Solar Edge major unresolved problem

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  • Treepmeyer
    Junior Member
    • Sep 2022
    • 18

    Solar Edge major unresolved problem

    Hello - I'm new to this forum and am reaching out because I have a major unresolved problem with my on-grid home PV installation. I have a 36 panel 11.9kW DC/10kW AC array rack-mounted about 200 ft from my house. The schematic shows two strings of JASolar JAP72S01 panels with a Solar Edge single phase HD Wave inverter mounted beneath the panels. It went live in December, 2018. Installation was by Midwest Wind and Solar, which is no longer in business.

    In a nutshell, the problem is that voltage creeps up with PV power production leading to inverter shut-down. Solar Edge says the inverter is working properly, the power company says that they are providing (relatively) clean voltage and the (new) installer says that the installation is wired correctly.

    Symptoms are as follows: voltage before system wake-up is 250v, with minor variation. With system wake-up voltage at the inverter climbs with power production. When voltage reaches around 260v the inverter shuts down and voltage drops back to 250v.

    I didn’t notice anything amiss until September, 2021 when I got an unexpected power bill. When I looked at the Solar Edge monitoring data, power production starts to noticeably drop first in March, 2021 and I thought that the problem started around then. I opened up a support case with Solar Edge and it escalated to Tier 3 but in the end they said the inverter is working alright. They suspect installation, but can't say in what way. As Solar Edge pointed out the voltage creep/"grid voltage" problem has been there all along, its just been getting worse. I reviewed the historical monitoring data and in 2020 the voltage frequently exceeded 260v but without the inverter shutting down. The shut-downs I did notice were when power production hit the 10kW limit. Now it shuts down at 260v or less, and for longer. For example, on 10/1/22 the inverter was shut down between 10:44 and 16:28.

    A review of monthly production is interesting and may provide some clues. Production Nov.-Feb. seems to be normal with random variation between all four years of operation. March-Oct., however shows a systematic reduction in power production for 2021 and 2022 compared to the prior two years.Monthly production for these two most recent years is down 10 to 50%. There is one interesting anomaly, July 2022. Looking day-by-day at AC power and voltage graphs I see fewer shutdowns, more stretches when the system appears to be behaving normally. I don't know what to make of these observations, except that there may be a connection with load. I have a geothermal system for heat and air conditioning. It draws a lot of power during cool months and when I run the air conditioning. The location is in southwestern Michigan and with proximity to Lake Michigan we seldom use air conditioning. I cannot correlate my house electrical power consumption with the inverter shutdowns but I do know that last July was uncommonly hot and humid and as a consequence we ran the air conditioning much more than usual. I am neither trained nor experienced in these matters, but I am suspicious of the inverter power management settings, specifically reactive power management.

    The power company, Indiana/Michigan Power, has been quite cooperative. Their troubleshooter has been onsite several times. In December, 2021 he put a data logger on my meter to record voltage being supplied. It recorded normal levels of variation, never exceeding 127v. (I have copies of the log and supplied them to Solar Edge.) They checked grounding, reset their local regulator and re-crimped the house connections to the grid.

    The new Solar Edge authorized installer sent their master electrician onsite. He verified that the wire is #6 and appropriate, and that the rest of the installation is alright. He thinks that the problem is with the ground/neutral of the grid connection to the house. Re-crimping the connections, however, did not solve the problem. Solar Edge, as mentioned above, thinks that the grid supply is OK and that there must be something wrong with the installation but the master electrician said that the installation is fine. Solar Edge has washed their hands of the problem and I am left with what amounts to a $30,000 lawn ornament.

    I would be very grateful for any insight this community could provide.

    Tom Reepmeyer


  • Mike 134
    Solar Fanatic
    • Jan 2022
    • 393

    #2
    Originally posted by Treepmeyer
    Hello - I'm new to this forum and am reaching out because I have a major unresolved problem with my on-grid home PV installation. I have a 36 panel 11.9kW DC/10kW AC array rack-mounted about 200 ft from my house. The schematic shows two strings of JASolar JAP72S01 panels with a Solar Edge single phase HD Wave inverter mounted beneath the panels. It went live in December, 2018. Installation was by Midwest Wind and Solar, which is no longer in business.

    In a nutshell, the problem is that voltage creeps up with PV power production leading to inverter shut-down. Solar Edge says the inverter is working properly, the power company says that they are providing (relatively) clean voltage and the (new) installer says that the installation is wired correctly.

    Symptoms are as follows: voltage before system wake-up is 250v, with minor variation. With system wake-up voltage at the inverter climbs with power production. When voltage reaches around 260v the inverter shuts down and voltage drops back to 250v.

