Here is Enphase's answer (or maybe Fronius was answering Enphase): https://enphase.com/en-us/support/arc-fault-demonstration
Also, their literature suggests that the risk of a DC arc fault occuring is far lower due to there being much less DC cabling exposed on the roof. With no long DC home runs, that would obviously lower the probability of an occurrence. I see where they are coming from, but we're talking about severity here, not probability. I have seen a few melted MC4 connectors at the panel to microinverter connection. The results seem to support Enphase's video where the arc is small and possibly intermittent, melting a hole in the connector housing, but falling short of an exposed flame. I think there is a twofold response that a microinverter manufacturer would make. The probability of DC Arc fault is reduced and severity is lower. That's a strong argument. Is anyone aware of a significant fire in a microinverter system caused by a DC arc fault? I assume there are anecdotes out there, but I haven't heard of any. On the flip side, I've seen some pretty gnarled DC conductor bundles melted together on string inverter systems with burned modules above them. That said, I would probably support more safety on the DC side of microinverters. If AC modules weren't so darn expensive, I'd probably go that direction. If PV DC leads were shorter I'd probably mount microinverters to module frames. If integrated AFCI was available on microinverters at a reasonable cost, that would be great. Jason Szumlanski Florida Solar Design Group On Fri, Feb 5, 2021, 5:40 PM Jeremy Coxon <[email protected]> wrote: > Very interesting video, now I know Fronius is pointing fingers at Micro > manufacturers but the demo seems to back up their proposal to scrap the 80V > limit. This is yet another reason we haven’t used many Micro’s on our > systems. > > https://m.youtube.com/watch?v=H3c9GbLhQhY&t=4s > > > Jeremy Coxon NABCEP > Certified MWBE > > Sent from my iPhone > _______________________________________________ > List sponsored by Redwood Alliance > > List Address: [email protected] > > Change listserver email address & settings: > http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org > > There are two list archives for searching. When one doesn't work, try the > other: > https://www.mail-archive.com/[email protected]/ > http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org > > List rules & etiquette: > http://www.re-wrenches.org/etiquette.htm > > Check out or update participant bios: > http://www.members.re-wrenches.org > >
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