Delayed startup of Grid Tie Inverter

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Comments

  • jonr
    jonr Solar Expert Posts: 1,386 ✭✭✭✭
    Keep in mind that a grid-tie inverter needs to see a low impedance to the grid. Too high and and it won't start inverting.

    I am available for custom hardware/firmware development

  • sdcoffeeroaster
    sdcoffeeroaster Registered Users Posts: 5
    edited April 2017 #63
    BB. said:
    With the current matching the two strings so closely, either everything is OK, or the two strings have identical problems (unlikely, but possible).

    So is all working OK for you now? 10+ years on a central GT inverter is not bad--I would be saving money for a replacement (electronics last about 10+ years, and units over ~5 years old are difficult to get repaired / find replacement parts).

    -Bill
    Things seem to be OK now.  It was just short period of time I noticed the delayed startup and it was a very cold morning but extremely clear and sunny.  I still plan to look at the connectors and convert a couple to mc4 from mc3.  And yes I am planning for the day when the inverter does fail and then I'll get something in the 3 to 3.5 kW range and maybe two more panels.  I seem to have enough for my house and my new LEAF with this system.  I hit max, which is 1820 watts right around 10:45 or so and then the system is topped out until about 2:30 or so.  So I'm loosing about 4 hrs and maybe 2-400 watts/hr or so.  I have active cooling on the heat sink and the a fan inside the cabinet pulling in outside air from the bottom and exhausting at the top so the inverter stays pretty cool and it's inside the garage which also doesn't heat up too much.  I've had several 14.4 kW-hr days this last month and many in the high 13's.

  • sdcoffeeroaster
    sdcoffeeroaster Registered Users Posts: 5
    jonr said:
    Keep in mind that a grid-tie inverter needs to see a low impedance to the grid. Too high and and it won't start inverting.
    I was concerned about the AC out terminal block on the inverter circuit board.  I could not tighten one of the screws and was worried about too much resistance there.  It turns out the screw assembly was broken and I found the exact replacement at digikey.  I replaced it and now everything is snug so maybe that was an issue.  This late startup only seemed to occur for about 4-5 days during a very dry, cold and sunny period of unusual weather here and has not repeated.  I'm going to continue to check things out and plan to upgrade a couple of connectors to mc4 on the roof soon.  Other than that I'm not sure what else to look for and things seem to be behaving lately.