DIY 5kW system in San Diego Hyundai panels anyone?

[JFinch57]

Go to the Fronius website and find the configuration tool. I don't recall if it's web based or you have to download and install it. That will tell you your ideal string sizes. You might need 3 strings of 8 and have to buy 2 additional panels, 3 strings of 7, 3 strings of 9 etc. Doubt it will work with 2 strings of 11 but I'm mostly familiar with microinverters. I have a Fronius 38KW system with 3 10KW inverters, 55 panels/inverter on a commercial building that I paid to have installed. Ran the configuration tool to max it out on each inverter. One normally figures this out prior to purchasing panels.

[MARKSDCA]

Time for design. Lay out your panel wiring, perhaps 2 series strings of 10. Best voltage is
10 times Vmp, string current is Imp. You could run regular solar 10 gauge directly from
each string to the combiner function in the Fronius, 150 foot loop, 10 gauge is .001 ohms
per foot = 0.15 ohm. At 7A, Ohms law says you will lose about 1V out of about 300V for
the string, pretty good. Try cheaper 12 gauge and see if you like the tradeoff. If you use
a combiner at the panels, a single pair can carry the power back at double current.

My panels are up to 400' from their inverter, DC loses under 1%. Bruce Roe

Thanks for the detailed answer! I actually have a guy that's done the measurements and he's providing the plans for the permits. I have 22 270 watt panels so not sure how he will string them for the Fronius 6000. Very glad to hear that there is not a serious loss in the wiring/distance.

[bcroe]

Well I am a legend in my own mind.

So how much loss does one expect by having about 75 feet between the array and the inverter/meter?

Time for design. Lay out your panel wiring, perhaps 2 series strings of 10. Best voltage is
10 times Vmp, string current is Imp. You could run regular solar 10 gauge directly from
each string to the combiner function in the Fronius, 150 foot loop, 10 gauge is .001 ohms
per foot = 0.15 ohm. At 7A, Ohms law says you will lose about 1V out of about 300V for
the string, pretty good. Try cheaper 12 gauge and see if you like the tradeoff. If you use
a combiner at the panels, a single pair can carry the power back at double current.

My panels are up to 400' from their inverter, DC loses under 1%. Bruce Roe

[bcroe]

Not at the same time! But you knew that already.

So I sat there and waited for the sun to pop out from a morning cloud and I saw the amps shoot from 1-2 to 6 pretty fast...very cool stuff! I will test a bit later when the sun is stronger.

Waiting for good sun sometimes consumes weeks here in NW IL.

There is a Fronius 6000w inverter here too. I'm guessing you are going to run a couple
strings, each 10 panels 250W. When its operational, you ought to check that the 2 strings
are putting out very close to the same current under strong sun. If not, there could be
some cells that can't keep up, and are bypassed by the rest. good luck, Bruce Roe

[MARKSDCA]

I knew no such thing. I usually wear a bag over my head when I vacuum so as to remain incognito. Sunglasses are way too eccentric and Hollywood.

Well I am a legend in my own mind.

So how much loss does one expect by having about 75 feet between the array and the inverter/meter?

[J.P.M.]

Not at the same time! But you knew that already.

So I sat there and waited for the sun to pop out from a morning cloud and I saw the amps shoot from 1-2 to 6 pretty fast...very cool stuff! I will test a bit later when the sun is stronger.

I knew no such thing. I usually wear a bag over my head when I vacuum so as to remain incognito. Sunglasses are way too eccentric and Hollywood.

[MARKSDCA]

Wearing sunglasses while vacuuming seems a bit eccentric.

Not at the same time! But you knew that already.

So I sat there and waited for the sun to pop out from a morning cloud and I saw the amps shoot from 1-2 to 6 pretty fast...very cool stuff! I will test a bit later when the sun is stronger.

[J.P.M.]

Got the $20 multimeter from Home Depot and got 35V and 6.9A at 8:45 in the morning for a total of 240 watts from this 270 watt panel. It weas just leaned up against the BBQ in my backyard.

Disclaimer: I'm not an electrician or a solar expert but I did plug in a vacuum cleaner and wore sunglasses this past weekend so please understand the level of my credentials.

Wearing sunglasses while vacuuming seems a bit eccentric.

[MARKSDCA]

Got the $20 multimeter from Home Depot and got 35V and 6.9A at 8:45 in the morning for a total of 240 watts from this 270 watt panel. It weas just leaned up against the BBQ in my backyard.

Disclaimer: I'm not an electrician or a solar expert but I did plug in a vacuum cleaner and wore sunglasses this past weekend so please understand the level of my credentials.

[bcroe]

Now you have me paranoid. I am going to pick up a multimeter from Home Depot and make sure they generate some voltage when in the sun....I guess I could have done that when I picked them up but they were in an unpacked pallet.....hmmmm.

Its pretty hard to do a meaningful test in transit. And a voltmeter is the least meaning
test, if the first & easiest. I'd recommend getting a panel in good sun and check the
short circuit current. Hard to do that with a cheap meter, I'd find a 100 watt one ohm
resistor and connect it to the panel. Every volt across it indicates an amp of flow, and
yes it will get hot.

The real test is running at Vmp & near Imp. In string operation, I rejected several
panels that passed all the prelim tests, but just couldn't keep up with the rest of
the string. Bruce Roe

[MARKSDCA]

Oh, I missed your post that you picked them up, thought it was Craigslist from MA. Good luck, looks great!

Now you have me paranoid. I am going to pick up a multimeter from Home Depot and make sure they generate some voltage when in the sun....I guess I could have done that when I picked them up but they were in an unpacked pallet.....hmmmm.

[JFinch57]

Oh, I missed your post that you picked them up, thought it was Craigslist from MA. Good luck, looks great!

[MARKSDCA]

There are so many scams on Craigslist, I'd forget about that! I bought panels twice from Fred at HiTech Solar. He's on Ebay as Fred480V and here's one of his listings. He ships R&L and only takes Paypal, for which there is no additional fee. I recently bought 260W Isophoton mono panels that were not listed on Ebay, he sent me an invoice and I paid. The panels arrived 1 week later. See http://www.ebay.com/itm/25-255-MOTEC...item3cf69c81bf

I picked them up already......they were in an unopened pallet and had 2014 manufacture date on them...great looking panels......seems legit to me. http://losangeles.craigslist.org/wst...951536238.html

[JFinch57]

I got the 260W version of this panel but they're not installed yet. He probably has more. http://www.ebay.com/itm/20-245w-Isof...item3f4a5caa18

[JFinch57]

Found them on Craigslist in Topanga / Agoura

There are so many scams on Craigslist, I'd forget about that! I bought panels twice from Fred at HiTech Solar. He's on Ebay as Fred480V and here's one of his listings. He ships R&L and only takes Paypal, for which there is no additional fee. I recently bought 260W Isophoton mono panels that were not listed on Ebay, he sent me an invoice and I paid. The panels arrived 1 week later. See http://www.ebay.com/itm/25-255-MOTEC...item3cf69c81bf