KACO Powardor problems with limited DC input

  • Hello


    I,m sorry that you write in English.


    I have following problems our Kaco Powardor 33.0 TL3 and more precisely with DC input.The inverter limited DC voltage to 230V some time without any signal on display.Do this without any logic.When I disconnect string from the input and measure the voltage normally gives about 900 volts at idle. Do not do it constantly but reflects to the graph of production and there are days in which the tragic situation and all other days is almost perfect. The corresponding input has two strings on panel 22 x 180Wp.


    Can anyone help me with this problem.


    Or at least point me where could be the problem.


    Please

  • Hello epihov and welcome to our PV-Board ;)


    I´ll try to give u some hints, dont hesistate to ask if something ist not despricted clearly enough..


    Do you own an DC-Current clamp? This is a gauge to measure the dc current in the string cables and the easiest way to compare between several strings during operation of your inverter. If not, you should get an item, maybe from any auction platform or online stores.


    -Did u check the seperal String fuses? (if available)
    -Did u check the overvoltage limiter? (if available)
    -Which firmware version do u have at the moment? -> Use an USB Stick to get the newest version. FW and manual available at Kaco website...
    -You wrote, that your open circuit voltage is about 900V... thats really much, and its possible that you blow up ur MPP entrance during cold weather conditions. -> How long does ur problem already exist?
    -Possible too, are lightning strikes on ur array, so broken or short circuited bypass diodes might be appered -> no Power on this strings - but this failure must be constant...
    -Did u already cross-connect ur strings to another MPP?
    -Do u have moving shadows on the array?
    230V ist the bottom line of voltage, the MPP can work. Means the inverter doesnt find the Max Point of Power.
    -What amount of current does the display show at menu "DC" during normal operation? Is the weight about 3:3 on the other mpp´s? (u have 8 strings on this inverter?!?) -> 3:3:2? -> DC voltage at this point?
    -Do u have isolation problems during bad weather?
    -What DC start up voltage is programmed?
    -where does this power plant "live"? ;)

    Ok, a lot of questions, try to get some photos of ur opened inverter to chechup which hardwareversion u own, and find maybe visible failures. U can also give us photos of ur menu entries dc, ac and firmware -> menu information


    best regards, Andreas

    Andreas Witt
    Industrieservice und Montage
    Am Dorfplatz 7, 24214 Neudorf
    Tel.: +49 151 44 555 285
    info@pvservice.net
    USt-ID: DE 292086601, Handwerkskammer zu Flensburg



    Dienstleistungen rund um Photovoltaik: Wartung, Repowering, Datenlogging, Direktvermarktung & Redispatch 2.0, Anlagenplanung und -Neubau, Huawei Wechselrichter, Zubehör und PV- Komponenten

  • Hello
    Thank you for your interest in my problem.
    Before I answer I will try to give some more information on the findings and conclusions of my electrical measurements. And will get some data from the inverter.
    First Look at the information behind by the inverter see that the problem makes it somewhere in April 2014. The problem is that now I find it.
    The relevant DC inputs have tied monocrystalline panels as follows:
    DC -1 three parallel strings of 22 modules Genius SDM 180.
    DC-2 three parallel strings with 22 modules Genius SDM 180.
    Dc-3 two parallel strings with 17 modules Sun Tech 195.
    In order to find out whether the problem of inverter input I changed the strings on both entrances DC-1 and DC-2 - from 08.21.2014 to 01.09.2014. Once I reviewed the information I concluded that the problem is in strings 4 and 5 which were previously tied to DC-1.
    Then I divided string 4 and 5 between the two corresponding DC input DC-1 and DC-2 from 01.09.2014 to 05.09.2014 so I can figure out what exactly makes my string problem. And after finding a string which makes problem to me looked all electrical connections, respectively, and then restored the strings as they were originally. But after two days back again doing the same problems.
    I do not know where could be the problem. Just do it when he wants without any logic.
    Regarding the questions you've answered below:
    -Did u check the seperal String fuses?- Yes, everything is fine
    -Which firmware version do u have at the moment? -
    ARM : V 1.34 (1981)
    DSP-AC : V1.20(AD6A)
    DSP-DC : V1.30 (77CF)
    Parameter: V1.00
    -You wrote, that your open circuit voltage is about 900V... thats really much, and its possible that you blow up ur MPP entrance during cold weather conditions. -> How long does ur problem already exist? – MPP entrance is , ok.
    -Do u have moving shadows on the array? - No
    -What DC start up voltage is programmed? – maybe the firmware version is too old and does not give me what is the DC start up voltage.
    -where does this power plant "live"? ;) Bulgaria , Burgas Province, Sredets Municipality, Svetlina


    I'd be very grateful if you could direct me to where the problem is.


    FotoVOLT_EL1.pdf - PV - http://dox.bg/files/dw?a=2340fb2c7e
    LOG-2014.rar - data PV 2014 year - http://dox.bg/files/dw?a=60f51ce4ec

  • Hello again,


    i watched ur documents and first of all i see the mpp´s equipped with: 3/2/2, Strings, right?
    After that i took a view to ur Log Data, and between 08/31 and 04/09 theres no logging Point about ~230V on DC side.
    Do u have a represental date on which i should care for?


    The only thing i can advice at moment: Update ur machine onto the latest firmware and give a logging feedback...


    use an old usb stick which is not bigger than 1Gb, freshly formated at FAT32, and present a second one at the procedure. Use strictly the Documents, to find at Kaco.de.


    So long at the Moment, Andreas

    Andreas Witt
    Industrieservice und Montage
    Am Dorfplatz 7, 24214 Neudorf
    Tel.: +49 151 44 555 285
    info@pvservice.net
    USt-ID: DE 292086601, Handwerkskammer zu Flensburg



    Dienstleistungen rund um Photovoltaik: Wartung, Repowering, Datenlogging, Direktvermarktung & Redispatch 2.0, Anlagenplanung und -Neubau, Huawei Wechselrichter, Zubehör und PV- Komponenten

  • Well, first of all I can NOT agree that the string setup of your Modules is right. Assuming that you got the Modules listed under http://www.photovoltaikforum.c…s=3&mode=display&id=40791, the open circuit voltage of a string of 22 Modules would be 1100 V at -10°C. Even at 25°C cell temperature you end up at 983 V, so roughly speaking when the cell Temperatur is below 20°C you provide overvoltage to the inverter. The maximum number of modules per String i would advise you would be 20 (taking under consideration that you will most likely not have -10°C in UK but max. -5°C)! Otherwise you definitely risk to destroy your inverter with overvoltage!
    Same problem applies to the MPP voltage, the inverter limit there would be 800 V. Taking module voltages at 25°C is NOT the right way to plan strings!
    After you corrected that, we could check about the "residual" problems. Maybe your current problems are triggered by the wrong wiring, providing overvoltage to the inverter (if you did'nt already damage it). Most likely you already lost your inverter's warranty due to the miswiring.


    Ciao


    Retrerni

  • Hello from Kiel,


    any news?


    Regards, Andreas

    Andreas Witt
    Industrieservice und Montage
    Am Dorfplatz 7, 24214 Neudorf
    Tel.: +49 151 44 555 285
    info@pvservice.net
    USt-ID: DE 292086601, Handwerkskammer zu Flensburg



    Dienstleistungen rund um Photovoltaik: Wartung, Repowering, Datenlogging, Direktvermarktung & Redispatch 2.0, Anlagenplanung und -Neubau, Huawei Wechselrichter, Zubehör und PV- Komponenten