[RE-wrenches] SMA Arc-Fault

[Matt Partymiller]

Dave,

We have seen false arc-faults on numerous SMA installs.  I have at least
two where we have spent longer troubleshooting than installing the array
(basically removed and re-installed all components).  SMA is very little
help and ultimately encourages us to deactivate the arc-fault feature,
against code requirements.  In one instance we were able to talk SMA into
upgrading a -22 unit to their new -US unit.  That hasn't been installed
long but no issues yet.

Our arrays with older Tigo optimizers and newer SMAs are entirely
hopeless.  Tigo has just advised us to use -22 SMAs only.

If the arc fault is intermittent don't be afraid to conclude the problem
is the inverter, not your install.

Good luck.

Matt



On Thu, November 10, 2016 1:14 pm, Dave Tedeyan wrote:
> Hi All,
>
>
> Maybe someone will have some ideas for why a couple inverters keep arc
> faulting:
>
>
> -There are two SB7000TL-22 inverters, Sunpower branded.
> -3 Strings of 7 SPR-327's to each inverter. Kept separate until the
> inverter. -Ground mount about 50' from the shed where the inverters are
> located (indoors)
> -Simple grid connected system, no batteries.
> -There is a whole house generator co-located in the shed.
> -We interconnect by using piercing taps on the line side of the generator
> transfer switch -There has been only one power outage there since the
> system was installed in April, but the generator fires up weekly.
>
> -The arc faults have been happening on both inverters. Sometimes only one
>  at a time, sometimes both will go within a day of each other. -The events
> have been approximately one a month, but sometimes more, sometimes less.
>
> -We have already checked every single connection in the system twice, by
> two different people. -We have replaced the underground wires (and they
> looked just fine) -We have replaced all home runs.
> -We have replaced both inverters.
> -Arc faults are still happening.
> -Arc faults are not always on the same day/time of the week.
>
>
> I am wondering if this can be caused by the generator?
> Has anyone run into a situation like this or something similar?
>
>
> Thanks for your help,
> Dave
>
>
> *--*
>
>
>
> *Dave Tedeyan*
> *Project Engineer*
>
>
> *Taitem Engineering, PC*
> 109 S. Albany Street, Ithaca, NY 14850
> Voice: (607) 277-1118 x121
> www.taitem.com _______________________________________________
> List sponsored by Redwood Alliance
>
>
> List Address: RE-wrenches at 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.ht
> ml
>
> List rules & etiquette:
> www.re-wrenches.org/etiquette.htm
>
> Check out or update participant bios:
> www.members.re-wrenches.org
>
>


Matthew Partymiller
Solar Energy Solutions LLC
(877) 312-7456
matt at solar-energy-solutions.com