    I didn’t notice anything amiss until September, 2021 when I got an unexpected power bill. When I looked at the Solar Edge monitoring data, power production starts to noticeably drop first in March, 2021 and I thought that the problem started around then. I opened up a support case with Solar Edge and it escalated to Tier 3 but in the end they said the inverter is working alright. They suspect installation, but can't say in what way. As Solar Edge pointed out the voltage creep/"grid voltage" problem has been there all along, its just been getting worse. I reviewed the historical monitoring data and in 2020 the voltage frequently exceeded 260v but without the inverter shutting down. The shut-downs I did notice were when power production hit the 10kW limit. Now it shuts down at 260v or less, and for longer. For example, on 10/1/22 the inverter was shut down between 10:44 and 16:28.

    A review of monthly production is interesting and may provide some clues. Production Nov.-Feb. seems to be normal with random variation between all four years of operation. March-Oct., however shows a systematic reduction in power production for 2021 and 2022 compared to the prior two years.Monthly production for these two most recent years is down 10 to 50%. There is one interesting anomaly, July 2022. Looking day-by-day at AC power and voltage graphs I see fewer shutdowns, more stretches when the system appears to be behaving normally. I don't know what to make of these observations, except that there may be a connection with load. I have a geothermal system for heat and air conditioning. It draws a lot of power during cool months and when I run the air conditioning. The location is in southwestern Michigan and with proximity to Lake Michigan we seldom use air conditioning. I cannot correlate my house electrical power consumption with the inverter shutdowns but I do know that last July was uncommonly hot and humid and as a consequence we ran the air conditioning much more than usual. I am neither trained nor experienced in these matters, but I am suspicious of the inverter power management settings, specifically reactive power management.

    The power company, Indiana/Michigan Power, has been quite cooperative. Their troubleshooter has been onsite several times. In December, 2021 he put a data logger on my meter to record voltage being supplied. It recorded normal levels of variation, never exceeding 127v. (I have copies of the log and supplied them to Solar Edge.) They checked grounding, reset their local regulator and re-crimped the house connections to the grid.

    The new Solar Edge authorized installer sent their master electrician onsite. He verified that the wire is #6 and appropriate, and that the rest of the installation is alright. He thinks that the problem is with the ground/neutral of the grid connection to the house. Re-crimping the connections, however, did not solve the problem. Solar Edge, as mentioned above, thinks that the grid supply is OK and that there must be something wrong with the installation but the master electrician said that the installation is fine. Solar Edge has washed their hands of the problem and I am left with what amounts to a $30,000 lawn ornament.

    I would be very grateful for any insight this community could provide.

    Tom Reepmeyer

    Disclaimer here I have never troubleshot a solar edge system.

    I highlighted in red what caught my eye. If the problem was on the power company side, why would the inverter being on or off effect your incoming voltage? It syncs to the grid. Where exactly are you taking those voltage measurements?

    Comment

    • Treepmeyer
      Junior Member
      • Sep 2022
      • 18

      #3
      The data logger the power company used was put on the house meter for a week in Dec., 2021. It measured voltage around 125v +/- 1 volt. Peak was 127v. I measured pre-wake up voltage at my house panel with my multimeter. All other voltage measurements are taken from the Solar Edge monitoring web site for my installation. I recently confirmed a couple of high voltage measurements reported by Solar Edge with my multimeter at the house panel. The house panel measurements were within 2v of the voltage reported by Solar Edge.

      Comment

      • Treepmeyer
        Junior Member
        • Sep 2022
        • 18

        #4
        The installer master electrician thought that the problem was with the power company ground/neutral connections to my house. I believe that we have now ruled that out. As I stated, Solar Edge accepts the power company data logger results showing that grid power is not surging or peaking outside of normal parameters. I, too, think that is correct (at least as of 12/21 when the data were collected). Are there conditions in which the inverter does not sync to the grid?

        Comment

        • solarix
          Super Moderator
          • Apr 2015
          • 1415

          #5
          This is why we try mount inverters close to the service and minimize the wire length and voltage drop.
          One work around is it is possible to get special permission from the inverter company to open up the input voltage range parameter to keep it from tripping off.
          I've gone round and round with utilities like this a couple of times, and they always deny that its their fault. Could well be voltage spikes that are hard to catch.
          Another SolarEdge nightmare if you want my opinion....
          Last edited by solarix; 10-04-2022, 08:38 PM.
          BSEE, R11, NABCEP, Chevy BoltEV, >3000kW installed

          Comment

          • Treepmeyer
            Junior Member
            • Sep 2022
            • 18

            #6
            Sorry, but I don't have a voltage drop. I have a gradual voltage increase, no spikes. The voltage increase correlates closely with panel power production. When the panels are not producing power the voltage is 250v +/-2v. As PV power production increases, so does voltage until the inverter protection kicks in around 260v. When the inverter shuts down voltage drops back to a steady 250v. No spikes!

