Parallel 3 Inverters Together, off grid 48V 120/240, 1-Month Update
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- Опубліковано 7 вер 2024
- Last month I paralleled 3 inverters together to increase their output. Now it has been one month of running my home and garage on them and it's time for an update. Bottom line, they have been working excellent.
The inverter is from Growatt. It's the SPF 5000ES model. It can output a continuous 5000 watts (5kW) of AC power at 230 or 240 volts (50 or 60 hertz). I'm using an auto-transformer from Solar Edge to provide a neutral so that I can have 120/240V split-phase. Total output: 15kW Each inverter has a built-in solar MPPT charge controller.
Related videos:
1. Introduction to this inverter: • Best Value Inverter, A...
2. Load test of one inverter: • Full Load Test and Mak...
3. Parallel 3 inverters wiring: • Paralleling 3 inverter...
Update: There is no longer a discount code available.
Affiliate Links:
Growatt 5000W Inverter with 450V MPPT Charge Controller 5000ES: signaturesolar...
Auto-Transformer, 5000ES: signaturesolar...
EG4 Battery, 48V, 100Ah, 5.12kWh, LiFePO4, Server Rack design: signaturesolar...
Waterproof EG4 battery: 48V LiFePO4 Lithium Battery with Bluetooth, EG4 Brand: signaturesolar...
Disclaimer:
My videos are in no way intended to be instructional "how-to" lessons. I am simply documenting my project for informational purposes. Property damage, personal injury, or death may result, even when following manufacturer's instructions. I cannot be held liable for such damage or injury. It is YOUR OBLIGATION to ensure that you are complying with any local and federal laws as well as code and permit requirements.
David Poz, LLC
I lost a nuetral once. Right after the superbowl. My TV lit on fire out of nowhere. I threw it outside into the snow! I let the house air out. Then my bedroom TV lit on fire! I had to throw it out in the snow too! My neighbors were probably thinking I was pissed about the superbowl lol
How you loose ground ?, pls explain
David, you would be a great politician as you carefully thread your way through the discussions without generating any ill will any of the suppliers. Very informative. Thank you.
That was really good and valuable feedback David. Thanks. Yes, I would like to see the install at your friends tiny house.
Benny your everywhere. Best go work on some editing. Thank Dave.
He said
Good update, thanks for sharing
Thanks Dave brought one of those growatt 5000es about 3 months ago after watching you set up yours it works great we put in a 3 way switch from grid to off grid we did it that way in case the inverter crashed but it’s still working fine we are off grid 90 percent of the time , still very happy with it thanks for all your videos Dave an Kazzy south aussies
Hey David, great update, I contacted you about using this system in Kenya. We too will be using at least 2 inverters in parallel . We are very excited to get the system up, should be off grid and running with in the month. Will try to keep you updated when that happens.
Use the term in inexpensive instead of cheap,
Great job Dave
or best value for money
Apart from the very informative content, the best part for me is the cute toddler's Tarzan call like imitation during the title roll. I always rewind it a couple of times...❤👌😍👍👍
That is also my favorite part of watching @DavidPoz Videos. So cute
By all means, please show the install at your Florida friend’s tiny house. Your update was great keep the videos coming!
Great video of you explaining the GroWatt inverter efficiency , compared to the Sun inverters while running on the PV modules at daytime vs the batteries at night . What a great way in helping a friend in need in Florida to go solar by donating an extra inverter is very appreciative . Props to ya and May The Solar Be With You .
Great update, thanks Dave. I am running two of those inverters with the auto transformer, this is how I wired it up, Ran power from my inverters to a dedicated 240v breaker box (no 120v) , then from there on a 25 amp breaker (this will be the auto trans/120v disconnect) to a separate breaker box for 120v only, power this box through another 25 amp 2 pole breaker ie input power through the terminals, then take power from these same terminals to the auto trans, so if that breaker trips power will still be maintained at the auto trans, but power to 120v circuit will be cut. Then run the neutral from auto trans into the 120v box and anything downstream feeding from this box, but not back to the dedicated 240v box. This is going to be difficult to set up in a house that has 120 and 240 v loads coming out of the same breaker box!!! you will have to separate those loads.
Thanks for sharing your solution. Sounds good.
Being able to run an inverter with just solar, no batteries, is simply amazing. The idol consumption is a bit high. However the money you save on this unit allows you to buy more panels to offset that. It seems to have done the best under the poz extreme test as well.
What? No battery at all? Where does it say that? Interested in doing this since the battery resources are hard to come by.
@@erichibar4746 When solar is producing, the inverter uses it to run, but once the solar is no longer producing, the inverter uses the battery bank. So, yes you could use inverter without batteries but only while solar is producing power.
