Safety Concerns with Auto Transformer and Growatt 240V inverter SPF 5000 ES

[@philstreeter9703]

David, Don't apologize. Your very transparent and safety conscious. Thank you for all of your videos. It's always a pleasure to watch them and learn from your DIY attempts. Sometimes your right and sometimes your wrong and you inform us as to why it was wrong, informing us along the way. Love your channel! Keep up the good work.

[@benssolarandbattery]

Thanks for showing us how to add extra safety into this setup. It's pretty scary when you lose a neutral!!

[@benssolarandbattery]

@Patrick Baptist not really. You understand why it's there, right? It's in case the neutral is overloaded, but shuts down the entire system to protect you.

[@benssolarandbattery]

@Patrick Baptist last bit here. The hot side is protected as well in multiple places. The neutral breaker is meant to prevent overloading of the wire AND autotransformer. It shuts off everything to prevent a lost neutral. Have a great day.

[@silicon.alchemist]

@Patrick Baptist You, sir, have no idea what you are talking about. All of you arguments are based on the operation of the LOAD side of the system. All of the stuff on the USER side of the breaker panel. This situation is on the SOURCE side of the AC, like the mains connection to the grid. This is the generator side of the circuit, and so interrupting both phases and the neutral cannot have a safety issue because it's on the source side of the panel and not the user side. The user side still has neutral bonded to ground in the breaker box. Thus, it doesn't matter if the neutral is disconnected, since the hots are both disconnected as well. Consider that 240V appliances don't even have a neutral connection, and they have no resulting safety issues... If you think about it, a neutral wiring fault where the neutral is completely open, is not dangerous at all. There is no complete circuit, thus no current flow, and so no danger. All appliances are either double insulated or grounded to prevent the user getting exposed to line voltages. Where it does become dangerous, is a partial open or poor connection on the neutral (or hot, for that matter). This may result in overheating of the connection, causing a fire. An open ground lead on an appliance equipped with a ground is a much more dangerous situation. As far as your bus (what the heck is a metal endorser???) is concerned, the skin and all other metal components should be properly earthed to bleed away any fault currents from bad wiring, but this has absolutely nothing to do with the AC neutral. Classic power distribution systems have a transformer on the power pole to step down the high voltage distribution network to the typical split phase 240/N/240v connection to the consumer breaker panel. This system has the neutral and the ground points of the transformer secondary connected together at the transformer, to ensure the neutral does not have any voltage on it, except for a bit caused by current causing a voltage drop in the wire. In a typical home breaker panel, the neutral bus bar and the ground bus bar are both directly connected together thru the metal enclosure. This ground net is then connected to a good earth ground inside the structure such as a water pipe or long grounding rod driven into the earth. So, loss of the neutral on the incoming power side, while not a desired situation, does not result in any immediate safety concerns. Since there is no power to the panel, nothing is going to be powered, so there is no concern about hazardous voltages on the loads. I think this is actually kind of redundant, since if there is no AC present on the two phases of the incoming AC, there is no reason to assume there will be any voltage on the neutral either. The autotransformer is just used as a divider circuit to ensure that the neutral always remains exactly halfway between the two phase voltages. Since they are out of phase anyway, this works just fine. It is prudent, however, to address the possibility of a fault on the autotransformer. If one side or the other develops an internal short, the autotransformer could start to draw excess power from one or the other of the inverters, and cause an imbalance on the system, possibly damaging 120v loads or the inverters themselves. This system relies on a large circuit breaker to interrupt the power, which means the fault current has to be large to trip the breaker. By the time the fault current gets to this value, damage has likely already been done. There should be a way to apply GFCI technology to this situation, which would provide an extremely fast trip and protect everything, without relying on huge currents for tens of minutes to trip a breaker. This would be a topic for some research.

[@BecomingOffgrid]

Losing a neutral is more serious than frying electronics, It could burn your house to the ground. I’m really happy to see you doing something to increase the safety of your system David. Great job

[@uhjyuff2095]

Does a circuit breaker protect against losing a neutral connection? I don't know why losing a neutral could burn my house down unless these inverters have incorrect wiring configuration because they are made for EU grid systems!

[@BecomingOffgrid]

@@uhjyuff2095 Simply stated, the neutral is a balance lead that is trying to stay at 0V. Without this balance lead, your one of the hot legs could have a lot more (or a lot less which is also not good) than 120v if the loads between the two hot legs were unbalanced. For instance if you only had devices turned on using one of the two hot legs, it would be getting 240v because the balancer that would keep it at 120v is lost or not working. It would surely catch something on fire to operate 120v devices at 240v. You should probably watch some youtube videos on what happens with a lost neutral. kzbin.info?search_query=what+happens+when+neutral+is+lost Circuit breakers (OCPD) protect against overcurrent only. Hence why they are called overcurrent protection devices in the NEC.

[@uhjyuff2095]

@@BecomingOffgrid hmm, you flip flopped because I replied to your comment? Does the addition of a circuit breaker on the neutral conductor make his home more safe? I think you will say yes, so please tell me why? My home doesn't have a circuit breaker on the neutral conductor!

[@timbensing1075]

@@uhjyuff2095 the addition of the circuit breaker, only protects the transformer from being overloaded. It doesn't provide any protection for the 120 volt devices. They can still be damaged if the transformer fails.

[@urbingwatched9752]

Greetings, First David thanks for the videos and please keep them coming. In a nutshell here is how I plan to hook my 5000ES and AT up. The 5000ES output will go directly to the AT. From the AT I have L1-N-L2. The L1 & L2 will flow into over Amp breaker 20 amps (5000/240). From there the L1-N-L2 will flow to an over/under voltage breaker. Thus L1 to N or L2 to N drops/exceeds 10% of 120v the breaker will open. From this breaker, it will flow to an auto transfer switch between the inverter/AT and the grid ... Actually 3 of them 1) house critical 2) house non-critical 3) barns. This will allow completely bypassing the inverter/AT for any group. Each ATS will feed a sub panel. Neutral and earth ground will not be bonded in the panels, with the earth ground of sub panels, inverter, AT connecting back to my grid panel and bonded to neutral there and to ground rod. I also plan to feed the grid via a breaker from the main panel to the inverter to allow charging batteries. Please let me know your thoughts.