            Comment

            • Mike 134
              Solar Fanatic
              • Jan 2022
              • 393

              #7
              Just out of curiosity since your inverter puts out 40 amps and is 200 feet from the service panel is your wire size at least a #4 copper between them?

              Comment

              • Treepmeyer
                Junior Member
                • Sep 2022
                • 18

                #8
                It is #6 which both Solar Edge and the installer's electrician said is appropriate.

                Comment

                • SunEagle
                  Super Moderator
                  • Oct 2012
                  • 15126

                  #9
                  Originally posted by Treepmeyer
                  It is #6 which both Solar Edge and the installer's electrician said is appropriate.
                  That #6 wire will not carry 40amps or work to stay below 2% voltage drop over 200ft. I think the installer's electrician is wrong.

                  Comment

                  • Treepmeyer
                    Junior Member
                    • Sep 2022
                    • 18

                    #10
                    Solar Edge, the original installer, and the current installer's master electrician are all wrong?

                    Let's assume that the wire is undersized, what would the effect be? Would it heat up, with increased resistance? Would that result in a voltage increase? And would that be proportional to the amperage produced by the array? I'm trying to understand how the symptoms we observe can be explained.

                    Comment

                    • SunEagle
                      Super Moderator
                      • Oct 2012
                      • 15126

                      #11
                      Originally posted by Treepmeyer
                      Solar Edge, the original installer, and the current installer's master electrician are all wrong?

                      Let's assume that the wire is undersized, what would the effect be? Would it heat up, with increased resistance? Would that result in a voltage increase? And would that be proportional to the amperage produced by the array? I'm trying to understand how the symptoms we observe can be explained.
                      They may have errored on the lower cost side. While a #6 should be able to carry 40amps my fear is that you may exceed the 2% voltage drop allowed by the NEC. That could also cause issues on the input side of the panel which could lead to over heating.

                      And yes a voltage drop calculation is based on the amount of amps the distance and the resistance of the wire. If it was for a DC voltage calculation it would need to include both the + and - distance runs. Which is probably close to 400 feet.

                      Since it is an AC voltage run you still might be a little shy of the voltage drop allowed

                      Comment

                      • Mike 134
                        Solar Fanatic
                        • Jan 2022
                        • 393

                        #12
                        Originally posted by Treepmeyer
                        Solar Edge, the original installer, and the current installer's master electrician are all wrong? Depends on the allowed voltage drop. Did anyone tell solar edge the wire size and distances?

                        Let's assume that the wire is undersized, what would the effect be? Would it heat up, with increased resistance? Would that result in a voltage increase? And would that be proportional to the amperage produced by the array? I'm trying to understand how the symptoms we observe can be explained.
                        Your #6 will have a voltage drop of 3.1% or almost 8 volts. Perfectly acceptable in the real world. NEC code "recommends" no more than 3% you're a tick over.

                        Your questions should be asked to the solar edge tech support how a 200' run with 3% voltage drop will impact their inverter.


                        Comment

                        • peakbagger
                          Solar Fanatic
                          • Jun 2010
                          • 1565

                          #13
                          FWIW I have three arrays that feed into a subpanel and then the subpanel is tied to my main panel via a wire run that goes out to a utility disconnect switch, a production meter and then on to the panel. When I first installed it I reused some existing wires that were borderline for the new application and I was having occasional issues with inverters staying synched to the grid. It wasnt all the time but on occasion it took awhile. I ran the numbers on sizing and replaced the wires with a larger gauge and the problem went away.

                          Usually inverters are set up with tighter than standard voltage range, there is usually an option through the installer of the manufacturer to bump up that range if things are acting weird. I have a friend that had bad power from the utility and that tided hm over until the utility hooked up a power quality analyzer and found out problems with their grid. This seems to happen far more in the country than in the city.

                          Comment

                          • oregon_phil
                            Solar Fanatic
                            • Jan 2019
                            • 497

                            #14
                            Good point about tighter specs. For my SMA 7.7-40 grid parameters, there is a set of parameters to follow when the inverter is up and running and another set of voltage parameters to follow after a fault occurs. Lower reconnection limit= 106VAC, Upper reconnection limit = 127 VAC (obviously one leg). I couldn't find anything in SE documentation that details these exact parameters however.

                            I think my SMA inverter would act just like the OP's inverter in his situation due to the voltage reconnection limits.

                            Comment

                            • Treepmeyer
                              Junior Member
                              • Sep 2022
                              • 18

                              #15
                              I have a quote from my current installer to replace the #6 line with a #4 line for $4100. That was what the service electrician recommended initially. Then the installer's master electrician stepped in arguing that the #6 wire was OK and the problem was likely the power company's ground/neutral connection. He was trying to save me some money. But then the tier 3 Solar Edge service people agreed that the #6 line was OK, so I discounted the line guage as the problem. Sounds like everyone here agrees that I need to go ahead with the #4 line replacement.

                              Comment

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