No brand/5500W inverter disaster porn

[noneyabussiness]

https://www.ebay.com.au/itm/ARC-220Amp-Stick-Welder-DC-Inverter-MMA-Welding-Machine-IGBT-Portable-10A-Plug-/272834881672?_trksid=p2349624.m46890.l49286

One of these with a couple of extra turns on the secondary side of transformer... again, OZTULES brilliant idea,  current controlled and everything... Ill try and find the thread later if you want

[rossw]

though i synchronize the two sources before a switch.

I have on occasion pushed stop button on controller which transfers all without regard to phase alignment.  Thats a fatal error

How do you guys do this? I know those with gensets just charge the battery but wondering if anyone else uses transfer relays

I'm not using PJ or similar (no insult intended) "low end, very basic" inverters.
My scenario is using commmercial "generator-interactive" inverters. When transitioning to generator mode, they initiate generator start based on various conditions (but typically SoC or DC volts). When generator input is detected, the inverter drifts its frequency to match the generator over a second or so, adjusts its output voltage to match the generator, and then drifts its phase to match the generator. When all three are "very close", a large contactor pulls in to join generator output and inverter output together with the load.

The inverter can then gently adjust its voltage/phase to gently transfer the output load to the generator, and indeed can go a little further to start pulling power from the generator to charge the batteries (using whatever headroom is left). Similarly, it can change it's output the other way to assist the generator allowing the pair to drive loads larger than either alone can.

When disconnecting, the contactor simply opens and 100% of the load is supplied from the inverter.

I've never had problems transferring to or from generator, the relay doesn't introduce a break (even briefly), and can be of a simpler "normally open" construction rather than change-over.

[lighthunter]

Ross, thats high tech. I didnt even know they made one like that. Very nice, probably higher end than i'd wanna go. I know, buy cheap and pay more later... can be very true. I think for some of us at least, grid power is so cheap its really hard to justify high quality equipment. Either way you do it, even if it costs more, its worth it to run RE equipment. My minor misfortunes havent cost much more than fets and drivers in most cases and provides plenty of hobby adventure along the way! Ha! probably why some of us are here anyway is the fun of making your own mistakes.

Ihad the parts for a simple charger so i put together yesterday. 12Amps at 49v 17A at 46.5V, this will do just fine and no more switching. I considered the option years ago, being an efficiency nut i hated to down convert and then upconvert when its already there, not a big deal though if you rarely use it. 

Noneya, i have two inverter welders, i just like em too much to repurpose. Great ideas though! thanks!

[Pete]

As we are totally off grid, I use a motor/alternator for charging my batteries on the very rare times we don't get enough sun.
Now that I have upgraded to 24 volt batteries I will get a 24 volt alternator to fit to the motor.
Years ago I used two alternators in parallel to weld with , they worked great but the noise was bad from the motor.
Firing up the inverter welder off the solar is so much more conducive to a peaceful time welding.
On another note.
Do any of you good gentlemen know which parts to delete on the powerjack inverter to get rid of the charger section.
I would like to tidy up the box and get rid of extraneous parts.
Pete

[rossw]

for some of us at least, grid power is so cheap its really hard to justify high quality equipment.

Some of us live 100% offgrid, with no practical option otherwise.
When you have a family to keep comfortable in todays high-tech, over-connected world, and your income is entirely from IT-related persuits, unreliable power simply isn't an option. Lose power, you don't have water pressure, you can't get in and out of the building, you can't even flush the loo, much less do the income-generating work that keeps food on the table.

In these circumstances, unreliable equipment isn't a mere inconvenience. You can't just "flick the switch and use the grid". It really is critical to our way of life, so the extra effort (and cost) is really "insurance".

[Pete]

Hi Ross, I agree with the practicality of having good gear. We live off grid, we did have grid power when we moved to our mountain but got rid of it and cut the poles down.( they make good gate posts). The grid here was unreliable and expensive.
I have one good inverter that is the spare ( an Australian made Latronics) and use a PowerJack as the main inverter.
I now have another Powerjack too that I bought as a dead inverter and repaired.
I have overcome my fear of surface mount components, but still prefer through hole ones.
I have set our place up with backups , got rid of the Pressure pump for water, and put tanks on the hill above the house so gravity supplies the water for a few weeks if the transfer pump dies.
Fortunately I have retired so there is no need to have electricity to earn money.
It is hard for me to come to grips with spending too much on power as I  have had solar now for 40 odd years and have gradually got bigger and bigger systems. I have never had the spare cash to spend on really expensive inverters. I can see the value in them reliability but fortunately having skills and spares helps.
Cheers
Pete

[lighthunter]

Some of us live 100% offgrid,

Yes, totally understand, Ive no doubt i would do the same. It why i used "some"  Im so spoiled my dad grew up without electricity till the 40s.