[@tincankiller6454]

Thank you David for this video looks like you have chosen the best solution for a least likely problem, but we all know s--t happens. Stay Safe & Good Luck

[@Tumbleweed5150]

Hey, David. There can be no ground to neutral bond in the inverter because there is no neutral until it's connected to the transformer. What you have are (from left to right), ground, Line 1 and Line 2. Great idea putting the tripple breaker in so that everything except the earth ground connection is broken in case of an overload. I will be looking into adding that into my own system, which I built after watching your video on the origional 3 Growatt install.

[@jeremyallard5449]

Wouldn’t it just be a better selling point if Growatt got their finger out and provided the correct CCT diagrams for all territories. It would be good if Signature Solar made this a term and condition of purchase and supply, and we’re mandated to sell the ES models with proper instructions from Growatt.

[@timgerk3262]

That is the better solution. Better than educating North American professionals and DIYers how 240V systems work elsewhere, so they understand what is the real expected operating condition for Europe/ANZ/China equipment. Removing bonding jumpers and shifting the earth reference potential in these imports is ... messy. (Also, KZbinrs being clear what their national context is.)

[@sandracoleman1330]

I am in the process of contacting Signature Solar to buy a Growatt 12 and a 5 and was so worried after seeing so many videos about the problems now thanks to your video I feel better. I will be using it off grid in Arizona.

[@dr.projectx5142]

This is very neat. Love the content on this channel. Plan on doing a set up in mexico with 2 of these and use a 120v to 48v charger to charge up the battery and run off the inverter with the auto transformer to have 120v. Since there is just 120v at the house and want to add 240v ac for a small ev. Or for when the power goes out. Will be great for setting up and also for welding as well. Keep up the great work. 👍

[@markfletcher6511]

I have three of these inverters. 50kwh of battery. I connected 240v from the grid for a supplement to my solar generation. The third inverter has a connection from my generator as a backup to long term grid down and rainy days. The connections for all of the inverters includes the earth ground (green) from the grid powered panel. That same green earth ground is connected to the load panel. I hope that this insight helps. Note that this installation does not back feed to the grid in any way.

[@trueamerican1576]

How are you controlling the neutral so as to not run through the neutral from the Transformer to the grid?

[@lloydrmc]

Bravo! Excellent way to enhance safety and optimize output.

[@thepricelife2374]

Great video! Something to consider that is not covered in this video. If the Neutral for some reason is overloaded then it will trip L1 stopping power to the panel, this is only effective if there is an overload condition on the Neutral. However you still have a breaker for the Autotransformer in your panel. If for any reason that breaker is tripped, you will lose your Neutral, and not trip the triple breaker you installed. You will then have 240v across the panel with no neutral. To possibly solve this you could use a 2p+2p Quad Circuit common trip Breaker, tying the Back Feed breaker from the inverters to the breaker for the Autotransformer in the panel. In this configuration if the transformer breaker trips it will disconnect the Inverters from the panel.

[@sloup000]

Just added the terminal and 3 pole breaker, works like a charm! Thank you very much for posting this video.

[@rob1andrews]

Love you continuously improving setup. It is all getting pretty complicated, consider creating a schematic diagram for the whole system!

[@bjmurrey]

appreciate the update and the videos! Signature Solar is thankfully a short drive from my house I discovered! Planning a visit soon to buy a couple of inverters!

[@DSmartLife]

Thanks David for updating that your setup is safe, was worried seeing the issues pointed out by others. But I still want to mention to those who are using these inverters directly imported from China and/or are having grid connected systems should be very careful. Those who have grid connected systems can burn up their autotransformers/wiring if connected without a dedicated transfer switch. And then there is the neutral ground bond safety issue in grey market imports. Lots of potential for failure and safest hazard. Be-aware!

[@isovideo7497]

Signature Solar GroWatt inverters are the ONLY ones with the ground-neutral bond broken. ANY other GroWatt may be dangerous if used with an auto-transformer.

[@hdeberry9870]

David, after watch your videos over the past year, I purchased 2 Sol-Ark 12k 48V inverters and 6 gyll 48V batteries along with 40 410w Mono Bifacial Split

[@georgedrenes8143]

Thanks for making this video, David. It answered a lot of questions. I went the route of getting two auto transformers to go with my two spf 5000’s and hope to finish the wiring today so I can try out the system. Your effort’s to make these informative videos are much appreciated!

[@DavidPozEnergy]

That's probably a better way to go. Nice.

[@JamesLee-ey2yv]

George, I got 2 auto transformers also. Did you get the solar edge or growatt transformers. Would you tell me how your wiring them. I know how to wire up one, but I'm a little confused about doing 2. Do I or can I wire 2 the same as one using separate breakers or do I have to combine them together into one larger breaker.

[@SpiritBearRanch]

@@DavidPozEnergy I'm interested in building a system for my cabin and I am on a fixed income what will it cost to get a setup

[@curthatton3395]

Hi Mr. Drones. Like Mr. James Lee I too have purchased two SPF 5000 ES Growatt inverters AND two 5K auto transforms (one SolarEdge and one Growatt). I'm looking to learn how others with two auto transformers have wired them when using two SPF 5000 ES Growatt inverters. I haven't installed any of my system yet. FYI, I have four 48V 100AH EG4 Lifepower4 batteries, and 10Kw of PV panels. Any information you wish to supply would be greatly anticipated. Thank you. Know anything of Mr. James Lee's system?

