OK... I need a new brain, mine is done. Fried. Cooked. It even hurts now to drink beer.

Here's the deal... I bought 27 sunpower (215w) panels and a 5200 inverter... good deal.. craigslist... I took everything off the roof intact... meaning I unplugged the panels, inverter and other hardware but I did not disconnect wiring except from the panels and the dc and ac outlet. Left it wired, so I wouldn't have to remember how it all went back.

Hauled the whole thing home.. unloaded at the chicken house and reassembled... Laid it all out on the ground.. except a nice 8 inch pipe to hold the 130+ pound inverter and the other stuff. Just a test thing right??? I mean I'm not going to leave it that way ... just wanted to see it work.

Plugged in the panels, plugged in to the ac at the pole.. [added 200 ft of #8 insulated wires a nice red one, black one and a white one so I would have a 'dedicated' line] A green light on the inverter said 'OK'... and that sounded good to me. Red light said 'standby'... so I did that for awhile.. then got bored and threw the dc switch... I waited awhile and then it clicked, made a few more sounds... and the 'standby' light came back on... no error messages...

I have no manuals.. nothing... downloaded everything I could from sunpower, and found nothing except manuals that were really promotional brochures.. there was a thing about positive grd.

Found this great site and have have attempted to find out what a positive ground is... Please someone tell me what I'm doing wrong.... other than attempting this with no money and a tractor and horse education.

If I put an ohmmeter anywhere on the inverter box, pole, earth, panels, or whatever... it reads a completed circuit to my incoming power pole because my ground/common for the 240v a/c is within the inverter box.. as is the 'ground' from my panel array... So my panel array is really being grounded at the same place as my a/c pole.

How do I get a + grd which is not connected to the -grd ac? Am I supposed to insulate the entire dc side from the ac? If I do, ...how and what then do I use for my + grnd?

I've already talked to sunpower and a very nice gentleman told me they could not help as I had removed the unit myself and wanted to install it myself. Ok... I'm guilty, but it didn't seem to be rocket science... now I can't even drink beer.

Sorry if I sound simple, it comes honestly.
Wingshadow

did you actually see it working before you took it apart?

thanks for an answer.

Yes, It was spinning the meter backward when I took it off... It has even done so on mine... but only for between 10 seconds and 45 minutes... don't know what is making the difference as I am getting no error messages from the inverter. It just goes back to standby. I did not reinstall the mounting rails as I have the whole assembly laying on 2x4's on the ground for now. Can that make a difference?
Wing

Could be simply your ac is going out of spec with the temporary wiring, if it work when you took it down and now is going on and off line, the only difference is you AC connection. Adding 200ft of some random circuit could be a problem

OK, thank you, you may be onto something. I'm not sure of what a random circuit means. I installed all new #8 wire which was larger than spec for the distance. L1, L2, and grd. but now after much cleaning and changing of the ground connections...( I even installed a new copper 8 ft grd rod)... It gives me a fault code that says my ac under voltage fault. I put a meter on it and am getting about 250v... each side the same at about 125. Doesn't seem to fit what the code says as I'm well within the limits. Any ideas, and I will try them.
Wing

Question.... The way it is now, I have a 30 ft run from the panels to the inverter, and a 200 ft run from the inverter to the ac source. Would it be better to reverse that? I could move the inverter next to the source and run the dc through the #8 wire. I thought ac would have no problem with two hundred ft.
Wing

You should measure the AC and DC inputs to the inverter, one of the two is why its tripping offline. I wouldn't worry to much about it until you have the panels permanently mounted.

Since the DC side is the lower currently, it should have the longer wires

Ok, thanks. My input from the ac side is 254v ... My input from the dc side is somewhere between 390 and 410v, depending... so what you are saying is that the dc side is actually lower ( I guess that means the amps?) If I understand you right then I will switch the cable so the long run is on the dc side, and move my inverter next to the power pole. I arranged it the way I did because I was told ac travels distance better.

I originally didn't want to make my permanent mounts until I was sure the unit was working, because I was confused with how a positive and negative grd could share the same point, and I wanted to make sure the mounts were built to handle a positive grd. It still doesn't make sense to me,... As soon as I put a metal pole in the ground the ac and dc both share an earth grd.... but I'll leave it to you guys to understand the details.

It'll take me about a month to build the trackers as I make my own.. from scrap tractor stuff, and I have planting, milking etc. to do also.

I've made one holding ten panels that runs the dc motor to my well. (10x170 watt BP panels) It has worked fine for five years and I need to make three more of that physical size to handle this setup. (3x9) In the mean time I will try swapping the #8 wire to the dc side. Thank you for sticking with me.
Wing

The frame and equipment ground is just that ground, positive ground just refers to the PV sting +/- which is isolated.

So if you ground the string at the +, from ground, the pv voltage would be 0 to - 400v, referenced to ground. The pv voltages are all isolated, nothing except the invert input will see the pv input.

I talked to the people at Sunpower once and they told me they couldn't help because my warrantee was voided... but they did tell me to remove an incoming positive lead at the inverter from a pv string and test it in series to a grd. and that I should get a reading of zero if I had a proper grd. (I'm thinking now that he meant 'if the inverter was working properly')

I have three strings of nine panels and tested each dc lead individually in series with a good multimeter and got about the same reading on each... never a zero but it varied a lot (usually it read about ten to twelve volts) ... it doesn't seem to make a difference what I use for grd. I even get a reading of a volt or two with the ac side off, and just the breaker for the dc on.. (leakage?)

Thus came my confusion and eventually my inability to drink beer.