How about disabling one inverter at a time when the disturbances are happening?
That might narrow it down to it being a single inverter. Through the process of elimination you may be able to find out if it is a single inverter or a combination of inverters that makes it do it. It might be a specific inverter or it might be a specific combination of inverters I have seen APC UPS units click but not activate, in that case it was one inverter off grid and one UPS. Somewhat irritating, I put it where I couldn't hear it to make the problem go away so to speak ! Later, Bob ellison Bob Ellison > On Aug 4, 2014, at 10:29 AM, Carl Adams <swingjun...@gmail.com> wrote: > > Hello Wrenches, > > I have a site which is experiencing nuisance disturbance of the computer UPS > systems at the site. The site owner "suspects" this is due to the PV system > which is a 50 kW system using 6 SMA SunnyBoy inverters. The nuisance > disturbance is a clicking noise in the UPS units. The disturbance is not > enough to cause the UPS to engage, so it seems to be a small disturbance on > the AC power. The site owner "suspects" the inverters are the source of > this disturbance since 1) It seems to only occur when we have a good solar > day. 2) If the inverters are shut down the problem goes away, and if you > start up the inverters the problem exhibits again. > > The site was commissioned in March of 2012 and has had no problems till this > issue last month. In reviewing the event log on Sunny Portal there are no > inverter anomalies. SMA tech support had not run into this issue and had no > ideas, they too agree the inverters are not reporting any anomalies. > > The problem is not persistent but rather intermittent making this harder to > troubleshoot. > > So my questions are > 1) Has anyone else seen this sort of issue before, related to SMA SunnyBoy > inverters. > 2) Can you recommend an AC power monitoring tool which would support > frequency and voltage monitoring on the AC line. Perhaps one data set on the > circuit feeding the computers and another on the inverter output circuit. > > For clarity the six SunnyBoys feed into an AC Combiner panel which backfeeds > into the building main distribution panel. The service is 240V single phase. > > With Regards > Carl Adams, SunRock Solar > NABCEP Certified PV Installer > _______________________________________________ > 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 > _______________________________________________ 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