[@curthatton3395]

Sorry, Drones = Drenes.

[@CraigThorne]

m liking this setup for your auto transformer and load connections. I felt a bit uneasy without having the whole thing switch out if one portion had a problem. Well done!

[@CraigThorne]

Wow, if that doesn't look bogus! I got a reply from someone/something with David's face but a instagram url.

[@ericzaddock]

I was wondering when you were going to weigh in on this issue. Thanks for making the video.

[@uhjyuff2095]

Yep! all fixed installed a circuit breaker, LOL. Circuit breakers are the NEC standard for overcurrent protection, but he didn't solve the underlying issue this inverter/autotransformer system has in regards to safety and when connected in a inverter and battery charger or grid bypass mode!

[@CaptBill69]

Interesting to see the response to Will Prowse's recent heads up clip, and learn more from response clips, plus comments. I warmed up to idea of using a European standard GroWatt with a autotransformer when I learned one can get full inverter power to either leg of 120vac in a 240vac circuit breaker box vs maybe half that max to each leg from same size inverter designed for USA split phase 240vac. On the other hand: I agree with Will that modified GroWatts ... with the same model number that can be different without the buyer knowing what is up, is terrible. AND I hope GroWatt addresses this situation, including with detailed wiring diagrams for powering up USA 240vac split phase circuit breaker boxes. Glad to be in a Learning More All the Time Mode :+)

[@douglasgreenwood7002]

Can you send me a complete wiring diagram from both inverters transformer to the main panel along with grounds. I’ve Bought the exact same system for my off grid cabins. I watched the video from signature solar yesterday And loved his explanation to the turmoil that was brought with the whole conductivity between the line and ground or neutral and ground. Anyhow I’ve enjoy your videos I pretty much just Copied exactly what you’ve done. I love your content keep up the good work.

[@wellsleonard5006]

David how you doing this is Leonard Wells is There anyway possible you can send me a complete wire diagram of both inverter and transformer to the main panel along with Neutral wire diagram. I'm going to try to duplicate what you done for my Off Grid living

[@jsmalone1]

Probably already a comment about this, but I have 1 5000 watt Growatt inverter and the same auto transformer. I also have an Emporia load monitoring system in my electric panel and I monitor the transformer neutral. I run my entire house less large appliances on this system. 2.36 amps is the largest load I ever recorded on the neutral. If it's a balanced load, little should be on that transformer. You can switch loads from one phase to another to balance.

[@MartinKL]

I'm glad you're improving your safety. Normally I'm not the fear-mongering type, but I have a friend whose house burned down because he lost neutral (on the utility side of his meter). So I know it definitely can cause problems and personally I'd do whatever I can to reduce the possibility of this happening in my own system.

[@easylooker]

So how is someone going to prevent their house from burning down from losing a neutral from the grid? I know a guy whose house burned down because of a grill. Another because of a lightning strike and not to mention those losing houses to wild fires.

[@llsncl]

@@easylooker lol, kinda missed his point there didn't ya?

[@easylooker]

@@llsncl ya I got his point. You missed mine

[@joelyalong1562]

Neutral carries the unbalanced current which exceeds 200percent of the line load current..instantaneous

[@big0bad0brad]

@@easylooker Really there needs to be an active fault detection circuit that shuts off the main breaker and I've never seen one in use.

[@excillisbank2611]

superbe démonstration DAVID, merci encore pour tout tes efforts de partage de connaissance.

[@brycestewart3181]

Great job, even one "opps" would more then pay for that protection.... Great Idea, Great work... Thx for the vids... Well wishes to you and yours....

[@8uhayat]

Ok so that makes much more sense now, I mean for me being on a 3 phase grid and system. Keep the amazing vids rolling David, no have no idea how far and away your knowledge is being spread 👍

[@flyingtools]

Hi and thank you for a good video.I am also using two of this for two month now and I am very happy with it, no problem whatsoever. Hopefully it will be some kind of standard how you will wiring this auto transformer together with the growatt inverter, so everyone will know exactly what and how they should do it when they have bought it from signature solar. Maybe then this wave of safety concerns will go away. I live in Sweden and have 220v so this kind of problem do not affect me, but it is interesting to see how you try to find a way around it.

[@buixote]

Might be interesting to add "autotransformer temperature" to your power usage spreadsheets...

[@CotyCondry]

Separate the 240v and 120v loads into separate breaker panels/boxes. Bond the 120v breaker box and auto-transformer, and connect them to the 240v panel with a standard 2-pole breaker. So if the auto-transformer breaker trips, it disconnects all power from the 120v loads.

[@makesaveinccomm]

Can you make a video for this please. thanks

[@TheFatman819]

@@makesaveinccomm kzbin.info/www/bejne/b2GykJx9n8ugaJo

[@CaptBill69]

IMO: This looks like an interesting option to test and track; says my curious DIY side with hands on house wiring and one MPP solar system experience, but no autotransformer experience (yet). Wondering if this would protect from possible lose of ground., And if not. If a ground fault type breaker might also be some kind of option. I admit I still do not have full picture of concerns.

[@CotyCondry]

kzbin.info/www/bejne/iKisaWZpjs1ojrc

[@uhjyuff2095]

@@CaptBill69 Interesting idea with the GFCI circuit beaker... I have always wondered why these portable solar generators do not have GFCI protection when they are mostly used outside which the NEC requires all outside receptacles to be GFCI protected. Also GFCI breakers are common with electrical hot tub installs although most are not 3 pole circuit beakers like what he is showing in the video.

[@michaelseah9617]

Nice video there. I have a small suggestion for you. I am in Vietnam, we get 210~265vac from the grid. Vietnam standard AC is 220 +/- 5%. I have install a 220→200VAC transformer at the grid incoming. So my house voltage is 195~220vac. Usually 209vac with my grid tie inverter. Cause most electrical items can function within a range. Everything runs fine. Plus a slight benefit of lower power consumption and larger headroom when surge occurs. Air-conditioning, freezer, fans all runs slightly quite. Dunno if this will get electrical economy at your country.

