Hopefully tommorow will be our first day online with the new system, its going to operate independently along side the other system until I can afford the equipment to merge the 2. Im told the XW 24v systems aren't shipping yet anyway. Its been a bit of a head trip reading NEC codes and Inverter manuals to be certain the wiring configuration I came up with is correct. I ended up grounding the arrays as specified by Xantrex and Sunpower, but not on each module, I grounded the aluminum mounting rails instead since they bolt to the aluminum panel frames. I used UL Listed CU/AL certified outdoor lugs and Green #10 wire. The system is positive ground, which is strange to work with. In a pos-ground system your grounded and ungrounded conductors are swapped in color and location, so the positive wire is unfused and runs to what is normally the negative bus bar in the combiner box. Also the Negative (Ungrounded) conducor is black instead of white as normal and runs to the fuses which is also backwards from the typical setup. I have marked all my wires by color and tested polarities with a multimeter. This has been made more complicated by my choise to go with aluminum #4 before I even knew what type of system we would have. I had to buy UL Listed CU/AL certified splice blocks and heavy duty shrink wrap. I also used the anti-corrosive paste on the aluminum side of all connections. We know it works, durring testing my dad zapped himself with string 1 while it was cloudy, then we tested the line, 324 volts!!! HA HA.
We also got a lucky break at home depot, we are replacing our service entry at the same time and we bought 20 ft of 100 amp Copper Service entry cable for the price of 15ft of aluminum wire because they couldn't find the right price. Anyway, once I get this thing done I will try to find a way to upload some photos. Anyone have any Idea how to do that?