Hertz dropping on Conext 6848Pro

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Terrirws
Terrirws Registered Users Posts: 2 ✭
in Advanced Solar Electric Technical Forum #1
We are off grid and had a Schneider system installed with 3 of the "new" 6848 Pro inverters. Been complete nightmare. Our installer has been installing for 10 years and has hundreds of the earlier versions installed and said he's never seen anything like this.  When ags shuts generator off, all the arc faults (code here) trip and well pump won't run.  The install tech discovered that the hertz drops to 45 when the generator shuts off, but ONLY with the AGS. It doesn't do this when we use the manual switch. Schneider sent my installer experimental firmware (I say this because it hasn't been released yet apparently), and that solved the hertz problem. But now when batteries get to low voltage and gen comes on, the inverter won't charge the batteries and we loose power.  This crap has been going on for over a month and Schneider doesn't seem to have any answers. Any other off grid folks have this problem with this new version of the 6848XP?
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  • Dave Angelini
    Dave Angelini Solar Expert Posts: 6,758 ✭✭✭✭✭✭
    edited July 2020 #2
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    Did not ever notice that with the field test here that ended 15 months ago. Please list what firmware revision you were running, and the new one!  By default AC coupling is on. Is the frequency changing during charge? If so I would disable AC coupling.

    Where are you? NA ?   I would disable AGS and work on that later. You can start a genset right? 

    Please list historic faults, warnings, and events. Your problems probably stem from a setting mistake. I would list all settings that have been changed. If you can't, then a reset to factory may help.

    There are too many interactive settings that can cause issues. This alone is one of the reasons since XW came out in 2005, I have been for building an offgrid firmware version to get all of the grid settings out of XW. The same with Outback Radians. Just too many interactions that should not be in an offgrid power system.
    "we go where power lines don't" Sierra Nevada mountain area
       htps://offgridsolar1.com/
    E-mail offgridsolar@sti.net

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  • Terrirws
    Terrirws Registered Users Posts: 2 ✭
    #3
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    Had 03 first, in which Hertz were dropping after generator cut off.  Loaded 09 (not actually released yet, but given to my installer by Schneider to fix the problem.) That fixed the Hertz drop. (was not dropping during charge.)  The fault on the master was for low voltage, # 2 (slave) said "AC disconnect". For what it's worth, when 09 was loaded, the battery charge lights on  the front did not light up.
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  • RCinFLA
    RCinFLA Solar Expert Posts: 1,484 ✭✭✭✭
    edited August 2020 #4
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    You might trying tightening up the allowable freq range.

    Did you hear the relay open immediately?

    I have noticed when ACin is just open circuited (opening ACin breaker) when supplying little to no current into ACin the inverter sometimes wanders off without releasing ACin relay connection.  If you do a quick OFF, back ON, OFF of the input breaker the inverter disconnects and stays on freq.

    If you think about how the hybrid inverter connects to ACin, unless it detects a current change it doesn't really have a way to know the ACin has been disconnected.  The voltage to ACin will be supplied by inverter though ACin relay that stays closed when ACin breaker is opened with little ACin current.  Normally the ACin source will momentarily load down the input which is detected by inverter causing it to disconnect.

    Some newer generators, particularly inverter generators, tri-state float their output when generator is shut down.

    To make the control tougher for the inverter it has to sort out if the current change is due to a generator wobble in ACin freq or actually a disconnect.
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  • Dave Angelini
    Dave Angelini Solar Expert Posts: 6,758 ✭✭✭✭✭✭
    edited August 2020 #5
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    This is a known problem with multi unit XWP's  It will get fixed.

    For now, if you really need a genset in summer, I would wire just one XWP for a genset. Since you have 3, make the 3rd its own charger by disconnecting the stacking cables & xanbus, wire genset directly into its AC2.

    The other thing you can try is loading the opposite firmware for your region (the Hawaii electric). This has fixed a mult xwp system for genset. Maybe you have tried this?
    fw20191112_conext-xw-pro-120-240v-firmware-v1.03-rule-21-151-0317-01-03.zipDOWNLOAD 
    FW20191205_Conext-XW-Pro-120-240V-Firmware-v1.04-HECO-151-0317-01-04.zip

    The last thing if this is serious, is forget about AGS for now and manually start genset. Make sure AC coupling is not selected !!!