[@howardkearney7989]

Thanks David! I bought the growatt, auto-transformer, batteries, and solar panels using your coupon codes. I'm getting close to installing these soon. I stopped because of those "danger!" videos. But now I'm feeling better about continuing. I'm off-grid and am searching about if I need to ground earth or not. I saw some youtubes (Prowse and the NEC) saying things that got me confused. But it is fun learning this stuff!

[@firebird9232]

your better off buying the correct inverter for usa!! Not a eu version which you need to buy a ton of extra equipment to even step it down doesn't make sense. . Plus doubtful pass electrical inspection. Your house burns down and the insurances finds out you did electrical work without permit they don't pay out even if wasn't from your solar system...

[@howardkearney7989]

@@firebird9232 I believe SignatureSolar provided me the correct inverter as it the USA version. I'm good. Thanks.

[@ToddDesiato]

You could have installed a breaker with a relay contact for the XFMR, and a breaker with a shunt trip on the inverters. Then use the relay contact to trip the inverter breaker. That way, you're not breaking the neutral connection. I don't think it meets NEC code if you break the neutral with that middle pole! I recommend having a PDF copy of the NEC to consult before guessing. :)

[@eddietee6305]

Good point. Don't play with neutrals.

[@AleOle]

What an amazing guy! Keep on sharing all these with us!

[@Wingman77tws]

I do the same thing with my setup, two 5Kva victrons and a industrial 10Kva transformer I got off ebay to work as an auto transformer and provide neutral. Instead of complicated breaker system I just depend on the transformer being overkill and don't worry about it... haha. The 3 pole breaker though is a great solution. only issue being that the neutral and the loads have to be on the same current breaker. but its a great idea.

[@solexxx8588]

With L1 and N tripped on the breaker, L2 has no current path at all. You would have to have a second failure for the L2 to find a path to ground.

[@nb117]

Which Transformer did you buy from Ebay?

[@JamisonWorkshop]

Like your ingenuity on getting things correct. Unfortunately I am a bit OCD on my wiring and would love to see you have things tidied up once you have wire locations sorted. That would drive me nuts.

[@darrenbenson2606]

It’s amazing how much cleaner the power is from my Growatt inverter than the grid. My washer makes weird noises when on grid and is quite as a church mouse when off grid. I’m going to have my house disconnected from the grid next month because my power provider won’t work with us if we have solar.

[@TheFatman819]

Where is this happening? The unit is Pure sine wave, you should not be getting that much noise from the power company as they can shorten the life of your electronics and refrigerators and such, have you contacted them?

[@firebird9232]

sounds like bad transformer on the pole.

[@CaptBill69]

Curious what your grid location is. ... like city or town, state, and country ???

[@sloup000]

Since these don't back feed to grid what us the issue with power company?

[@johnandrews9433]

@@sloup000 doesn't matter, some power companies don't want anybody with their own source connected. Probably for liability from the dumbasses who do back feed

[@Time-Trvlr]

Your water heater CB top wire should have some red tape on it to indicate its a L2 wire and not a white neutral. thanks for keeping us updated.

[@justaguy-69]

good solution, even tho you doubt you would need it better safe than sorry for very little cost!

[@baknblack1]

David, could you possibly do a rough drawing of all the wiring?

[@BillSampson]

This video and all of your videos on Solar setups for off-grid have been very helpful to me. Would you please provide the terminal block information.

[@bigblockcutlass123]

Good job David, Thanks

[@kenglass2121]

Thanks David for everything

[@zweriuskriegsman]

David, I think it woulkd be very informative, if in the beginning of your video's, you would be showing a schematic of the current situation and of the changes / new situation.

[@swaterman08]

in our office, each section of cubes uses 3 to 4 circuits. They will use metal clips that connect all the breakers together making them a single handle.

[@jquarshieful]

Very impressive, keep up the good work

[@MsMicke75]

all respect and appreciation

[@jasonlaughrey6880]

Just a suggestion, you could install a phase monitor. If you lose a leg of power it will trip or if there a voltage in balance it will trip.

[@DavidSelf3]

Love your videos David, thank you for sharing!

[@McCuneWindandSolar]

when you showing the parrelling of those Growatts. they are pretty much the same thing as the MPPT inverters I have.

[@harryv6147]

If you are using these Growatt 240V SPF 50000 ES units connected to the grid there are other hazards to be concerned when using a auto transformer on the output of these units. I believe your safety measure completely cover your off grid installation as you show here.

[@MrSummitville]

These are *not* on the grid.

[@mendohomepower7492]

Excellent!! Good solution.

[@andreiacarvalho2340]

hi I'm in Brazil and I bought two growatt 3kva because I was afraid to use a transformer in my circuit. I am not an electrician and I preferred not to take the risk. But watching this video I think I made a mistake because it's practical there's more Kva

[@stevebailey1682]

David...it would help if you supplied a schematic of your setup for comment.

[@danielking2944]

I have two of them connected to a mid-point.Also have them with grid-supplied disconnects.Works fine.They share a battery bank with a MPP6048 .I usually leave the ac input to the Growatts turned off.They are loaded primarily in the daytime for electric dryer and help maintain the battery as a secondary gig.

[@eDoc2020]

If you have a midpoint transformer connected across the pole transformer from the grid they will short out each other's neutrals. In a perfectly balanced system this won't cause any problems but in reality it can lead to excess current draw.

[@RolandW_DIYEnergyandMore]

David. In your 100% Off-Grid solution, you will not have any troubles with that system. The 3-pole breaker should work, as long it can be made to trip in the first place, as you know, that MCBs do need a bit of an extra current to trip for overload. I do not see the need of using isolation transformers. Non-internally or externally N-G bonded inverters are IT (isolated) devices. An N-G bond after the autotransformer will give you the safety features of a grounded grid-connection.

