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Re: 5000w hybrid inverter for grid assisted solar charging

Posted: Mon May 20, 2019 1:12 pm
by ripple4
i used thick foil tape with acrylic adhesive to seal the gap i left between all the panels. i left about a 3/8" gap panel-panel, i only needed 1/32" of an inch to cover me from a CTE point of view. That said the glass does not seem to be sealed very well to the aluminum frame, and some drips come through. to stay grounded keep in mind The walls are 8' of screen so a robust wind will blow rain into the area a good ways, water always wins.

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Re: 5000w hybrid inverter for grid assisted solar charging

Posted: Mon Jun 10, 2019 8:12 am
by ripple4
Here is a idea how the PV combiner box finished up. I have two, two-pole DC breakers that switch PV+ and PV- to completely isolate PV from the circuit. then i have two parallel MOV packages for each PV+. On the panel layout, I ended up going with a 8-series arrangement instead of 6-series like i had planned before, which put the OCV at 362VDC. which is really close to my 240vAC MOV clamping voltage of 390VDC, so i stacked two MOVs in series to get a clamp voltage of 780vDC, which is fine for shunting lightning surges to ground and well below the 2000v rating of the PV wire i used. i'll have another ~580vDC MOV at the inverter inputs too. I ended up useing a MOV intended for a 120vAC and 240vAC in series to get 585vdc clamping, measured with a fluke 1000v insulation tester. the ac and dc rating of MOVs are different because the AC rating accounts for peak to peak voltage plus about 14%, where DC the RMS and peak are the same. typing that all out might make it seem like I may be a little overboard on surge protection, and that might be true.

https://ibb.co/dtpS8FH

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https://ibb.co/zXX929R

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there is also a labeled PV DC disconnect at arm level and outside facing for first responders to use, I have the breakers in the roof-mounter combiner box acting more like a switch for service in that box. in the event of a really good surge the MOVs will explode and need to be replaced.

https://ibb.co/Pcg8QBk

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Re: 5000w hybrid inverter for grid assisted solar charging

Posted: Tue Jun 11, 2019 8:42 am
by ripple4
The AC and non-battery DC wiring is completed, all 10awg stranded thhn building wire, no lamp cord. one idea that worked well was how i did the cable tray on the bottom. they don't sell real cable trays at my local hardware store so i made one out of 6x 3/4" knock out handy-boxes, this is needed to keep the fan inlets free for airflow and the little conduit pieces are so close to the inverter and Xfer switch its little-finger safe.

The battery is still a work in progress, 286x of the the LiFePo4 battery cells came in, still waiting on a few more, the 120a BMS, and cell level fuses too. i was thinking that i would encase the battery in 4x large ammo cans, that way 3 of the ammo cans are a useful 12v 4s size and the 4th one which is 3s can hold the BMS. the plan is 32p 15s overall, 208AH capacity and 120amp max discharge.

Re: 5000w hybrid inverter for grid assisted solar charging

Posted: Mon Jun 17, 2019 7:22 pm
by ripple4
Well, for those waiting for their 'I thought it was too good to be true' moment this is it. the 3-in-1 solar converter did not work out. I connected the PV, and the box made some unsavory noises, and then turned into a short circuit. no idea what happened, other than error code 9 on the LCD, but the array had 311vdc and when I close the breaker it goes to 2.5VDC, just like a short. its not to ground, PV+ and PV- are shorted.

So I found a different way to do it, significantly more expensive though. instead of a 3-in-1 unit I'll try to get higher feature-content individual parts. most importantly, I have a epever 200 VDC, 100a MPPT 48v charger coming, which has a generator start and inverter load function. Since the solar input voltage is much less I'll need to break the solar array into 4S-4P panel arrangement instead of 8s2p, I'll just need to add a few more feet of PV wire and terminate some extra MC4s, no big deal.

the battery is taking shape, my 32700 cell endcaps are on thingaverse. https://www.thingiverse.com/thing:3691963

Re: 5000w hybrid inverter for grid assisted solar charging

Posted: Tue Jun 18, 2019 9:25 am
by Marktm
Bad 3 in 1 box or some type of hookup/misuse issue? Following closely for a success!

Re: 5000w hybrid inverter for grid assisted solar charging

Posted: Tue Jun 25, 2019 7:08 pm
by ripple4
if i connected the 3-in-1 box wrong, then i still don't know what that wrong thing would have been. some MPPT controllers have specific order for connecting the battery first and then solar etc, and some are positive common. but as far as i can tell i did it right. once it opened it up i found the BUS+ and BUS- connectors are shorted out, so the FETs of the inverter this are probably bad. the seller claims they will send a new board, i'm not holding my breath.

Re: 5000w hybrid inverter for grid assisted solar charging

Posted: Fri Jul 05, 2019 7:25 pm
by ripple4
Update on the battery for the solar Leaf charging project. I could not find ammo-cans that fit the bill to hold the cells. some where close, like the so-called FAT 50, but with 2 cubic feet of battery, it was a problem. so I ended up buying an aluminum trailer storage box from amazon, it was too close a fit and needed a 2" extension because the handles stick in not out, but its moving along at least. I can 3D print 2-3 end caps per day.

outdated info removed for clarity. see page 5 for finished battery case.

this is much larger project than I had first anticipated, if not for intestinal and financial fortitude I would have long since quit this idea. Afterall, it just does not cost that much to charge with grid power! these are the pros, they make power for a living! The whole idea of the cheap 3-in-1 solar gizmo got me started, but with the crap quality, I found out how much it really costs to do this, the payback is not going to be as few years as I first thought, but I'll still make back 2x my money in the life of the system.

Re: 5000w hybrid inverter for grid assisted solar charging

Posted: Sat Jul 06, 2019 3:54 pm
by Marktm
If it was easy, everyone would do it! Don't think "everyone" could add 2" to an aluminum box.

Re: 5000w hybrid inverter for grid assisted solar charging

Posted: Sun Jul 07, 2019 1:42 am
by Oilpan4
There's also 40mm grenade cans. I use those for welding rods because they are a little deeper and wider than a 50 cal ammo can but I can fit 18 inch long welding rods in them.
Then there are 20mm ammo cans. They are much bigger.
My next "12v" LiFePO4 battery I build will probably go in a 40mm grenade can.

It pays to buy the good stuff.
The only alternative energy stuff you can kind of go cheap on is stuff that's not electric and doesn't have moving parts. Which narrows it way down to panel racking. But if you live some where with sea spray or is always wet, you probably have to buy the high end stuff.

Re: 5000w hybrid inverter for grid assisted solar charging

Posted: Sun Jul 07, 2019 5:27 am
by BrockWI
not exactly the same thing, but along those lines check out that Jehugarcia built in his portable power pack. He has also built some home made power walls.

https://www.youtube.com/watch?v=bn0KtdrpoEM