It would be good to put a volt meter at the input to the UPS confirm input voltage is within range at the time there is an issue. If volts are high there is a problem between that location and as far as the transformer. A scope would help to see noise on the AC side but an old AM radio may do the same to detect noise on the line. On Aug 4, 2014 1:30 PM, "Chris Mason" <cometenergysyst...@gmail.com> wrote:
> Is it possible that the UPS issue is raised voltage, causing the UPS > voltage regulator to switch settings? A large amount of solar on a circuit > can raise the voltage in the system at full sun. I would rent a Fluke > Energy Analyzer and leave it in place for a number of days to see how the > voltage, current and power factor varies with the inverter output. > > > On Mon, Aug 4, 2014 at 5:11 PM, Carl Adams <swingjun...@gmail.com> wrote: > >> Bob, Ray, Glenn, >> >> Thanks for the responses. We could cycle through the inverters and see >> if it is one, or some combinations of inverters, which is causing the >> problem. This results in a minimum of 6 trials. If it is a combination of >> inverters many more. >> >> Any feedback on the idea of monitoring the AC circuits; computer feed and >> combined inverter output? Seems to me this might provide a one step >> correlation between the event and the cause. Just not sure what equipment >> to suggest for this. >> >> Could be there is some other cause, unrelated to the inverters. AC unit >> kicking on, etc. Though they do not see any lights dimiming/brightening, >> or any other notable change in electrical equipment at the sight. >> >> >> >> On Mon, Aug 4, 2014 at 1:03 PM, Glenn Burt <glenn.b...@glbcc.com> wrote: >> >>> I wonder if the UPS is grumbling about high voltage as the inverters >>> push back current... >>> >>> Glenn >>> ------------------------------ >>> From: Carl Adams <swingjun...@gmail.com> >>> Sent: 8/4/2014 10:29 >>> To: RE-wrenches <re-wrenches@lists.re-wrenches.org> >>> Subject: [RE-wrenches] UPS disturbance with SMA Inverters >>> >>> 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 >> >> >> > > > -- > Chris Mason > NABCEP Certified Solar PV Installer™ > Solar Design Engineer > Generac Generators Industrial technician > > www.cometsolar.com <http://www.cometenergysystems.com> > 264.235.5670 > 869.662.5670 > Skype: netconcepts > > _______________________________________________ > 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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