[@uhjyuff2095]

This is a floating neutral solar generator design, I don't believe it can be used as a bonded neutral type generator because it would not be safe. Many portable generators (Honda inverter generator) are floating neutral designs and I wonder how safe those are?

[@justinz371]

Each invertor is suppose to have 8 awg and a 50amp 2 pole breaker. If you are taking the wires from the term block to the ac distribution pannel, you need to up the wire size and to a 100 amp breaker.

[@Gratefulwon]

Maybe start the video with what a autotransformer is and why you needed one?

[@McCuneWindandSolar]

I see you all used the auto Transformer. I just used a 240 volt transformer. The one I have has a 240/480 in and 120/240 out put. I have the MPPTsolar inverter that is 240 out put, I ran that to my transformer and then the out put is still 240 volts but I can use the Split phase to get 240 and 120 volts. and then ran that to my Breaker panel. My Inverter was still connected to the grid just only need put wire it to the 240 volts. I never had a problem with that set up.

[@petrag.4092]

Thanks for sharing!🙏

[@RS-lt2ue]

Well done Sir!

[@zember3990]

David Ted Embner Here from Canada Just one let you know i like your KZbin Chanel But my friend you have to do more proper set ups like proper cable proper set up syastems i think you will be much popular Best regards

[@leoschneider3570]

With the problem with if the breaker for the auto transformer turned off, one idea is to put in a relay for high amp split phase and have its coil energized by the auto transformer’s breaker, and have the relay switch the inverter’s output, so if the breaker trips or is shut off, the power to the inverter breakers will get killed

[@stuarthelgerson403]

Another super informative video David, a great solution to the overloading worry. So are you running the ground on the inverters to the ground in your main breaker box and is the ground and neutral in your breaker box bonded? Much thanks.

[@eDoc2020]

Yes, that is how his system is set up.

[@diysolaradventures7894]

@@eDoc2020 what if ur inverter only has two outputs L and N no ground except a grounding screw on the case can u run the ground from that screw to the inside of the breaker box ? and when ppl do all this case and inner grounding what about a grounding rod where does that come into play ??

[@eDoc2020]

@@diysolaradventures7894 You're asking too much to answer in a KZbin comment. I suggest you look into the local codes applicable to your area as well as the instructions included with your equipment.

[@jsmalone1]

There seems to be many people raising concerns about Growatt inverters. Mine has a 240 volt feed from my utility connected. You do not use a utility neutral nor their ground. This is not a concern. It is simply an electric source, 2 hots. As a 45 year career commercial electrician managing large projects I can attest that: 1. You will get 10 different opinions from 10 electricians. 2. Most people do not interpret the code accurately. 3. The bad or incorrect wiring methods electricians use are many. Ask any project manager, job superintendent, like me or architect. Habits and gossip are the drivers of this. I saw a video of a man claiming how dangerous these inverters are. Nothing he claimed, with a meter btw, was accurate and I could not replicate what he claims. Different inverter?? I don't know. I have 2-- 5000ES Growatt inverters, 1 for backup. I run my entire house, less dryer and AC. I have a heat pump water heater that draws almost 400 watts. It's on my system. I monitor everything, every load, temps. So with 1 inverter, 4,400 watts installed solar and 23kwh of battery, my system is essentially idling most of the time. My system produces more than I use. I built this system for back up generator purposes btw.

[@uhjyuff2095]

Everything is all good as long as the autotransformer never fails. Your 240 volt loads work great from this inverter, but what happens to the 120 volt loads if the autotransformer fails? If a isolation transformer fails, it will short circuit and trip the main breaker and save your house from a melt down, the autotransformer fails no breaker trips and your 120 volt appliances are now 240 volt? I probably have no idea what I am talking about, just something for you to think about. I don't have a 240 volt inverter, I chose to stick with a 120 volt inverter because I only have 3000 watt solar array.

[@timbensing1075]

I can confirm that there are two different inverters being sold in the US, with the exact same labeling. Signature Solar was out of stock, when I was ready to purchase. So, I mistakenly found what I thought was the same thing on Amazon. The 240 volt leg , identified in the inverter as "N" is bonded internally to the metal case of the inverter. It cost me a few appliances. I tested it for bonding and didn't read continuity. I figured out that it is only bonded when the loads are powered through the inverter. I have sence corrected the issue on my inverter. But, no longer have a warranty. I am a 37 year electrician. With experience in residential, commercial, industrial, mining, and marine wiring. This one fooled me. Please everyone, make sure that you are buying the US version, if you are in the US.

[@emilywilde2348]

Thank you!

[@modjoetv4440]

Thanks for Solar power related videos. I wonder if there is an inverter that draws electricity from grid once your battery cannot accommodate the household current but it does not share the excess electricity to the grid?

[@joe7272]

Essentially you are using a neutral current sensor to break the entire circuit in case of a 120v tapped circuit becoming overloaded. This sounds extremely safe and is solved with a somewhat standard electrical part. You should try contacting the vendor of the ones you wanted to join. I'm sure they have an answer.

[@mkonvo]

Thanks for the info! I am currently working on building a similar system. Question, how does the system handle the well pump and water heater at the same time?

[@DarrenCharron]

I am not an electrician but I do think adding the extra triple pole breaker is a good idea.

[@DSmartLife]

Yes I think it's a good idea. However the 32A breaker for 32A capable transformer. I don't know how long it will take to trip the breaker at 32A. Which will be faster, tripping the breaker or over heating the transformer? David's last video showed his breaker tripping only at 1.5 times load or something. So we need to confirm the Trip curve of that breaker, or decrease the current rating of the breaker.