In reference to the split phase setup, you could use a 2 pole MCB to supply the load centre and thus avoid any imbalance issues in the event of one leg tripping . If a 2 pole MCB (common in marine applications as there is no neutral) is difficult to source a 3 pole MCB can be used in this case and leave the spare pole idle without any problems.
Please define a MCB so I can source one. Thanks
@@communityspringwater9353 Miniature circuit breaker. They are the de-facto style circuit breaker in many countries outside of North America. Basically we need a two pole breaker where one side is 42A (~5kw@120v) and the other side is >=63A (~15kw@240v). Run the neutral through the 42A side and one side of the inverters through the other side. If the neutral trips, then it will also trip the 240v from the inverters.
I think we have to ask some manufacturers if it is okay to gang two separate single pole breakers together.
@@captainobvious9188 The problem is I've never seen a breaker with different ratings on each pole. It's _not_ okay to handle tie two separate breakers together in this case because of the trip-free mechanism. This is the feature where it can trip even when the handle is held down. Since a breaker can be off when the handle is on, this could lead to one breaker staying on when the other trips.
What we need is a set of breakers with an 'internal' linkage which ensures common trip. I imagine some industrial breakers support this but the problem is finding them.
@@captainobvious9188 Wrong, to protect the autotransformer you use a 40 amp double pole breaker, (or 50 amp since NEC allows going up one standard size when amperage falls between standard sizes.) The breaker will allow up to its rated on ONE Pole, or up to rated on Both poles of 240 v load.
About to install two of them myself so will be watching your channel for an update.
If you have room.. put a wall up in front of your setup. making a small room. and then line it with rockwool insulation. Rockwool will kill that noise all day long :)
HOWdy D-P,
thanks
COOP
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Great video David. I've learned to check mppt amp rating on panels match that of the inverter and also the solar edge auto transformer set needs looking at. I await in depth teak video of that change you'll make to the transformer. Many thanks again. Keep up the good work. 👊🏾🇬🇧🇯🇲
Always appreciate your updates and honesty on components.
For your friend in Florida, it would be interesting to him try out a HotSpot DC/AC mini split
When you lose the neutral the ckt tries to complete thru the bonding screw in the service panel. The bare ground to the gnd rod
will pass a small amount of current which is the problem. That very low voltage condition will damage electronics. I witnessed this at my home when the neutral of the service cable separated at a compression splice. The power company paid for the damaged stuff.
Thank You for all of your videos that you did. I am enjoying all of them
I bought the Growatt 5000 and will be connecting it soon. Your videos are helping me sooo much.
How about an update?
Excellent update your friend in fl without air conditioning is definitely brutal yes we basically have pretty much one season hot, hotter or hottier 70 degrees is a jacket day 😁
That's what I've heard. I visit him in Maine during the summer, never been down to his place in Fl.
thanks David , you are awesome
NICE brother. One thing I love about the Mpp solar inverters is the built in Mppt CC. Love how they fill up the batts then just us the PV to run the loads. This is why I do not mind running a dump load. I know the dump load is not micro cycling the batts. The next videos going to be so cool. Thanks for sharing. God Bless.
Thanks for watching and commenting Bobby. I love your videos too. You have done more with dump loads than me, but hopefully I'll get to do more of that in the future.
Thanks for the comment. The benefit of having the 3rd controller is for an N+1 configuration. When one inverter dies, you can continue to run load without disruption.
This inverter is my first choice! I'm building a island solar system in my house to save money with producing PV power and to be able to add generator power if we have a blackout. I've heard only good news about this growatt!
Nice video.
Greetings from Germany. ✌
Excellent video! What I am having a hard time with is determining how much power I need for a house that isn't even built yet! From my research, I believe one 5K watt inverter should do me fine but if two will power things like an electric stove, water heater and a dryer, than maybe that is the way I will go in order to save money on propane. I would use natural gas for the stove, water heater and dryer but there is none at the property, at this time.
David, thank you so much for all the information.
I live in New Orleans and just went through the power outage related to Hurricane Ida. I didn't have a backup power system so evacuated after the storm. The experience led me to believe that I need to acquire a backup power system. The most common solution seems to be portable generators. I live in a rented house that really has no capacity to store a generator and definitely no capacity to store gasoline. As such, I am considering using my car as the generator and attaching a high capacity inverter to it. Given the much larger gas tank, the engine efficiency, lower noise, and the emission controls already present in a car relative to a portable generator, it seems like perhaps an even better solution in many respects. Given the things I'd like to run in such an emergency situation (fridge/freezer, two window A/Cs, and a desktop computer) and have some overage for maybe a TV and phone charging, I think a 3500 watt inverter would be sufficient. I am also considering buying a wireless meat thermometer attached to the car engine which I can set to trigger an alarm if the engine temp gets too high.
