a well pump.. I don't know what size fridge you have, but mine pulls 3.6kWh/s per day.. My small basement chest freezer pulls 600.
I do have access to grid power so if I get the proper inverter/charger I can supplement power from the grid/generator, correct?

Another question I have is if I have the main breaker for incoming grid power shut off so I can run off gen/inverter power (I have an interlock on my panel instead of a transfer switch) then how do I supply power to the inverter/charger to charge batteries and maintain power when load are high and or sun is not shining? Or is this not possible with an off-grid inverter without turning the main breaker back on?
 
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I do have access to grid power so if I get the proper inverter/charger I can supplement power from the grid/generator, correct?
Yes, absolutely.. but with only 1000 watts of panels, you're going to be supplementing a lot.
 
Yes, absolutely.. but with only 1000 watts of panels, you're going to be supplementing a lot

Yeah I know, I hope to add more panels if we move. I checked out Santan solar as you suggested and their used panel prices are unbelievable! the optimizers that I would need would cost as much as the panels though. But I would like to make use of the 1000 Watts for now Unless I will be loosing efficiency thru the inverter/charger or would it just "pass-thru"?

When I know that power draw will be very high (running the water heater...) I could manually flip over to full grid power if needed or are you saying that would not be necessary? I would basically be setting up the inverter/chargers to act as a "hybrid" inverter except that it will not be able to push back to the grid witch I don't think I will use (especially with only 1000W of panels). Again how is this wired up? (see second part of last post)

I was looking at the Magnum 4448PAE since there is local Magnum Amish dealer that can service / stock parts and I figure they must be dependable if they count on them for their 100% off-grid use but they don't hook to the grid so are not fully aware of the "hybrid" capabilities. BTW does anyone know if Magnum is still American made? I am also comparing it to the Outback and Victron as you suggested if it will do what I want.
 
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I keep a Radian 8048, FlexMax charge controllers, etc, behind 4 layers of steel-aluminum-aluminum-aluminum. Most items are behind two layers, the really critical stuff is behind 3 and 4 layers. Each providing 40db of shielding.
Do you currently use Radian also?

I like that: "The Radian GS8048A and GS4048A feature dual AC inputs
for grid/generator flexibility with no external switching required"

I think this is what I have been looking for and found one on Ebay for a good price:
 
Do you currently use Radian also?

I like that: "The Radian GS8048A and GS4048A feature dual AC inputs
for grid/generator flexibility with no external switching required"

I think this is what I have been looking for and found one on Ebay for a good price:
Nope.. our Radian and Flexmax charge controllers are stored in a Faraday cage in case the world ends..

We only use the Sunny Island x2 inverters for normal grid outages.
 
Nope.. our Radian and Flexmax charge controllers are stored in a Faraday cage in case the world ends..

We only use the Sunny Island x2 inverters for normal grid outages.
ok, but you apparently think the Radian is reliable inverter / charger? it seems it will do what I want, I do think your right and I will want to add more panels ASAP to get to at least 2kW (my 40 Amp AIMS controller maxes out at 2600W.) Thanks for letting me know about Santan solar, they have some cheap 230W panels that I think will be compatible with my existing 230W panels. Hopefully I can figure a way to string them together without getting into shade loss issues
 
ok, but you apparently think the Radian is reliable inverter / charger? it seems it will do what I want, I do think your right and I will want to add more panels ASAP to get to at least 2kW (my 40 Amp AIMS controller maxes out at 2600W.) Thanks for letting me know about Santan solar, they have some cheap 230W panels that I think will be compatible with my existing 230W panels. Hopefully I can figure a way to string them together without getting into shade loss issues
If shading is a problem, just add more panels.. panels are cheap and last a long time.

Yes, Radian is one of the better models available.. arguably #2 after the Sunny Islands..
 
If shading is a problem, just add more panels.. panels are cheap and last a long time.

Yes, Radian is one of the better models available.. arguably #2 after the Sunny Islands..
I've heard that you will actually decrease the array output if you add panels in a shaded area?
After looking into it more, it seems wiring in parallel as much as possible should help minimize loss:

I think I will order the Radian
Also I plan to pick up another charge controller (probably an Outback) that will help separate some of the shading loss.
The Radian can work with more than one charge controller even if it's not a Outback branded (FlexMax) one right?

edit: Well it looks like their "Load Center" and System Display and Controller are pretty much a requirement?
 
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I've heard that you will actually decrease the array output if you add panels in a shaded area?
After looking into it more, it seems wiring in parallel as much as possible should help minimize loss:

Also I plan to pick up another charge controller (probably an Outback) that will help separate some of the shading loss.
The Radian can work with more than one charge controller even if it's not a Outback branded (FlexMax) one right?

I think I will order the Radian
edit: Well it looks like their "Load Center" and System Display and Controller are pretty much a requirement?