[@TheFatman819]

kzbin.info/www/bejne/b2GykJx9n8ugaJo. Signature solar explains everything

[@timbensing1075]

@@TheFatman819 not this, yet

[@DaleKlein]

The names or labels of the AC output of the inverters: you're calling them L1 and _neutral_, but aren't they really L1 and L2? Ie: 240vac between them. So, when/if the new breaker trips, there is still 240vac present in your whole house on the L2 (being called neutral)?

[@georgemouer4565]

Exactly ! There is NO neutral on a Growatt 5000ES, 240 only (2 hot legs), that is the entire reason the auto transformer is needed !

[@solexxx8588]

He did say that at one point. The in and out of the inverter are L1,L2,G The AT has L1, L2, N, and G.

[@eDoc2020]

As the inverter outputs are isolated from ground, there won't be any voltage between L2 and G unless L1 is connected.

[@anastigmatix4119]

You really need to draw a circuit diagram of the AutoTransformer to make sense of this.

[@paintasylum8315]

Ok. What if in between the transformer and the breaker, you add two buss bars for Line one and Line two. Then wire from the 30 amp breakers to each bus bar and from the bus bars to line one and line 2 of the autotransformer. This way you can wire your 120 loads to the buss bar. If the breaker shuts off shuts your loads off at the same time

[@gringoloco22]

I don't think anyone has really explained how the breaker tripping would cause a power spike. Since the autotransformer will loose all L1 and L2 poles from it and the 120V volt loads would only be connected to just the dead neutral and one leg and ground.

[@captainobvious9188]

Tripping the breaker to a separate auto-transformer? The circuit changes from two essentially separate circuits (current paths) into one circuit with the loads on each leg now in series. The leg with load (the higher resistance) now has a higher voltage potential on it. If imagining the water/pipe analogy of electricity to understand it, where volume=current and pressure=voltage, the leg with the lesser load becomes a "bottleneck" because it can't flow as much volume as the other leg, so then the pressure builds up on it. For example: Say you have 240V total, with 120V on each leg, with 1000W load on one leg and a 500W load on the other leg. Those would correspond to approximately 14.4 ohms (with 8.3 amps) and 28.8 ohms (with 4.2 amps) resistance values. If you loose the neutral, now you have 1000W in series with 500W, or 14.4ohm + 28.8ohm = 43.2ohm with 240V across it now, able to move approximately 5.6A through the both of them (notice this is in-between). This means that there is now ~80V across the 1000W load and ~160V across the 500W load.

[@gringoloco22]

@@captainobvious9188 that would happen if you lost the neutral from your power company since you're connected to both legs still, but how does this happen on this set up when the 120v devices only have one leg and a ground? Does the power flow from one leg to the ground? If so is that even something that can damage devices?

[@captainobvious9188]

@@gringoloco22 I'm going to assume you're referring to ground as the assigned electrical ground, as in "live wire and ground". You are the power utility in this auto-transformer setup. So it would be like loosing neutral to the utility, or more accurately, it would be like the utility disconnecting neutral from the neutral wire as well as the ground. So the only possible current path at that point is through one leg across the shared neutral bus connection in your panel and then through the other leg.

[@gringoloco22]

@@captainobvious9188 Thank you for your replies, but what I was mentioning is that when the autotransformer breaker trips it looses L1 and L2 so I was confused how else it would cause issues with nothing going over the transformer.

[@captainobvious9188]

@@gringoloco22 Ohhhh, I apologize, I misread. When it breaks in this new scheme it disconnects the inverters as well, so I'm with you, I don't know why there would be a power spike?

[@CDNguyen59]

David, since 2014 till Nov 2021 I used MPP solar, but since Nov 2021 till today I have the same setup you have, but I didnt install my autotransformer yet, I got it seat in side my garage since, I have my system go thru a 10KVA industrial step down transformer, it working fine for me since 2014, but one of these day I will replace my industrial transformer with the autotransformer, I do hook my inverters to the grid, last Dec 2021, winter time during the day my battery bank does not got charged up, so at night the ATS inside the inverters switch to the grid to charge the battery bank, I also bough my thru the Signature Solar, I am looking to buy the 3rd one to use for solar charger so I can disconnect my Midnite Solar charger, the other reason I have my hookup to the grid, my house 100 persent electric, I have no gas, so during the winter my electric furnace does kick on every once a while when the fireplace no produce enough heat

[@frankz1125]

You would be surprised how many people do not know what electricity is and want to be off grid. LOL

[@jrscott5827]

Sir David thank you for your great coverage this is sincerely awesome for the hard work that you put in the videos are priceless I'm not electrician so bear with me on this question of all the fine-tuning you do and working out the bugs of these solar systems the whole purpose is for......1 off grid system number one works well with ABC or d off grid system number two pairs well with a b c or d and off grid system number three does not work well with ABC or d and off grid system number four do not use this combination or we've noticed these components does not work well with system package number one two three or four now......

[@douglasmarquis3446]

David, after you turned off the three pole breaker, you measured between L1 and L2 at the 50amp breaker in the panel and had no voltage , then measured L1 to neutral and L2 to neutral and had no voltage. OK that is good but you need to measure L1 to ground and L2 to ground in your panel. I think you will find voltage between ground and one of the legs ( L1 or L2 ) I am interested in your results.

[@SmallVansBigWorld]

Right, that's what I was thinking. The breaker is killing only one of the legs. Does the inverter still supply power to the other leg? Not really clear on this being a solution.

[@eDoc2020]

That would be the case if the inverter outputs were ground referenced. Here they are floating, meaning you need both legs connected for any current to flow.

[@solexxx8588]

L2 is not connected to ground in the panel in any way. Your point is moot. L2 has potential but no return path since N is disconnected when the breaker trips.

[@douglasmarquis3446]

@@solexxx8588 Ok , but why does David have a ground wire running between the panel ground bar and the inverter AC out ground terminal? Bounding the case to ground? Why if it has no potential to L1 or L2?