Does this sound feasible to you? Most of the inverter videos that are on youtube, including yours, are focused on off grid use of inverters and large battery arrays. I am not sure whether my single car battery with the engine running can properly charge a 3500 watt inverter.
This solution seems feasible but the fact that absolutely no one, that I am aware of, is employing this solution makes me think there is something wrong with my theory. I have absolutely no electrical or automotive background adding to my nervousness.
Any feedback you could give me would be greatly appreciated.
Hi, I'm sorry to hear you had to evacuate, but glad you lived past it.
There are several reasons this is not done, but the short answer is, no.
A brief understanding of why:
Your plan for a 3500 watt inverter, at 12 volts, will pull 292 amps. Your battery will be able to supply that for a few seconds, but to power something longer than a minute you are relying on your alternator. The average car alternator outputs about 60 amps. This means you will deplete your battery, with the alternator running, in only a few minutes. At that point your battery will be dead, not start your car. You also run the risk of over-heating and burning out your alternator because it needs cooling. The built-in fan on the alternator is looking for higher RPM's to move enough air (CFM) through the alternator to keep it cool. Since your situation would have the car idling at low RPM's it won't cool itself adequately.
I might suggest looking into building a battery based power system, or buying one like this: ua-cam.com/video/briFUcQVlwA/v-deo.html They can be re-charged from the car, but only at 10 amps so it won't have the same problems.
@@DavidPozEnergy Another youtuber suggested that paralleling 3 deep cells between the inverter and the car battery would do the trick. Does that sound right to you?
Thanks for lessons from your personal experiences. I am starting to warm up to GroWatts needing an auto-transformer for usa 240vac split phase, plus the 120vac legs. Will look for your next video on these subjects for any improvement ideas. Thanks ;+) Bill in No. CAL
I have the 3.5kw model 2kw of second hand panels -- 100ah 4 _ 12 v =48v batteries ---- soon will have autostart generator hooked up- am very pleased with it -- down side is trying to make sense of all the menu's and settings
So you are getting by with just 10k. Also you stated no gas appliances. That's encouraging. I might jjust be able to get by with 5k in my camper.
Yes, that's right. No gas, oil, propane, or wood. If I wanted to turn on every heater, and stove top, and oven, etc. I could draw more than 10kW, but we don't under normal day to day life.
Thank you! For stating we use "split phase". So many ppl think the US uses only Single Phase, hence why we have 120V. 👍😎
I've even heard US ppl say we only use Single Phase. *sigh*
It all comes down to intricacies in terminology. Split-phase domestic power is a subset of single-phase power, so those people are still correct. The real debate comes when somebody says two-phase power, but I'm not going to go sown that rabbit hole today.
Very nice units, indeed.
Thx for the update.
hey David, love your videos. just one thing i would love to see. wiring diagrams to show how you hooked everything up. i learned a lot from you, thx
Thanks for the feedback. I've been asked for a wiring diagram a few times in the past couple months, so I think I'll have to make a follow up.
David, As a licensed master electrician, I'd be honored to help you with the safest wiring for your auto transformer.
Thank you. Are you on Facebook to chat? I'm on at davidpozenergy
I'm installing this exact system this week and would love some input on how to wire up the auto transformer a different way!
@@hoosiersolutions4332 Did you find a safe way to install the auto transformer? I will be installing one of these soon.
@Tracy Mathews, I would like that information as well. I will be installing one of these soon. Thank you
Man that is sweet! Getting ready to get more solar panels the generator yeah is noisy you're right about that. I'm trying to go with a 2000 or 5000 kilowatt system with the cheapest solar panels available it'll take forever but we'll see what happens?wish for the money for higher watt solar panels in the 300 watt solar panels so I got quite a bit to catch up on. I was waiting for you to say that you had the whole house off grid that is the sweetest thing I've ever seen!nice job!
Another great video. I would have kept the 3rd one for a spare when one of the others die. And yes, at some point one will die. I had my single 10kw die after only 3 years and it took almost a week to get a replacement and get it installed. Just for comparison, I have a 15kw array of panels and 3 powerwalls. Cost a fortune to have someone setup and install it all, but it is also under warranty.
I have 3 of the inverters. Most of the time you don’t need the 3 inverters. But I started with 2 inverters but when I installed the air conditioning? My power draw was to high. I am on a well. I also have all electric house. Washer dryer range water heater and now 5 mini splits. I can run them all with the 3 inverters.
