DIY 5kW system in San Diego Hyundai panels anyone?

[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]

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?

[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

[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

[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.

[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.

[bcroe]

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.

I don't know how they define "ideal string size", but I've been running 12 250W panels in series
for 40,000 hours, no issues and comfortably within Fronius specs. Series uses the least wire and
gives the least transmission loss, and makes makes practical using the Fronius built in combiner
function.

However, if an outside DC disconnect is needed and the Fronius is mounted inside, an outside
combiner will be needed anyway. Or if some panels will be subjected to shade, those should
be grouped into their own string; that could be a good reason for shorter strings. Bruce Roe

[MARKSDCA]

I plan to have 2 strings of 11 panels each. No shade problems on my roof. Inverter has built-in DC diconnect and will be mounted outside. Panels are 270 watts and specs here:

http://www.solarworld-usa.com/~/media/www/files/datasheets/sunmodule-plus/sunmodule-solar-panel-270-mono-ds.pdf

Fronius 6.0-1 specs here:

https://www.fronius.com/cps/rde/xchg/SID-8D089B31-3339B3AF/fronius_usa/hs.xsl/2714_10606.htm#.VSQ-Tyx0wSk

[JFinch57]

The configurator tool says that 2 strings of 12 may be undersized. Fronius1.JPG

[MARKSDCA]

The configurator tool says that 2 strings of 12 may be undersized. [ATTACH=CONFIG]6236[/ATTACH]

You know the configurator doesn't have the correct specs for my Solarworld SW 270 Mono blacks....my specs are in the attached pic.

Pmax 270
Voc 39.2
Vmpp 30.9
Isc 9.44
Impp 8.81

SOLAR270XXXAA.jpg

[JFinch57]

Good catch, not sure why there is a discrepancy unless Solarworld updated their module. I would send an email to Fronius, or call them, and ask to have the tool updated. If you run it as a 275W it's a lot closer to the specs and says that you're good with 2 strings of 11.

[MARKSDCA]

Good catch, not sure why there is a discrepancy unless Solarworld updated their module. I would send an email to Fronius, or call them, and ask to have the tool updated. If you run it as a 275W it's a lot closer to the specs and says that you're good with 2 strings of 11.

Yes that's what I figured!

Like the San Diego sunshine my panels outperform expectations.

[bcroe]

I believe the configurator tool is trying to say (correctly or not), a 6KW inverter is
too big for 22 panels. Is not tied to how they are arranged. Since the inverter
was a bargain, guess it will stay, at a small loss of efficiency. Bruce Roe

[emartin00]

I plan to have 2 strings of 11 panels each. No shade problems on my roof. Inverter has built-in DC diconnect and will be mounted outside. Panels are 270 watts and specs here:

http://www.solarworld-usa.com/~/media/www/files/datasheets/sunmodule-plus/sunmodule-solar-panel-270-mono-ds.pdf

Fronius 6.0-1 specs here:

https://www.fronius.com/cps/rde/xchg...m#.VSQ-Tyx0wSk

Keep in mind that the 2014 requires a DC shut off within 10 feet of the array, or 5 feet inside the building. Unless your inverter is right near the panels, you may need a seperate DC disconnect.

[bcroe]

Keep in mind that the 2014 requires a DC shut off within 10 feet of the array, or 5 feet inside the building. Unless your inverter is right near the panels, you may need a seperate DC disconnect.

Does that include ground mounts? Bruce Roe