    Why do you need a 3 xw system offgrid BTW.  Good Luck?
    "we go where power lines don't" Sierra Nevada mountain area
       htps://offgridsolar1.com/
    E-mail offgridsolar@sti.net

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  • jbbonnette
    jbbonnette Registered Users Posts: 2 ✭
    edited June 2021 #6
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    My system just started doing the same.  I have two 6848's and it, at random, goes to 45.6 Hz.  Not sure if the AGS is the reason.  The timing would have about right though, the AGS was the last part of the system to be brought on line.  Now all kinds of problems.  If I reset the inverters by either going off of invert and then back on, or into standby and back on- it puts out 60 Hz again.  Eventually it dropps to 45.6.  I'm quite worried about the damage I've done to my well pump(s) and Air Conditioner.

    I just opened some trouble tickets with Schneider... awaiting a reply.  Everyone speaks of this a thing a year ago, was there a fix?

    Help please!!!
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  • Dave Angelini
    Dave Angelini Solar Expert Posts: 6,758 ✭✭✭✭✭✭
    edited June 2021 #7
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    You are seriously out of date on XWP firmware ! Current is XW Pro 6848 120V Firmware v1.11_BN0028.
    This was fixed about v1.5 I think. People were told  "then" not to run multi XWP until the firmware was revised. You should do that until you get this updated. Ouch on your loads!

    I never noticed this during field test because I only need a single XW offgrid. In most of the many homes I have been involved with,
     the owner has really outdated loads or has not tried to get an Offgrid mentality. The biggest offenders are old 2 ton air conditioning and electric dryers, ranges, and water heaters. Some having all four cycling or doing this at night along with a deep well pump! Arrrgggggg!

    I hope this is not you JB !
    "we go where power lines don't" Sierra Nevada mountain area
       htps://offgridsolar1.com/
    E-mail offgridsolar@sti.net

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  • jbbonnette
    jbbonnette Registered Users Posts: 2 ✭
    #8
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    Dave Angelini said:
    You are seriously out of date on XWP firmware ! Current is XW Pro 6848 120V Firmware v1.11_BN0028.
    This was fixed about v1.5 I think. People were told  "then" not to run multi XWP until the firmware was revised. You should do that until you get this updated. Ouch on your loads!

    I never noticed this during field test because I only need a single XW offgrid. In most of the many homes I have been involved with,
     the owner has really outdated loads or has not tried to get an Offgrid mentality. The biggest offenders are old 2 ton air conditioning and electric dryers, ranges, and water heaters. Some having all four cycling or doing this at night along with a deep well pump! Arrrgggggg!

    I hope this is not you JB !
    I paid the big bucks to Wholesale Solar (now Solar Unbound) for prewired power center.  My 2 Midnite Classic 150 already had to be replaced becasue WSS built it with a recalled line of 150's.  --this was after a month of use.

    I would have expected a brand new unit to have brand new firmware.  I've built to off-grid.  In fact, we closed on the house I had built yesterday and here I am today without power.  I don't have those loads you speak of.  I have an efficent ducted split unit as AC.  It works great.  Then I have a well pump and a boster pump.  My well pump fills a storage tank when the sun is bright, the booster fills a presure tank at much lower amperage.  This was all working great until 2 weeks ago.  It was about the time I installed the AGS as the Genset was the last part I put together.  I've reached out to WSS (Solar Unbound) as well.  I presume they will just say speak to Schneider.  You pay the "big bucks" for the tech suppport, but... It's realy just elemetry things.  I argued with them about my 150's, they where convinced they were fine.  Midnite said otherwise, they quickly informed me I was sold defective Charge Controllers.


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  • Dave Angelini
    Dave Angelini Solar Expert Posts: 6,758 ✭✭✭✭✭✭
    #9
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    You can't expect new firmware when the equipment is purchased from a retailer. They could have stock that is old. My Supplier drop ships from Schneider and so it is usually close to updated. How ever XWpro was a new product and early adopters are often the way things get tested these days. It is unfortuanate but  fact of life. It is upon the due dilligence of the owner to du the research.

    In my opinion, mixing different makes of equipment in a networked system like XWP is not good design!  Good Luck !
    "we go where power lines don't" Sierra Nevada mountain area
       htps://offgridsolar1.com/
    E-mail offgridsolar@sti.net

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