Great stuff. There´s a problem though coming from a country with few sun-hrs in the winter. If you go offgrid for a typical house you will need to gather all needed energy in two hrs or so, then 15kw will not suffice. Depending on winter consumption, you´ll probably need to triple the amount of watts gathered /hour, to make it thru the whole 24hrs.
Panels are cheap but high capacity inverter/chargers are almost non existent.
David, thanks again for a fantastic update. I'm curious to see what you will be doing with the transformer. I've been running on a smaller "Outback" system for the last 18 months or so - (6KW) - will be doubling my panels to give me 12kw like yours and have similar power requirements for the home/office. I'm currently on 7.5kw worth of Lithium Iron Phosphate battery, and will be increasing that as well with the batteries from Signature Solar when they become available. When done, I'll be selling my whole outback system. I'm also down here in South Florida (West Palm Beach area), and am excited to see what you do with your friend. Cheers, and thanks for the great videos; They have helped me tremendously.
Somehow it seems better and cheaper to run two inverters, 220 by itself and 110 by itself.
Thanks for the update.
Great work David. Surprised that you don't need a Licensed professional to install as we do in Australia. André
Great follow up. Really interested in creating a system with two of these, panels, and batteries to just charge our evs as a full off grid solution.
Growatt advertise 9W of no-load draw, so a bit worrying if you are seeing 80-90W for each unit. Fantastic videos by the way, rare and very refreshign to have such solid, logical, but detailed content on this subject.
The 9W you are referencing might be in standby mode? I'm not sure because I don't know exactly where you are seeing it. BTW, once the inverters have warmed up, I see an average 70W each, plus 14W for the auto-transformer.
@@DavidPozEnergy Thanks for the reply! It was advertised on their website, but despite the fact that I can still picture a rather silly graphic, I'm wondering if I imagined its as I cant find any sign of it. It was something about older units might use 30W but theirs just 9W. I suspect you are right and (assuming im not going mad and they really said that somewhere) its just the standby voltage rather than their draw on the system while inverting.
Can I ask a techy question? Just ignore me if you think this is more of one for their pre-sales. I just wasn't sure of one thing... I understand you wire this up with the AC grid connection as an input to their kit, that AC can then either charge the batteries or feed the house via the inverters output (I understand that in a 'grid tie' the inverter's output is actually hooked up to the distribution panel, in parallel to the grid, and the only AC input to such an invertor is so that the system can sense the voltage, phase and frequency). My actual question: I saw some big relays in one of your vids and I've seen specs metioning time delays of 15ms, does the AC input either get passed on completely in the event of too much demand (over 5kw say), or if the battery/solar is too weak, and the relays flip things round when the battery/solar is good enough? What I mean is, I assume the grid can't be passed through AND use some of the battery (once inverted) at the same time? Sorry, thats a very poorly described question! I'm actually a physics graduate with a good few years of electronic engineering, but I'm a massive noob to the capabilities of this sort of kit, and your vids are making me really jealous so I'm trying to plan an install of my own... Thanks again and I wont be offended if you haven't the time to read my crazy question. P.s. I'm already ordering BMS's from the guys you buy things from, they have a great sales team.
First, establish that we are discussing the category called "inverter/chargers". These are inverters that can also act as chargers. Ok, moving on. In almost every model of inverter, there is a "AC input" and an "AC output" terminal block. Under normal inverting mode these two terminal blocks are separated. At some point the inverter decides to switch from inverterting mode to "pass-through" mode. This is typically done at a battery low Voltage threshold, but sometimes programmed for other trigger points. When this happens the inverter closes an internal relay which bonds the input and output terminal blocks together. This allows the grid (or sometimes generator) to pass through the relay and out to the loads. The inverter is still permanently bonded to this "AC bus" and changes to charger mode. Now the inverter components are drawing from the grid to charge the battery at the same time the grid passes through to power the loads. This is the basic setup, and can get more complicated in some situations.
@@DavidPozEnergy Thats amazing - thank you!!! Makes a lot of sense. I'm off to go research if the Growatt ones can be configured with schedules that tell them to top up the batteries from the grid at a certain time, i.e. over night when my electriity supplier pays me to dump load (pennys /kwh, but better than charging me!). As I plan to get the inverter and battery in place this winter and tackle the solar next year. I have a feeling I might need to keep researching as I'd like if possible to have the option of using wind too, but maybe thats stretching the 'single unit does everything' aspiration too far. There is a youtuber who does DIY similarly and he has solar charge controllers, a wind charge controller and a hydro system all charging the same bank, so I'm quizzing him on that setup too. Anyway, thanks again, I'm really a lot clearer on that aspect of it now.
Your welcome. When it comes time to purchase equipment, please consider using my affiliate linksbin the description of my videos. If you purchase an item through the link, it will help me out.