Speaking of expensive equipment, theyve now changed the code here in US to require PV mounted to buildings to rapid disconnect to 80v in 30 sec within 1 foot of the array. I use panasonic 400v relays for my strings. A solution might be move relays from inverter box to the arrays but they also have a sentence stating "all rapid disconnect equipments must be listed" i dont know if a listed relay in a listed weatherproof box is ok or not but i ordered a listed remote switch to be on the safe side. Youd think they would give you the option of running array wires in schedule 40 pipe. (i doubt fireman ax would go through it.) Its good stuff but a challenge to keep everyone happy.

[Pete]

Hi LH, what you describe sounds like what we had here. Here the regulators decided that every solar array had to have a disconnect switch on the roof. The problem was not may fire people want to climb onto the roof to turn the switch off. In the event of a solar panel fire climbing up to turn the switch off sounds pretty precarious.
One other problem is that many of the switches were not up to switching high voltage and current DC and they caught fire.
So one so called solution became a problem that is still being looked into.

Just wondering with your inverter board ( the aliexpress one) did you have to make any modifications to it to get it to be reliable.
I am in the process of building a ground mount for another 2kw of panels so after that is done I will look at the inverter board that I bought and see how it works.
Cheers
Pete

[lighthunter]

Hey Pete,I did do the current disable Nonya referred to a few posts back. The people who designed the board might have found a way around the issue i cant say for sure. It did work fine without the mod though. Seems like they had the low voltage shutdown already set somewhat close. I never touched it but i did set my low volt shutdown a bit higher so it would never use on board one. The reason i didnt care for theirs is it automatically retries in a few seconds. Doesnt seem to give up either. The last thing you want is to shut compressors off and on repeatedly.

[noneyabussiness]

https://www.anotherpower.com/board/index.php?topic=1116.15

At least do this one as OZ describes... remove/bypass the 393... check all caps as well...

[Pete]

Thankyou LH and Noneya, I will check my board and if it has the LM393 will do as suggested.
Still a way to go with my new panels.
Next step is to dig a 40 metre trench for the cables to get to the shed and regulators.
The only problem I have here is that whenever I dig a hole I have to remove rocks twice the size of the hole I want.
The joys of living in the mountains with lots of beautiful boulders around.
Thanks again
Pete

[rossw]

whenever I dig a hole I have to remove rocks twice the size of the hole I want.

You should write a book.
"DIY Trenching with detcord"

[Pete]

Good idea Ross. Many years ago when the world was a simpler place, I went and bought some gelignite. I was digging a well on my land in Southern NSW and hit rock at 3 metres down. So the shovel and crowbar were very slow then.
I had to go to the police station to get a permit to buy explosives, well a few simple questions later I had my permit.
Strangely enough one of the questions was " you are not going to do anything illegal with it are you?"
Now I did wonder who would answer yes to that and expect to get a permit.
Well blasting was hard too, as I had to make the holes for the gelignite with a hammer and a star drill, slow work.
These days explosives are not so easy to get legally .
So this trench will be built with the same idiot sticks ( shovel and bar) that the well was dug with.
Seems that 46 years has not taught me much about hole digging. Time passes, some methods stay the same.
Cheers
Pete

[rossw]

I was digging a well on my land in Southern NSW

Where in Southern NSW? grew up in Young in the Riverina, and have been in Albury on the NSW/Vic border for the last 45 years or so.

So the shovel and crowbar were very slow then.

Alas, they were then and still are now.
I have a hydraulic post-hole digger which was a great idea, but 2/3 of the strainer posts we needed still hit rock and needed the bar to get far enough, and far too many of the roughly 900 trees we planted had to have their holes dug in a second or third spot to avoid rocks.

So this trench will be built with the same idiot sticks ( shovel and bar) that the well was dug with.
Seems that 46 years has not taught me much about hole digging.

I recently bought a small (1.2 ton) excavator to go with my old bobcat.
Next trench I hope will be far less taxing on my tiring bones and muscles!

[Pete]

Hi Ross , I grew up in Sydney, but moved to St Georges Basin near Jervis Bay when I was 21. I bought 10 acres there then and lived there for 5 years. After a long stint on the NSW north coast I moved and now happily live in Tasmania. (where we have seasons).
I did have a powered post hole digger at my last property in Tas, but it would not work here. We live on a mountain that has boulders of Grandiorite everywhere and above us the rocks change to Dolerite. Powered post hole borers just end up in a wild ride in this country.
Would love an excavator but not enough work for one, and I don't like the damage they do in the hands of the inexperienced.
That would be me and most of the people I know who own their own machines.
So as I am still young (66) it is idiot sticks for me.
I have nothing but time anyway.
Cheers
pete