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Forum Index : Electronics : Are SMA SunnyBoy suitable candidates for harvesting torodials from?
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Alston Regular Member Joined: 04/04/2021 Location: AustraliaPosts: 62
Posted: 06:11am 11 Apr 2021
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I am trying to find suitable grid tie inverts to harvest transformers from for an invert project. The Aero-Sharps seem to be difficult to find (at least in WA) but there seems to be a number of 1.5kw - 2kw SunnyBoy inverters on the secondhand market (the LF type of course). I have found 1 1.5kw Aero-Sharp locally which I might try and grab but it seems to be the 3kw models everyone has used. Has anyone had any experience with the SMA inverters?
Murphy's friend Guru Joined: 04/10/2019 Location: AustraliaPosts: 582
Posted: 07:55am 11 Apr 2021
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I have used a toridial transformer salvaged from a sunny boy inverter (it had a yellowish case)and I think its being used (after re winding) in my warpinverter now.
You could place two cores together and wind around both to get twice the power rating. For home winding its always better to have a core with a big diameter hole. Whereabouts in WA are you? If in Perth that is where I am located, I have some left over inverter stuff you might be interested in if you are starting out building them.
rogerdw Guru Joined: 22/10/2019 Location: AustraliaPosts: 793
Posted: 12:46pm 11 Apr 2021
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Hi Alston, and welcome to the forum.
I can give you some info.
I've had the same question as to why SMA is never mentioned for toroids ... and the only reason I can come up with is that (at least some of) the SMA toroids are encapsulated ...
... which means you can't unwind them and reuse the wire like you can the Aerosharps ... and if you do want to use the bare toroid, you need to destroy the rest to get it apart.
Here's a pix of a 2kW SMA and a 2kW Aerosharp toroid
A closeup of the SMA 2kW ratings ... 153V Prim 230V Sec
Aerosharp 2kW Tx ratings ... 230V Prim 250V Sec
And last ... specs of a 1.5kW Aerosharp toroid ... 93V Prim 230V Sec
Cheers, Roger
Alston Regular Member Joined: 04/04/2021 Location: AustraliaPosts: 62
Posted: 01:38pm 12 Apr 2021
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Thank you both for the reply and thank you Roger for that excellent info. That's a shame about the potted transformers in the SMAs, although I guess if the price was right it still might work out OK to get the cores.
Murphy's friend Guru Joined: 04/10/2019 Location: AustraliaPosts: 582
Posted: 02:08pm 12 Apr 2021
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Regarding those 'potted' cores, look at them carefully, they might come apart. When I saw Rogers picture I remembered I still have that green plastic housing here from which I extracted the toroid. Can't remember exactly how, too long ago, but I got it out somehow without destroying the green housing.
When I was buying Aeroshars cores the going price for the whole 3KW box was $50.- I think they got less for scrap as there is so much work involved to separate the recyclable materials. So don't pay too much and try solar installers for your dud inverter source.
nickskethisniks Guru Joined: 17/10/2017 Location: BelgiumPosts: 409
Posted: 08:22pm 12 Apr 2021
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I got the same problem with the Diehl platina inverters, in my journey to find cores for my ultimate inverter build it was clear, bare cores were very pricey. No aerosharps in Europe to salvage, and everything broken gets sold as there is a ton of gold in it.... Even now old inverters are still sold for stupid prices.
So eventually I bought a whole pallet (I think about 14? Ranging from 2,2-4,6Kva) of broken inverters for about 50/piece including transport from Germany. I must say transport cost was almost the same as the inverters. I knew they had toroids in them but all potted. But it's doable to dissameble them, but the outer winding is for scrap. All you need is a chisel and a hammer, and about an hour of your time. It's a long term project, I just repaired 3 inverters for my dad and dissmantled 1 toroid. Edited 2021-04-13 06:25 by nickskethisniks
rogerdw Guru Joined: 22/10/2019 Location: AustraliaPosts: 793
Posted: 11:32pm 12 Apr 2021
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I see you're in WA and I don't know if they sold Aerosharp over there or not.
I'm in regional SA and I started by looking online for inverter repair places in Adelaide. Found a few and the first one said yes we have some here. I made the trip and came back with four ... $25 each.