Multiple sources can charge a single battery bank, but each source (solar, wind, hydro) will need its own charge controller. Most charge controllers on the market only work with solar. If you are using wind then you need a specific wind controller.
Very instrutive. Would like to see the update to just 2 inverters and the stats about it on another month. I guess would increase efficiency a bit. Loose the transformer and have each one invertor doing a phase to have split phase all together. Simpler and even cheaper 👍
Can you please explain that in more detail. As I understand it, each inverter has an output of 240V so how does it get reduced to 120V in the way you're suggesting? I ask because I'm in Europe and want to buy 2 of these here to take to South America and there they have 120V so I need to do the same. I don't understand what you're suggsting. Thanks in advance if you can clarify!
P Cruz These particular inverters cannot be connected that way. You would end up with 240 volts on each leg referenced to neutral, and 480 volts phase to phase. You MUST either use an auto transformer OR use inverters with 120v outputs.
Great video. Thanks
Nice info
Before you take the 3rd one down
I would love to see the 3phase set up with an 3 pause panel box
O, sorry. I already removed it.
@@DavidPozEnergy ok
I am new here!
Awesome DIY channel!
Always looking forward to your next videos... Keep up the spectacular job!!!
Florida! Ugh! at least he comes down here during the "winter" (what ever that means, what's winter? 😜) Any time during the year it would be nice to have some kind of cooling in the house. Even if the only thing the unit is being used for is pulling the humidity out of the air. Lowering the humidity not only makes quality of life a lot better (breathing, sleeping, just being more comfortable) but it also will keep everything inside the house in much better condition over time. Doesn't take much for mold to start growing in random places in the house in Fl when the humidity is >70% and temps are over 80F.
I agree. He says his tiny house is "musty" when he returns in October.
@@DavidPozEnergy If he decides to do a small bit of home automation (wouldn't take much, just using raspberry pi and homeassistant) could have the a/c come on for about an hour each day. That would keep the air clean and combat any mold
Addition: Actually could just use a non-digital A/C unit (turn knobs to set speed/temps) and then use a non-digital power switch. They usually have a dial with pushpins to set activation time(s)
We have the growatt 90kw 3 fase 400v ones at work the work great but get warm and make some noice but they never failed
Different world. Here in Europe, Finland we get 3 phase 240 V AC, I have 3x25A connection.
300 + 210W makes 12kWh per day just for idling power. That is a one big expensive LiFePo drained every day. You could feed all computers, chargers, screens etc. Directly with 100Vdc. That is because they already have universal SMPS which operate 80-240Vac or DC. And then add smaller inverters only for machines which really need AC. DC system would be way simpler and more efficient.
Great video, can’t wait to see update on how to install the transformer, makes me scared if the breaker flips off etc
I posted a comment about that, and here's my solution for a failsafe setup:
Set up a separate load center for ONLY the 120v loads, all of them. Attach the autotransformer directly to the main lugs (or use a 100a double pole breaker, bear with me and I will explain why.) You then feed the 240v input from a separate 240v ONLY loadcenter via a 40 or 50 amp double pole breaker placed IN the 240v load center. This way, a failure or overload of the autotransformer will trip the breaker in the 240v feed ONLY, thus protecting your 120v loads. The 100a breaker can be used as a safety disconnect for the autotransformer, and should never trip except for a catastrophic failure (short circuit) in the autotransformer. (However, the 40 or 50 amp breaker FEEDING this 120v setup will always trip first anyways. ) If you do add the 100a breaker for the autotransformer, install a handle lockout on it to keep it locked ON (breakers WILL still trip with handle locks on, they are required to by UL and NEC code.) That way you won't accidentally turn the auto trans off.
@@mxslick50 I did some research and I don’t think the fluctuating voltage from a floating neutral/failed transformer will trip the breaker, which is rated for current/Amps. I’m also looking for a solution. Perhaps a digital voltmeter like David has to alert for irregularities is the simplest option. Also, a shunt trip circuit breaker can be used with a temp sensor to shut down the circuit, but I haven’t figured that out completely yet. In fact, Solaredge designed the transformer with a temp sensor to shut down their inverters if it gets to hot. I’m surprised Signature Solar hasn’t provided a solution to this serious safety hazard. Seems they could have some liability.
David, eventually I will be using three of these, simply because there are times where I will need the peak current capacity to run a large air compressor. Most of the time, though, I will probably run on just one or two depending on season.
That's cool. Having more gives you the option to add more solar panels in the future too.
@@DavidPozEnergy That it does.
