Hi James, I assume this is an intermittent fault? Do you have Sunpower modules? We have a very small percentage of Sunpower systems (E20-327 modules) with SMA TL-22 inverters that have had intermittent arc fault issues. On some of them we have even replaced the inverter, but the issue still happens. This does not seem to happen at all with other modules. At one site we have even replaced the inverters, took all the modules off the roof and checked the connections and it still arc faulted. Sunpower eventually had us replace nearly half the modules. It has not arc faulted since then, but that was less than 6 months ago and some of these will arc fault about once per year.
Cheers, Dave *--* *Dave Tedeyan* *Senior Engineer* *Taitem Engineering, PC* 10 Verizon Lane, Lansing, NY 14882 Voice: (607) 930-3481 x6 www.taitem.com On Thu, Jan 25, 2018 at 8:52 AM, Steven Lawrence <lawrenceste...@gmail.com> wrote: > Hi James, > > Is the solectria combiner actually combining strings so you have one input > into the SMA inverter? If so, did SMA approve arc fault detection at that > high current? From what I understand, arc fault detection doesn't work on > strings greater than 20A. > > In the solectria box, I'm assuming there is a contactor in there, > correct? Do you have coils of wire inside from the power supply to the > contactor? I have seen instances where coiled wire was generated the noise > itself. Is the wire from the power supply to the contactor shielded? > > > From: James Rudolph <jamesrudolp...@gmail.com> >> >> >> Aloha Wrenches, >> >> I have a issue I would like to throw at the group. >> >> We have a SMA 24000TL-US with a Solectria Rapid Shut Down Combiner. >> The inverter keeps faulting the AFCI. We megged the strings,and checked >> all >> connections on all components. So we are confident that the issue is not >> related, or connected to all of that. We also swapped out the RSB. >> >> I really can't disclose where the building is located because its >> military, >> and most of their IT infrastructure happens to be in this building as >> well. >> >> I know from research, and tech support that this happens sometimes with RF >> signals,metal roofs,and communications antennas,etc. >> >> SMA is suggesting we could re-run the stings so that we mitigate the >> possibility that the strings are picking up this noise and triggering the >> AFCI, or get clearance to disable that feature on the inverter. >> >> Due to safety issues I'm sure the last option is not on the table. >> >> We can also place any given sting on the combiner and it will work fine >> with no faults up to four stings. Once we place more than four strings on >> the combiner the inverter will fault. >> >> Since we are still on the 2008 NEC in Hawaii this is our first run in with >> the Rapid Shut Downs too. Maybe somehow this is tied into the issue? >> >> Anyone have thoughts, or experience with this type of issue? >> >> >> Mahalo Nui, >> >> >> *James B. Rudolph* >> >> *Hawaii Unifed* >> >> *Director of Energy* >> >> *ES Electrician # 10816* >> >> *NABCEP Certified PV Installer # 091209-155* >> -------------- next part -------------- >> An HTML attachment was scrubbed... >> URL: <http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenc >> hes.org/attachments/20180124/455d31c5/attachment-0001.html> >> > > > _______________________________________________ > List sponsored by Redwood Alliance > > List Address: RE-wrenches@lists.re-wrenches.org > > Change listserver email address & settings: > http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org > > List-Archive: http://www.mail-archive.com/re-wrenches@lists.re-wrenches. > org/maillist.html > > List rules & etiquette: > www.re-wrenches.org/etiquette.htm > > Check out or update participant bios: > www.members.re-wrenches.org > > >
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