Just a note: The PV150 does insulation testing as part of the series of "one-button" tests. They include:
- Earth / ground continuity - Open circuit voltage - Short circuit current - Insulation resistance - DC operating power - Operational current - Polarity - Earth test lead null The American solar industry really should start implementing the IEC 62446 standard on system commissioning and testing standard for all PV installations. http://www.seawardsolar.com/downloads/Standardizing-PV-System-Documentation_and_Verification.pdf On Mon, Oct 5, 2015 at 11:08 AM, Bill Hoffer <suneng...@gmail.com> wrote: > Bill > > Performance verification would be your first test that can be done with 2 > clamp on meters ( idealy two Power meters like the Seaward Clamp Power > Meter ) , ie testing under load knowing the irradiance and cell > temperatures and measuring watts in and watts out of the inverter. With > that data you should be able to tell if the array is at maximum power point > and/or if the Inverter is operating within spec. You should account for > irradiance, cell temperature and Light Induced Power degradation ( 1% loss > per year unless module manufacturer warranty defines it differently), > voltage drop soiling etc... > > IMHO Curve tracers are a huge investment in money and time to learn how to > get meaningful information out of them. Also the 3 choices currently > available each have limitations that make it hard to decide which is the > best solution. That would be my last investment on the list of test tools. > Better to invest in a Insulation Resistance Tester and then something like > the PV150 tester ( which can also do DC Power measurements). > > Bill > > On Sun, Oct 4, 2015 at 6:56 PM, frenergy <frene...@psln.com> wrote: > >> Wrenches, >> >> As time passeth, we're bumping more into older PVs/arrays that >> have questionable outputs. After minimizing the variables (dust, temps, >> sun angle, wiring, expected deterioration with age, etc) and still coming >> up with low numbers. Testing individual PVs' Voc and Isc don't seem to >> tell the whole story as they often look good. >> >> Would not a definitive test be to wire a suspect PV to an >> inexpensive mppt CC (oxymoron?) and then to an orphaned battery. The >> battery would have to have a mondo (surplus) rheostat paralleled to it to >> maintain a steady voltage during the test. With appropriate metering in >> place, you would then have Vmmp and Immp as the rheostat is tweaked to hold >> a steady batt voltage and the CC finds the knee. >> >> Help me here. I know its a little spendy to cobble up but the >> value of nailing an offender might be worth it. Am I missing something? >> Is it common for inverters to fall off in output gradually? >> >> Bill >> Feather River Solar Electric >> >> _______________________________________________ >> 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 >> >> > > > -- > William Hoffer > 161 SE Fourth Ave > P.O. Box 1823 > White Salmon, WA 98672-1823 > suneng...@gmail.com <bhof...@sunergyengineeringservices.com> > > > _______________________________________________ > 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
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