Good video David. I am very happy I went with a Sol-Ark 12K in-lieu of a cheap charger. My fear of using something like this would be for someone who is strapped from money and isn't worried about taking a chance on a cheaply made Chinese product that needs consistent monitoring and could cause serious problems and damage to electrical components in my house. The efficiency percentage of these types of hybrid inverters is very low when you compare them to Sol-Ark at 97% efficiency rate.
I believe Solark is made in China as well. It is however designed in the USA. A quality product for sure.
I've learned interesting points in your in-depth review. Thanks.
Thanks for the video!
With the amperage on the solar panels by the time your energy get to the Inverters you would expect to see some losses, so your 18.8 would fallen to 18.3 or 4 , and I am sure they would of under rated the system just for that eventuality.
Excellent video...
At the 10 minute mark where you talk about beeing overloading the inverter by having more solar amps than the inverter is rated for.
You can connect it to a 1000A solar panel and it will still only draw the wanted 18Amps.
The only thing that matters not to go higher is voltage.
The unit is what draws power and it wont draw more than its rating.
Just like your microwave might be rated for 10 Amps but the house supply and fuse is probably over 60 or 100 amps it's not magically pulling 100 amps just since the supply can deliver it.
It is benifitial to have more solar amps than the inverter is rated for so it can deliver full power in less sunlight or in another way more hours a day at full power
thanks for the hint, In the case of the Growatt inverter, when I plug in two strings of monocrystal panels it sums up to over 18A (~19A), with ca 430 V max voltage, Does it means the inverter is good for 18A * 450V = 8 kW solar power? Could not find an official number but I was under the impression it handles up to 6KW solar input and spits out up to 5kW to AC. I'm currently planning to expand my current one inverter system to a two inverter system and would like to get the panels right. At the moment I'm using 8 * 485 W monocrystal panels, simply because I do not have more space, but have plenty of space for panels for the second system. Any advise on how to get the most solar power out with the Growatt, without stressing it too much?
well sad
@@CarstenDohrmann as long as the solar panel open circuit voltage doesn't exceed the rating of the inverter you are good to go👍
The amp rating on the inverter input is the maximum it will draw, your supply to it(solar) can always have a higher Amp capability.
Super power good update
I would love to see what you have done from the combiner box to the oven. Like the other side of this setup
Loving this series of videos. You are inspiring me!
I will soon be setting up my off grid system using two of the Growatt inverters. (this is 3-6 months out from date of this post, and I will upload videos on my channel of the install and setup.) Here's the solution I came up with for the autotransformer issue:
Set up a separate load center for ONLY the 120v loads, all of them. Attach the autotransformer directly to the main lugs (or use a 100a double pole breaker, bear with me and I will explain why.) You then feed the 240v input from a separate 240v ONLY loadcenter via a 40 or 50 amp double pole breaker placed IN the 240v load center. This way, a failure or overload of the autotransformer will trip the breaker in the 240v feed ONLY, thus protecting your 120v loads. The 100a breaker can be used as a safety disconnect for the autotransformer, and should never trip except for a catastrophic failure (short circuit) in the autotransformer. (However, the 40 or 50 amp breaker FEEDING this 120v setup will always trip first anyways. ) If you do add the 100a breaker for the autotransformer, install a handle lockout on it to keep it locked ON (breakers WILL still trip with handle locks on, they are required to by UL and NEC code.) That way you won't accidentally turn the auto trans off.
A second, but far more costly setup would be to use "Shunt Trip" breakers on ALL of the 120v circuits AND the breaker feeding the autotransformer. A suitable controller must be set up to fire the shunt trips on the 120v circuits when the autotrans breaker trips. This is complex and costly, and there is still a possibility of a brief overvoltage happening on the 120v loads until the breakers all trip.
In either case, an in panel surge protector would be a wise investment for the 120v load center.
This company called seplos seem to have a very good BMS with canbus communication to sma, victron etc.
let me know how you connected and configured the Seplos to the Growatt, please. I'm planning to run two Growatt inverters in parallel with five 15 kWh battery packs (16 raw 300Ah cells) managed by a Seplos each and then connect the Master Seglos to the two Growatt inverters. That should get my house half the year entirely off-grid and in the summer months, I need to top up here and there from the grid. By the way, we living in Northern Thailand, where we have no real frost, but hot (tropical) summer months, and I run the AC 10 months a year.
Great video have your friend look into solar hybrid mini split air conditioner a little pricey but worth it and at night use a battery bank I think it needs 225 ah good luck
lol loving your moment of truth
Awesome Update David!!🤘
Thanks Joe
Thumbs up and subscribed!