Some time later I picked up some more from them, same price ... and when I couldn't get my final 3kW one, I tried one of the other places.
They wanted $50 each which I was happy to pay.
I didn't really consider pulling the SMA one apart seeing the Aerosharp ones are so easy to dismantle ... but having said that, if they are your only option, it's definitely worth a try.
Good to hear, thanks Nick. Nothing beats actual experience.
I repair circuit boards for a living and one particular type comes in that is potted. No one else will tackle them but now that I've worked out how to get into them, I actually enjoy the challenge of fixing them.Cheers, Roger
MasterCATZ Regular Member Joined: 25/03/2011 Location: AustraliaPosts: 52
Posted: 08:57pm 13 May 2021
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really sad as someone nearby had 40x SMA 5kw in their dead pile stash , but all encapsulated
Davo99 Guru Joined: 03/06/2019 Location: AustraliaPosts: 1577
Posted: 09:20pm 13 May 2021
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I thought if you soaked them in Acetone the encapsulation would melt off?
rogerdw Guru Joined: 22/10/2019 Location: AustraliaPosts: 793
Posted: 12:39am 15 May 2021
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Wow, that's a decent amount of toroids. Are you sure they are all older ones with toroids?
I discovered a while ago that if the model number ends in TL ... it means "transformerless"
If they do have transformers, it would be interesting to see the specs on them ... as they could still be useful. eg the 2kW one I showed above has a primary of 153v and secondary of 230v at 9.6 amps
From what Murphy's friend mentioned above, he obviously found a way to get the cover off ... and Nick must have just chiselled off the top winding and after that could unwind the rest or maybe even use what's there.
What state are you in ... location of these 40 SMA's?
Even if not used for inverters, toroids demand a decent price on ebay alone, though will depend on voltages etc.Cheers, Roger
brucedownunder2 Guru Joined: 14/09/2005 Location: AustraliaPosts: 1548
Posted: 02:16am 15 May 2021
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Alston..
Have you tried to contact "Domwild" ,he's over near you ,and sells a lot of backshed type gear. Maybe he has the Torodials you will find suitable.
Other than that , I see them available from most Solar installers or repair shops or tradies, I picked up 3 for $25. they just happy to get rid of them ...
Just have to knock on their doors until you find a small contractor that wants beer money.
BruceBushboy
MasterCATZ Regular Member Joined: 25/03/2011 Location: AustraliaPosts: 52
Posted: 09:35am 07 Dec 2021
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QLD on Sunshine Coast
and I think it will be impossible to find them in my Facebook messages now
Alston Regular Member Joined: 04/04/2021 Location: AustraliaPosts: 62
Posted: 09:32am 12 Dec 2021
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It has taken me a while but I have slowly been gathering parts for a Warpspeed inverter built. I managed to get an Aerosharp for the first transformer and then a smaller SMA inverter for the second. I knew I would need to destroy the the outer winding if I wanted to use the SMA toroid but the potting compound is proving very difficult to remove. I have cut away most of the green housing and have tried acetone but it doesn't do anything to the potting compound. Murphy's Friend is it possible that you might have tried to boil it hot water as I have seen people use that technique for potting compound? Anyone have any tips?
wiseguy Guru Joined: 21/06/2018 Location: AustraliaPosts: 995
Posted: 02:33pm 12 Dec 2021
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The only thing I found that softened it was brake fluid but I didnt have enough to give it a decent bath to soak in. Being impatient I then decided to do it by hand. The first step was to remove the toroids central aluminium mounting mandrel.
Simple, get my large club hammer and a ~ 20mm dia steel bar length and bash it as hard as you can & I mean real hard, then repeat over and over then give up ! It didnt move 1mm
Then use a drill to drill multiple 6mm dia holes all around the mandrel on both sides & elongate the holes to all meld together and then eventually remove the mandrel after ~ 1.5 hours. Then use a chisel pliers and a shipload of effort to lop off all the square edges - dont worry about marking the wire - you will never be able to re use it unless someone finds something magical that dissolves the potting crap.