It is true that one shaded panel can sink an entire string of them. What I meant was to add more panel strings in places where there isn't shade.

The radian is just an inverter, it has nothing to do with the DC Coupled charge controllers other than that its drawing power from the same DC Bus, so yes, it will "work" with any charge controller.. It should be noted that the Radian requires the Outback MATE controller to be programmed correctly.. that MATE interface, (Mine is a MATE3) can also "work" with the FlexMax Charge Controllers.. But if you had another charge controller hooked up as well, then it would still work to help charge the batteries, but it would not communicate with the MATE interface. This isn't a big deal.

The "Load Center" is absolutely NOT required.... While it has its convenient benefits for installation, its just box full of circuit breakers and bus bars.. I didn't bother getting one. Too overpriced in my opinion for something that doesn't actually do anything.. if the price was $400, I might have got it, but at $1000+, hell no.

You can go to Midnite and buy all the DC circuit breakers you want for $10 to $15 each and snap them on some DIN Rail.

It all depends on your budget vs how handy you are with building things.

This is also while I like AC Coupling.. its far simpler as you don't need charge controllers, DC circuit breakers everywhere, etc.
 
It is true that one shaded panel can sink an entire string of them. What I meant was to add more panel strings in places where there isn't shade.

The radian is just an inverter, it has nothing to do with the DC Coupled charge controllers other than that its drawing power from the same DC Bus, so yes, it will "work" with any charge controller.. It should be noted that the Radian requires the Outback MATE controller to be programmed correctly.. that MATE interface, (Mine is a MATE3) can also "work" with the FlexMax Charge Controllers.. But if you had another charge controller hooked up as well, then it would still work to help charge the batteries, but it would not communicate with the MATE interface. This isn't a big deal.

The "Load Center" is absolutely NOT required.... While it has its convenient benefits for installation, its just box full of circuit breakers and bus bars.. I didn't bother getting one. Too overpriced in my opinion for something that doesn't actually do anything.. if the price was $400, I might have got it, but at $1000+, hell no.

You can go to Midnite and buy all the DC circuit breakers you want for $10 to $15 each and snap them on some DIN Rail.

It all depends on your budget vs how handy you are with building things.

This is also while I like AC Coupling.. its far simpler as you don't need charge controllers, DC circuit breakers everywhere, etc.
Ok good, yeah I think I will put together my own panel, save some $, and I can customize it the way I want. It almost seems the "Load Center" makes it more complicated.
Outback publishes their install manual for the Radian which is helpful at seeing how this will go together:

I am really starting to get excited about Outback, beats Sol-Ark hands down on price and they are not made in China like Sol-Ark now is.
The only thing I can see Sol-Ark 5k having that the Outback Radian does not is the charge controller integrated, but I would still prefer to have those components separated for serviceability.
 
Ok good, yeah I think I will put together my own panel, save some $, and I can customize it the way I want. It almost seems the "Load Center" makes it more complicated.
Outback publishes their install manual for the Radian which is helpful at seeing how this will go together:

I am really starting to get excited about Outback, beats Sol-Ark hands down on price and they are not made in China like Sol-Ark now is.
The only thing I can see Sol-Ark 5k having that the Outback Radian does not is the charge controller integrated, but I would still prefer to have those components separated for serviceability.
I don't think the load center complicates things, it does make connections easier.. but the expense just isn't worth it.. $1000+ for a steel enclosure with $300 worth of stuff in it.. that kind of thing is for people who just want to attach wires and be done.

You need breakers on the AC out.. that can be a regular Home Depot breaker panel.. You'll also need DC breakers for your charge controller and battery leads and Midnite makes a bunch of different sized ones for that.

Other than what's mentioned, just some copper bar stock and the ability to drill and tap some screw holes into it.. Maybe get a steel box to make it all look nice.
 
I don't think the load center complicates things, it does make connections easier.. but the expense just isn't worth it.. $1000+ for a steel enclosure with $300 worth of stuff in it.. that kind of thing is for people who just want to attach wires and be done.

You need breakers on the AC out.. that can be a regular Home Depot breaker panel.. You'll also need DC breakers for your charge controller and battery leads and Midnite makes a bunch of different sized ones for that.

Other than what's mentioned, just some copper bar stock and the ability to drill and tap some screw holes into it.. Maybe get a steel box to make it all look nice.
yeah and to be fair the box is $595, the $1000.00 is everything pre-wired, but still! Sometimes companies add some time onto the warranty if you buy the extra ad-on but I didn't see anything about that. I like that Outback seems to be willing to sell you just the components that you need. Instead of spending that money on the box I can buy the FlexMax charge controller and extra panels...
I'm waiting to see if I can get this from a local dealer at a comparable price as online, if not who is a good supplier?
 
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