Hey David, What are you doing for air conditioning? Are you running your main heat pumps on solar or using mini-splits or window units? Also, I "micro" cycle my batteries all day long like you talked about. This is mainly due to cloud cover. My system can switch from 80Amps in (@56VDC) to 100 Amps out when I get cloud cover and it does this a lot. I assume your still hitting the batteries when you get clouds rolling over? Thanks!
For sure, if clouds roll in and you are drawing close to the solar output the inverters could switch back to the batteries. it will still do that on occasion. But I have noticed that it's less than when I run a more traditional charge controller. But even with a traditional charge controller, it can be minimized with a lower float voltage setting. There are always more than one way to do things. That makes it fun.
I will say that I don't usually have to draw from the batteries during the day. I have about 12kW of solar panels, so even if clouds roll in, I'm still producing at least 6kW. I unusually don't need more than 6kW for the house unless we are using the electric oven.
Air conditioning: I'm running a Mr. Cool mini-split in my house, and an Innovair mini-split in the garage. The Mr. Cool runs flat-out 24/7 (1.3kW) during the hot spells. The Innovair runs at an average of 200W during the same hot spells. That's pretty cool. I might have to change out the Mr. Cool.
Can I make a suggestion for a video? I'd like to see "Off grid power primer for 2021". Might even be parts 1, 2, 3. I'd really like to see a general overview of the components of an off-grid system including panels, batteries, panels, charger/inverter, nuetral, etc., etc., how it all goes together, and then a list of "if I were starting from scratch today for 5KW, 10KW, 15KW system, I'd use these components if I were buying today. Then every few months or a year, if those recommendations change do an update that says, "This (battery bank, inverter) is now a better choice". There is so much information in your videos that I really appreciate, but we have to look at bits and pieces and put them together, and don't know how much is because you were trying out new things or adapting to what you already had. As a playlist with the primer and updates, it would be super helpful!
Good suggestion. Thanks. I once made an overview video, but I don't think it's exactly what you are asking for, is it? ua-cam.com/video/722GNWlEN1g/v-deo.html
Thanks for the update...provide us more info on the 5000 when it's connected down in Florida.
That won't be until winter. But I met up with my friend recently in Maine, where he spends his summers. I'll share that coming up.
@@DavidPozEnergy Hope he has a good sunny spot! I'm struggling with shade patterns and cloudy summer afternoons/thunderstorms keeping my solar yields low. Gonna need more panels.....
Wouldn't it be nice if everything in your house ran on 48 volts 👍👍oh wait pinch me I'm dreaming 😂🤪
Nice channel,. Very good Subscribed
Well done 👍💪..
Thanks david very good information you answered lots of questions that's been in the back of my mind for years I'm in Australia and will translate to aussy can l get to e-mail you about some unanswered questions ....Vince from Australia
2:07.. That's typical in Canada as well.
heya thanks for the update I'm planning to install a all in 1 system myself but thinking about mpp-solar inverter
That's a good brand too.
Hi David,great video,I would like to request a video about total costing and economical reliability in lifespan of 1,5 or 10 years of time when compare to the cost of E Bill from grid,thanks
Would it be possible for you to set up the growatt inverters with grid on the inputs and program them for solar priority with battery as secondary? Then using solar as primary charging and grid for secondary charging. I have 2 of them and the auto transformer as well. Curious to see how well they handle the priority transfers. It seems logical to have the grid connected if it’s available but not use it unless necessary. The internal switching capability seems to make these superior for the price.
It looks like the application of autotransformer by solaredge hard wires it in, but then uses a two pole 25A breaker for the mains to the backup load. If you had all load on one leg that would still be 25A@240V transformed to 50A@120V=6kw, So I don't get how that's safe.
I'm keen to ask some breaker manufacturers if one can gang a =63A (~15kw@240v but assuming there is a main breaker acting as the wiring circuit protector) circuit breaker, since they design all their single poles of at least the same rating to be "gangable" because they also manufacture them that way, I would assume they probably try to use the same force specs across the board to trip the breakers.
Great 1-month update. I'm happy with my current one-inverter set up (with LI battery strings) to power all the essentials (all power plugs, lights, computers, modems, ...) and planning already the expansion to two parallel inverters with additional LI battery strings. Understand you are using program US2 (LI without BMS communication). I tried for two days to get the US2 settings right and then switched to USE (acid lead) program with the following settings for programs 12, 13, 19, 20 and 21 ==> 51.2, 53.9, 56.4, 54.4 and 44 what works flawlessly ever since for me. May I ask you for sharing your settings to see if I can get it working under US2. Thanks in advance. Anyway, there should be a kind of database where one can share those settings, as it is of interest to many.
