Hi August, The inverter is an Sunny Boy 7700TL-US-22 with REC 280 TP modules. The array and roof are grounded.
There are large compressors on the system for heat pump and A/C. The array is on an estimated 2600 sq ft metal roof. The system had no issues for months after the installation and then the arc fault device started tripping and wouldn't stay reset. The system was operating normally again by the time we got there. Drake At 06:16 PM 3/23/2016, you wrote:
Hi Drake,  What model SMA inverter(s) and modules do you have? We had one case where a MC4 connector under the array was not making good contact. It was not seated properly when the installer made up the connector and the arc fault sensor in the inverter did its job. We had another site where some electrical noise on the AC side, presumably a sump pump, caused the issue and we could not solve it so had to switch to another inverter manufacturer. There were other cases where the impedance or other electrical characteristics of the solar modules where the likely culprit.  Is your roof and array totally equipment grounded?  Best,  August  From: RE-wrenches [mailto:[email protected]] On Behalf Of Drake Sent: Wednesday, March 23, 2016 2:08 PM To: <mailto:[email protected]>[email protected] Subject: [RE-wrenches] AFCI trip on metal roof  Hello Wrenches, We have a project with an array on a large metal roof. The AFCI has been tripping. Investigating the system, there is no evidence of any arcing: the wiring and connections are all very tight. SMA tech support says it is likely that the nuisance tripping comes from electrical noise getting picked up by the large metal roof. What has been your overall experience with nuisance tripping of arc fault protection? What were the suspected causes? What was the solution? Thanks, Drake Drake Chamberlin Athens Electric LLC OH License 44810 CO License 3773 NABCEP Certified Solar PV 740-448-7328 <http://athens-electric.com/>http://athens-electric.com/ <https://www.avast.com/sig-email?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=emailclient&utm_term=oa-2115-v2-c> [] No threats detected. <https://www.avast.com/sig-email?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=emailclient&utm_term=oa-2115-v2-c>www.avast.com  _______________________________________________ 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 List-Archive: http://www.mail-archive.com/[email protected]/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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