[@timbensing1075]

@@douglasmarquis3446 all non powered metal, such as enclosures. Should be ground bonded together. To reduce their potential to zero.

[@billjohnson3344]

Typically you would not put a circuit breaker on the Neutral, since that is also at ground potential and you don't want to loose that voltage reference across the system. Think of your typical grid tied electrical panel. Neutral is a permanent connection, and the main 200A breaker only switches the two hots phases. Not really a good idea to have anything that will interrupt neutral. Also, your setup of interrupting only one hot leg could still develop a voltage at the loads depending on the system grounding - which is not clear in your setup. Your neutral everywhere in your house can rise up to something other than ground potential - if the ground to neutral bond isn't in place. In your case I'm assuming you are ok as this connection is still at your main panel (with ground rods), but that really needs to be clear as that isn't shown in your video and is an important part of a safe system - on grid or off. The normal application of this autotransformer (with the StorEdge inverter it is designed for) does nothing with any circuit breakers isolating the transformer. It is permanently wired to the inverter. Proper safe operation in ensured by the temperature sensor in the transformer, which connects to the inverter and shuts its power output off if there is a transformer overtemp fault. You should really do something similar. Also, for grid tied setups, the autotransformer is also only switched in during islanding mode. SMA's autotranfer/autotransformer box works similarly - Enphase gateway, etc. Interesting what you are trying to do (and better than you started), but even as you have things know this would not be considered safe or legal from an NEC electrical code or UL standpoint - just for you and your viewers info.

[@solexxx8588]

If the AT fails from an internal failure or shorted N then the breaker trips N and L1. L2 has no current path left even if N and G are bonded in the panel after the breaker. Remember N is gone due to the trip and L2 is in no way connected to G. For any current to flow, you need a path and David's solution removes any current path. Think about it.

[@billjohnson3344]

@@solexxx8588 Correct, need a current path. But as only one hot leg is being disconnected, the other hot connection is still going to all the loads. The issue arises from the sketchy grounding of the 5000ES or any other international inverter used in the US - which may or may not be bonded internally to the inverter's so called neutral (which is this case is a used as a line output). Depending on how the overall grounding connections are setup, you can still develop a voltage potential at the inverter chassis and downstream. I agree David's setup would not incur this, but others using this inverter and not understanding system grounding may.

[@eDoc2020]

@@billjohnson3344 Yes this would result in hot wiring downstream if the inverter had a neutral bond. As David showed his Inverter does not have such a bond. In fact if it did there would be a short circuit anytime the autotransformer was connected.

[@joe7272]

I'm always glad to see safety content. I asked Will about a video on repurposing EV batteries, but he said it was removed due to the huge safety risk!

[@kevinhawthorne5257]

Great Video!

[@vickipps6821]

Great idea 💡 fortunately we don't need to do this as our power is 230volts question how many solar panels do you use and what type

[@huysworld701]

thanks for the great video David, May I ask did you bond Neutral and Ground in your breaker panel? from my understand the Growatt has internal bond N-G when power from battery, since your are running 2 inverter, are there 2 bonding already? thanks again

[@shawnterry6789]

David, I'm not sure if you have already done a video about this, but do you have a video about how you connected your subpanel into the main panel for your house. I imagine it's fairly simple, but wanted to see what others have done successfully. Thanks in advance for any assistance you can provide!

[@johnturner7060]

Why use a 32a breaker? 32x120=3800 and the inverter is 5000 w Growatt suggests 50a? Thanks for your work! It really helps!!

[@MrSummitville]

7,680 watts (each) = 32 amps x 240 volts

[@johnturner7060]

@@MrSummitville Thanks!

[@earthenergyhex]

Personally, I think electricians are the worst when it comes to commenting. I would like to see their systems if they have one. I like your channel and you know what youre doing. You had Ben over, a professional solar installer! If something was wrong or dangerous he would have told you. Now you want to see a hacked, dangerous system come see mine. LOL It works though, so I am happy

[@benssolarandbattery]

Hey, I'm an Electrician too! Haha. You've seen my systems most likely. I try not to comment unless I have something somewhat constructive to say...

[@solexxx8588]

@@benssolarandbattery Correct me if I'm wrong but with David's solution even if the AT melt's (bridges the transformer) then the still connected L2 can't go anywhere. With the breaker tripped there is no neutral in the panel and no connected path to ground in the panel Both L1 and N are open.

[@timbensing1075]

That's correct . I'm also a 37 year electrician . These videos are very informative. And, David's system is safe. As long as he is the only person messing with it. He has enough knowledge, to do what he does. While many parts of his system wouldn't pass an inspection. I would be obligated to warn him, if I thought it was dangerous.

[@usa-ev]

Nice job.

[@redneckways1617]

Your appliances would be burned up before the breaker is overloaded…better way to do it would be to replace your 3 pole breaker with a 2 pole contactor with a 120v coil…then if the neutral drops then so would the power…

[@benssolarandbattery]

But why?

[@DavidHalko]

@@benssolarandbattery - “But why?” In a previous pair of videos, that he is responding to, if the auto transformer fails or if a breaker snapped (intentionally by a switch off or unintentionally due to load) that the auto-transformer was plugged in to, one leg would jump from 120 to 249v a blow up half your junk. The poster tried to reference those videos with his comment, “Your appliances would be burned up before the breaker is overloaded” David Poz solved the intentional or unintentional breaker snap, blowing up equipment in the house… but did not cover transformer failure with this video. He hinted at it, with the relay & battery & thermo relay board, but he never completed the thought. There is still more to go, to make this a safe setup, with an auto-transformer. For equipment that has an auto-transformer built in, they have monitoring equipment built it, to keep an auto-transformer failure from blowing up half your house’s equipment plugged into A/C. (If you have a fridge get blown, this becomes an increasingly expensive problem.) The full isolation transformer is really the only safe solution… if the full isolation transformer fails, the equipment in your house is reasonably safe.