I set mine to: Bulk 56.0V, Float 54.0V, and LVCO 48.0V
@@DavidPozEnergy Thanks, can you confirm these are the setting values you use in US2? Any insights on using US2 over USE? I do not see where the practical difference is, besides the LI symbol is flashing as it has no data connection to the BMS. Thanks
So interesting this work
Not a fan of the autotransformers and dealing with Neutral and potential ground loops. I like the all in one units that provide 120/240 like the MPP Solar 6048 units - each inverter provides both 120 and 240 even with just one unit, and they parallel together to get 12kW (if 6kW is not enough). For me the four wire set up (grd,L1,L2,N) was a real plus, and no autotransformer needed. Wires right up to a subpanel with no N-Grd bonding issue.
Could explain the neutral to ground bonding from your auto transformer and how you isolate it from the grid ground, thanks for sharing.
Yeah, I have that same question...it's all the same ground as I see it?
There is no need to isolate ground or neutral because it is an autotransformer.
Unlike a standard transformer, an autotransformer creates a direct connection throughout - it can never be isolated by design, so there is no reason to try to fully isolate the primary and secondary sides of the system at all because it's impossible.
If you need/want an isolated system, you have to use a standard transformer (not an autotransformer) with each side electrically isolated (meaning wholly separate conductors including separate neutrals on each side and separate grounding stakes a good distance apart).
Just use a conventional, yet large, 2 coil transformer to convert 240vac to 120Vac, ur inverters they work in phase so each takes exactly 1/3 of the load (or half the load each if you use only 2 inverters). With a single trafo you get even on loading each inverter, only that trafo will be pretty big (12KVA trafo would suffice).
Whe using 2 inverters, final config, how do they both charge the battery ? also each gets half solar panels ?
Nice setup, all well done !
Any update on a safer way to install the auto transformer?
Hi! Great video! I bought two of these thanks to your videos and I am very happy with them. But I wonder if they will shift the power point if you reach the 5000w limit of solar panels, like they did when the amperage was reached on your panels. I have 6300w total on one inverter but here in Sweden the sun is really low so it only produce like 3000w. Have a great day and thank you for a fantastic channel.
Hi David. Thanks for sharing the good work you're doing. Is there any way you can assist me in building my solar station? I live in Houston Texas
David, I noticed you do not have anything connected to "AC IN" on the GW's. I am doing a similar set up with 3 GW's but I hooked up the AC IN on mine. I believe this allows the GW's to "pair with the utility if the solar is not enough to power a load". IS THAT CORRECT and how does that work? The way I did it is I disconnected my house main panel (making it my #1 sub panel with all my House circuits in it) and added a NEW 200A main panel. That New Main panel is dedicated for 3-50A breakers to power the "ac in" on each GW and 1-125A breaker to power the #1 sub panel (the house circuits). I added a 125A Breaker in the upper left of the #1 Sub Panel to work with a Generator Interlock kit and the 200A main on that box to separate the grid and solar powers. That 125A breaker powers a 2nd sub panel that is dedicated for 3- 50A breakers to receive power from the GW's "AC OUT" and 2-30A breakers for 2 - 5k Split Phase Transformers. I have a diagram of all this but can't load it here but it is on the DIY Solar power Forum. Just search member Jim Lee then "11.8KW Ground Mount and 3 SPF Growatt 5000 ES, Grid pairing and Generator. But will it work?" I would appreciate any input on my setup you could possibly offer. I believe a lot of people want to set up solar this way, but it's not shown how to do it anywhere that I could find.
Try replacing the case fans with notoriously quiet Noctua fans.
With a 5 KW generator 20 years ago 10 hours a day was costing me about 700 a month
have you created a video on how to set up the autotransformer to protect loads if it breaker trips?
hello david. great great content. i think i need your advise for a solar project. ive watched about every video you produced and you seem to have enough experience for a newbie seeking help like myself. would you?? i ask before i throw alk the info at you. greetings from copan ruinas, honduras.
I'm trying to understand the part about, changing the midpoint inverter setup. Are you planning a video on that?
Do you mean about adding the auto-transformer to make a neutral? I have a video on that topic: ua-cam.com/video/yWUfvvSa3K8/v-deo.html
@@DavidPozEnergy I saw that one already, but during this Video you said there is a better way. I'm wondering what is better and will there be a video on it?
Leave that third one, because you will prolong the inverters life span, you will increase the load alot on only two if you reach the peak of 10Kw
Nice video and because of your videos I bought the same model. I’d appreciate it if you tell me which setting you adjusted for the charger to back off to avoid micro cycling. Have a nice day and wishing you the best.
Looks like Auto transform was designed to have its heat sink at the back and dissipate heat as natural convection;
Can you please remove the device/obstruction right at its bottom to allow for free airflow ?