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Fronius IG 2000 issue

Ptom

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Oct 22, 2022
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I'll cut right to the chase: I stupidly (I was in a hurry is my only defense (?)) briefly (10 minutes) reversed polarity on the DC feed on my 15 year old IG 2000. This system was put together by me and has always worked flawlessly. When I discovered my screwup, I of course got the polarity correct, but cannot get it to go back online. NO error codes, just a flashing orange/yellow light from the display, with no response from any panel buttons. I have tried all combinations of everything off, DC off but AC on first, nothing works. I assume they are wrong polarity protected, idiot proof? All I have done is check the ground fault fuse, it's fine. I have missed 3 days of grid tie production, and it's driving me crazy!

This 1.9 KW array is at my crane yard (my day job) and produces enough power to almost zero out my annual power bills. Most of the year the only power used is to open the sectional garage door, the largest load is a 1 KW 120 VAC electric boiler for the radiant floor heat system. With the in slab thermostat set at 50, and the building being well insulated and 40' x 18' it's a good match. I am grandfathered in my utilities net metering system, I get every single watt back, no matter how long it's there, all for 5 buck a month basic connection fee.
 
I'll cut right to the chase: I stupidly (I was in a hurry is my only defense (?)) briefly (10 minutes) reversed polarity on the DC feed on my 15 year old IG 2000.
disconnect the PV, wait some time to drain any voltage that might be still there, measure with a volt meter on the inputs if there is any voltage.
Then do a diode test on the input, reverse your meter and measure diode again.
Are they the same?
DIfferent?

IG2000 _should_ be reverse polarity protected with a diode.
I have to assume there is a fuse internal on the circuit board that gets taken out in case of reverse polarity.
 
disconnect the PV, wait some time to drain any voltage that might be still there, measure with a volt meter on the inputs if there is any voltage.
Then do a diode test on the input, reverse your meter and measure diode again.
Are they the same?
DIfferent?

IG2000 _should_ be reverse polarity protected with a diode.
I have to assume there is a fuse internal on the circuit board that gets taken out in case of reverse polarity.
That's something along the lines of what I hoped to hear! I will investigate, maybe even pull it off the wall (it's 20 miles away) and bring it home, where I can do a deep dive on it and look for something resembling a fuse. Not my line of work exactly but a bad fuse I can deal with, circuit boards, not so much.
 
That's something along the lines of what I hoped to hear! I will investigate, maybe even pull it off the wall (it's 20 miles away) and bring it home, where I can do a deep dive on it and look for something resembling a fuse. Not my line of work exactly but a bad fuse I can deal with, circuit boards, not so much.
measure first before taking it off the wall
if there is no conductivity you should think about blown fuse
it could be short circuited, in which case need to have things repaired/exchanged
any thing in between is a guess.
Have your searched for fronius forum where others have experienced a reverse voltage?
 
GridTie inverters are not required to have reverse protection and I don't know of GT in of that age that did ( SMA , Trace, Xantrex , PVpower and Fronius) also that unit isn't NEC2011 which would prevent permitted use in most locations in the US. I tested just about everything available in that time frame under contract with Xantrex as part of their competitive testing prior to the release of the Xantrex GT series in 2005.

Good news is there are lots of options for replacements, I'd recommend a Solis 4G.
 
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No GridTie has requirements for reverse protection

Who made /where was that statement made ?
I looked back and couldn't find it!
and I know of GT in of that age that did ( SMA , Trace, Xantrex , PVpower and Fronius)
page 98 of the PDF (labeled page 96 in the pdf)
Screenshot from 2022-10-22 15-06-50.png

also that unit isn't NEC2011 and newer allowed to used in most locations in the US. I tested just about everything available in that time frame.
Why is that relevant?
He had it installed for years and worked fine.
Afaik it is not a new install
Good news is there are lots of options for replacements, I'd recommend a Solis 4G.
The only inverter I currently wouldn't recommend is a Solis.
 
I've taken a 5100 apart. I think it's the same as the 2000, just twice as many power modules internally and some different software/breakers/wiring. There are no fuses inside the 5100 with the exception of an AC fuse on the expansion card backplane. That I think needs to be unsoldered to be replaced, but it's not relevant to this conversation.

If you find someone into electronics that wants to take a poke at it, pass this on...

DC power goes through the breaker and then to a DC filter board buried behind the breakers. I've not seen this board myself, but online pictures of the Euro model 40 and 60 part show there are no fuses on it. Just coils, capacitors, MOVs, and a gas discharge tube. I would think the US part is the same. The power boards are the same as the euro counterparts, just different software for the voltage different. The filtered power then goes to the DC power board. This board has the brains on it, it generates 15v DC for the AC board, and the larger power/pulses the AC board turns into power. The wires feeding the DC power board from the filter board are not convenient to get to, but you could test for voltage there. If it's getting that far, it's likely the filter board is OK.

On the DC power board, the filtered DC power goes to a capacitor bank, then through a resistor network, to some transistors and finally a PWM chip. That chip generates the pulses that feed a mosfet which pulses a small transformer. The small transformer then generates power for the rest of the circuitry, and has a feedback circuit with the PWM to keep things regulated. That regulated power goes out and is further regulated to 5v, 3.3v, etc. This is my point though - next to the transformer are a couple of SMD components that may be diodes. They may be on the input side of the circuit as protection. Replace those and you may be back in business.

If it's not the diodes (or if they are not actually diodes), more troubleshooting would be needed. Due to the design using the switching power supply, most of the remaining circuitry is probably OK. The failure is likely in that power supply. While in that area, I would also replace the tiny MELF resistors near the label, and the bigger resistors above it. They are likely well cooked from years of heat - they were underrated IMO.

By the way, the DC power board has 4 small LEDS on it. If they are lit, the board is getting power from it's power supply. The 2 LEDS close together in the middle of the board are 5v and 3.3v indicators. The one closest to the transformer is for the 15v output to the AC board, and the last one is on the opposite side of the board near the COMM connection. It blinks when everything is working.

Good luck!
 
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It's on my shop's workbench at home now. I'll do some poking around tomorrow but will probably call an inverter repair shop in N Cal Monday and just ship it off. Or, buy new, I just realized it'd be a business deduction as it is for the crane building, that helps a bit.
 
I got through to Fronius tech today, and was told "I probably fried it." That was helpful! What it seemed to come down to, was pay shipping to send it off to a repair facility, wait an undetermined amount of time, and then pay the repair bill plus another shipping fee. Rather then do that, I ordered a Sunny Boy 3 KW, I would have gone with Fronius again but they are backordered for a month or so, and I have had good luck withmy Sunny Boy inverter for my wind turbine. Here's a pic of the inside, filthy! I did pressure wash it before re-mounting it and trying it again, just kidding, just gently hit it with some compressed air. One repair facility suggested unplugging the display, and plugging it back in a few times, that was the extent of their advice, and they didn't seem to interested in taking on it's repair. In short, it was time to move on I figured. I'll put it up on Ebay "WORKS PERFECT", kidding again, I'll clearly state it's issues and condition, maybe I can get enough to pay freight for the new one.
 

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