Everything Solar Forum

communities_1.jpg

 View Only

  • 1.  Inverter Was Dropping - High Grid Voltage To Blame

    ASES Life Member
    Posted 11-15-2022 12:54 PM
    Hello Solar Friends:

    I wrote last Spring about an issue we were having with our grid-tied inverter (Trace/Xantrex 4024 w/battery backup), which would disconnect from the grid for a few hours mid-day on weekdays but not on weekends, nor when it was cloudy.  Two solar installers reviewed our installation and concluded the problem was not with our system, and to contact our local utility, Pacific Gas & Electric.  

    Last Summer I had them out and carefully scheduled it so the technician would arrive mid-day; he quickly noted our incoming grid voltage was 256, which was out of spec for the nominal 240 (they're allowed to be within 5% of 240; between 228 to 252).  He made a call and identified a boosting device on our block that boosted the voltage on weekdays but not on weekends (one mystery solved), and turned the thing off.  

    However, peak voltage on a sunny days was still hitting 253, and the inverter still dropping, so I had a second PG&E technician out; he arrived in the evening, when voltage had fallen to within spec, so he could do nothing.  Side note: there are many PV systems on our block, which is causing the mid-day voltage to climb.  Called again and a third technician lowered it further, to a peak of 248.  The inverter is now staying connected, and the charge controller recording 2 to 3 times the daily kWh we were collecting in July when it was dropping consistently.  

    Mystery solved, and worth sharing in case anyone is having similar issues ... check your grid voltage!

    David Arkin - Albany, California
     
    *  *  *  *  *
    Arkin Tilt Architects
    Ecological Planning & Design

    Please Support my 2022 Climate Ride Green Fondo, May 13-15, 
    with a fundraising goal of $2,500 to support CASBA. Thank you!

    David Arkin, AIA, Architect
    LEED Accredited Professional
    CA #C22459/NV #5030/OR #6738

    1101 8th St. #180, Berkeley, CA  94710
    510/528-9830 ext. 202
    www.arkintilt.com

    "There is no way to peace. Peace is the way."
    - A. J. Muste



  • 2.  RE: Inverter Was Dropping - High Grid Voltage To Blame

    ASES Life Member
    Posted 11-16-2022 11:32 AM
      |   view attached
    Right after installation my Outback Skybox inverter was doing the same thing, reacting to high grid voltage by disconnecting and/or stopping sell to grid.   Here in Ohio utilities are allowed +/-10% variation from 240V nominal and mine wasn't amenable to adjusting the output, which regularly exceeded 264V.  So I installed a 10kva transformer in the grid-tie connection to the Skybox and used a 5% voltage reduction tap on its secondary to reduce what Skybox is seeing.  Problem solved and no issues with low voltage, either.

    ------------------------------
    Mike Curran
    Retired from (dare I say it?) Fossil Plant Mgt.
    ------------------------------

    Original Message


  • 3.  RE: Inverter Was Dropping - High Grid Voltage To Blame

    Silver
    Contributor
    Posted 11-16-2022 10:47 PM
    I am surprised you didn't just raise the L1-L2 top to 260vac (130VAC each leg to ground). That is high but not unheard of.
    In the old days you could even go to the electric supply houses and by 130vac light bulbs for those people who lived in higher grid voltage spots. Their light bulbs would therefore last longer (Pre LED).

    ------------------------------
    william fitch
    Owner
    www.WeAreSolar.com
    ------------------------------

    Original Message