My hands were raw at the end of many many hours of toil and I had hundreds of 2 or 3 turn segments still with the encapsulation stuck all over them lying in a big pile on the floor. I have another 3kW one asking for the same treatment but I haven't worked up the energy/enthusiasm to attack it yet. I'm thinking an angle grinder is worth a shot but that will also be messy and great care needed not to damage the 240V inner winding underneath.
Nicks reckons its about an hours work but either he got a different type of potted unit to mine or I'm really beginning to show my age ! If you find an easy or easier method please post it ! Good luck. Edited 2021-12-13 00:37 by wiseguyIf at first you dont succeed, I suggest you avoid sky diving.... Cheers Mike
Alston Regular Member Joined: 04/04/2021 Location: AustraliaPosts: 62
Posted: 12:50pm 13 Dec 2021
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Thanks Wiseguy, I used your technique to get the centre out. Your are right that was a huge amount of work to get that out. I have stopped for the night and will need to tackle the removal of the rest of the compound and top layer of winding. Wondering if this is worth the effort!
Murphy's friend Guru Joined: 04/10/2019 Location: AustraliaPosts: 582
Posted: 07:54am 14 Dec 2021
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Hmmm, the toroid I 'freed' from encapsulation must have had different stuff in it. It was some years ago but I did not remember it being as hard as wiseguy describes.
How about sandblasting it off? Powder coating places should have a big enough blasting cabinet. Once its cleaned to the outer winding surface it should be possible to start unwinding that.
Haxby Guru Joined: 07/07/2008 Location: AustraliaPosts: 418
Posted: 10:58pm 14 Dec 2021
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I have a contact in Melbourne who deals in second hand solar equipment. He is sitting on 6 aerosharp inverters of various ratings. He usually charges $50. If anyone wants a lead, please PM me. Obviously shipping to another state would be prohibitive as they are heavy.
Alston Regular Member Joined: 04/04/2021 Location: AustraliaPosts: 62
Posted: 01:16pm 15 Dec 2021
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Edited 2021-12-15 23:18 by Alston
wiseguy Guru Joined: 21/06/2018 Location: AustraliaPosts: 995
Posted: 02:11pm 15 Dec 2021
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That looks very familiar - there is still a lot to do though. I reckon an angle grinder with one of those wood carving/shaving discs would remove a lot of that potting crap (along with a bit of varnish.....) in good time. That would also help simplify the energy needed during unwinding. You just need to be careful around near the inner 240V winding wires and where they exit.
I have a mandrel that looks just like that too I'm curious how long did it take you to remove - I'm hoping you don't say 5 minutes..... mind you I was learning as I progressed.If at first you dont succeed, I suggest you avoid sky diving.... Cheers Mike
nickskethisniks Guru Joined: 17/10/2017 Location: BelgiumPosts: 409
Posted: 07:24am 19 Dec 2021
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Let me nuance my 1h statement, this was done with a 1400VA transformer. Apparently there is a remarkable difference between a 1400VA transformer and the 2700VA transformer I did today, both potted with grey stuff. The difference between the 2 is that the bigger transformer has a much thicker layer of potting on it then the smaller one, it also has bigger gaps between the wires. This makes it a lot more difficult to go thru that stuff. I think I spent about 1h30 this time, but went for the core only. I tried some different things this time, like using a cordless drill hammer but I had the feeling doing it manually my strokes had more impact.
I lost time chipping of stuff on both side, you really only need to do 1 side first if you are not saving the windings. Then smashing as hard as you can on the middle part, it should come loose. Both windings were damaged this time, this because of the electrical hammer, and so I didn't try to safe the 230V winding this time. The wires of mine were very thick, 3.4mm for the low voltage winding and 2.75mm for 230V. The 230V winding was on the outside of the core so I couldn't save it.
You could ask yourself if it is worth the effort, better to source a non-potted transformer for sure. But over here I can't buy those cores, and should import from UK.
I forgot to take pictures, but this was the battlefield:
Notice. New forum software under development. It's going to miss a few functions and look a bit ugly for a while, but I'm working on it full time now as the old forum was too unstable. Couple days, all good. If you notice any issues, please contact me.
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I'm curious how long did it take you to remove - I'm hoping you don't say 5 minutes..... mind you I was learning as I progressed.