[@redneckways1617]

@@DavidHalko I didn’t respond cause those that don’t understand electricity would not have a clue about how to wire or understand why wiring a 2 pole 120v coil contactor would solve the problem…those without understanding need to hire someone qualified

[@DavidHalko]

@@redneckways1617 - a qualified installer does not remove all the risks of a system which has inherent risks. People must be aware of the risks

[@timbensing1075]

A contactor is an excellent idea.

[@fanaticosrc]

A good ideia for a video would be test how safe the parallel sistem is, one example: what happens if one of the inverters breaker switch off durring operation? Will the sistem shut down all the inverters?

[@stevelaminack1516]

Hi David. I have a 5.9KW solar system with one Tesla Powerwall. I am looking for solutions to add more battery storage. I don't want to adding another expensive Tesla Powerwall (if you could even get them). Do you have any suggestions/videos on the subject?

[@EddieSiembra]

I would also be interested in seeing a video on this.

[@willowoodherbals]

even though most of these connections I will pay someone to do, as I dont feel comfortable enough in knowledge to do... you are the first of the 90 or so videos I have previewed which show connecting to a double pole circuit breaker box... which is what I prefer to happen in my soon to be lived in off grid homestead. Thank you for confirming that can be done as I dont wish to string a bunch of extension cords to run lamps etc and have already wired to my interior plugs and switches. You are also the first person I have seen who has added a transformer? Is it required?.. please answer is it required.. no one ever answers my questions... going soon to move in a few months.. without any electric except generator.. as I cannot get a solid answer which company is the best to go with..

[@D2O2]

Great video. Any chance at a video demonstrating the the affects of the lost neutral?

[@JM-yx1lm]

Ian's projects KZbin channel did a video the other day demonstrate that and it blew the light bulbs. You just have to watch it to see if it's done right

[@DavidHalko]

See these videos: Video 1 kzbin.info/www/bejne/nYKXf3lvo5WIrqc Video 2 kzbin.info/www/bejne/naCpZWmtfNKDe8U

[@OurPassThyme]

Hi David, just curious about where you sourced the DIN rail distribution blocks for your L1 and L2 outputs from the inverters? Your videos have been super helpful designing my 12kw+ system. I think I have every piece except for those blocks...Thanks, -Tom (sorry if you mentioned it before in the comments, I've been digging through them but I figured it might be quicker to ask)

[@DavidPozEnergy]

Ebay. I found it using keyword "Terminal Block"

[@sorinsorin5134]

The dedicated grounding for Growatt is linked to output or input? I saw many variants, I guess are for output, for input has already grounding from the house, thanks.

[@solexxx8588]

Both in and out have L1,L2 and G

[@fisherus]

David, I am sure that you have seen Will Prowse's last 2 videos. He discusses how the European Union version of the Growatt has been changed specifically for Signature Solar and the US market. The downside is that others are selling Growatt Inverters to the US market that have not had the manufacturing changes done that Signature Solar has. Additionally, the manual that is being sent with the Signature Solar unit hasn't been changed to reflect those changes either. It could be catastrophic if someone bought a Signature Solar unit and piggybacked it with the EU version. Right now, both the Signature Solar version and the European Union version are stamped with EU. Confusing, yes? I sure wish that they had these types available before I bought my Sol-Ark 12K that I received in a 59V model that I still have sitting in it's box because Sol-Ark doesn't seem to give a damn about making it right.

[@Wrenchen-with-Darren]

Another point with growatt, the 10 and 12,000 watt all-in-one units have the transformer-s built in and I don't believe there is an issue with those units, at all.

[@firebird9232]

Sol ark pass electrical coding since its rapid shutdown compliant . ( NATION WIDE

[@fisherus]

@@firebird9232 The problem I have with the 59V 12K model I received is twofold. First, I am using a large battery bank compromised of 34 Toshiba LTO SCIB batteries. To get the best range from the batteries I need a Nominal of 60V and a charge rate of 61V, minimum. The other problem is down the road I want to piggyback another unit to this one. When you order a 12k Sol-Ark and 63V is what you based your purchase on and the manual that comes with the unit shows 63V, then you go to install it and find out it is 59V, it's upsetting. But, when they won't make it right then it just pisses you off to no avail.

[@eDoc2020]

@@firebird9232 2020 NEC does NOT require microinverters. The required shutdown can be achieved with much simpler modules.

[@firebird9232]

@@eDoc2020 PRETTY MUCH. yes one way is to use smaller modules under 30v ( yet 24v panels are 33v and up) and not put them into series but then your throwing money away on bigger hardware. so yes thats one way go 12v system. To bad that wont run a fully of grid house. how code is written mirco inverters are the way to go. "The rapid shutdown standards adopted in America and other countries stipulate that the voltage levels within solar conductors within >>>>1 foot

[@tirivaenim]

On the Pv side, do you have a Pv disconnect before the Inverter? If the Growatt was located indoors how bad is the fan noise in decibels, would it be tolerable you think in a small space setting such as a flat?

[@kaosfacey8804]

do you have a video about how to calculate how much solar panel you need to run certain amount of load

[@taulli1]

@DavidPoz Another great video, such a creative solution. I have seen numerous opinions regarding grounding the 5000 es from SS. Can you tell me, or add the link, should the: option 1. inverter, panels, auto transformer, batteries, and sub panel be grounded to grid ground in the residential panel? Or, option 2. should the residential ground stop at the sub panel which the inverter feeds, then all off grid inverter, panels, auto transformer, and battery have a dedicated and separate ground rod? I am grateful as always.

[@LITTLEEXPERIMENTCHANNEL1]

How do you cope in winter? Do you still work off-grid and have grid support to back up your battery bank.

[@zurubisana]

Hi, David. Why not consider use two or three of the SPF3000ES (120V L-N) to simplify the electrical system?