[RE-wrenches] UPS disturbance with SMA Inverters
Chris Mason
cometenergysystems at gmail.com
Mon Aug 4 16:29:57 PDT 2014
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 <swingjunkie at 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.burt at glbcc.com> wrote:
>
>> I wonder if the UPS is grumbling about high voltage as the inverters
>> push back current...
>>
>> Glenn
>> ------------------------------
>> From: Carl Adams <swingjunkie at gmail.com>
>> Sent: 8/4/2014 10:29
>> To: RE-wrenches <re-wrenches at 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 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.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 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.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
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org/attachments/20140804/d333827b/attachment-0002.html>
More information about the RE-wrenches
mailing list