A bit off topic, BUT testing equipment from these folks is a really great way to go;www.trsrentelco.com <http://www.trsrentelco.com/>. GREAT, PROMPT, cost effective tool rental and service. I rent the Fluke 1735 or the 1738 power logger for a month its under $300.00 > On Jan 23, 2020, at 3:16 PM, William Miller <[email protected]> wrote: > > Colleagues: > > In a recent post about some AC GFI tripping problems, I mentioned I am > measuring some high THD readings in certain scenarios—the highest being when > the generator is charging at high percentages: > > Inverter only: 2.5% THD > Gen Max: 19% THD > Gen 5 Amps: 8% THD > > I measured the THD using a Fluke VR1710 <x-msg://22/TJ3fTpspG2DGCzC>. This > is a handy little gizmo and pretty expensive considering its size. The > device has limitations: > 1. It is cord connected. > 2. Results cannot be viewed in real-time. > 3. It measures voltage parameters only. > > Here are my questions: > > 1. Has anyone here had to consider problems with high THD in any off-grid > scenarios? > 2. What readings are normal? > 3. What is the significance of voltage harmonics versus current harmonics? > 4. What instruments are you using to measure THD? > 5. Has anyone seen high THD causing AC GFI tripping? > 6. What other symptoms might occur with high THD? > > Tip: The reason we first started suspecting high THD is that cheap voltmeters > registered abnormally high (including the onboard Radian metering) during > periods of high THD, while true RMS meters (Fluke 87) continued to measure > normal AC voltages. If you experience this situation, high THD is suspect. > > Answers are always gratefully appreciated. > > William Miller > > PS: If you are receiving a BCC of this email, it is because you are part of > the team working on this problem. The message is directed to an industry > forum in hopes of gleaning additional knowledge. I will share any results I > receive. > > Wm > > Miller Solar > 17395 Oak Road, Atascadero, CA 93422 > 805-438-5600 > www.millersolar.com <http://www.millersolar.com/> > CA Lic. 773985 > > _______________________________________________ > List sponsored by Redwood Alliance > > List Address: [email protected] > <mailto:[email protected]> > > Change listserver email address & settings: > http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org > <http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org> > > List-Archive: > http://www.mail-archive.com/[email protected]/maillist.html > <http://www.mail-archive.com/[email protected]/maillist.html> > > List rules & etiquette: > www.re-wrenches.org/etiquette.htm <http://www.re-wrenches.org/etiquette.htm> > > Check out or update participant bios: > www.members.re-wrenches.org <http://www.members.re-wrenches.org/> > [email protected] > <blocked::mailto:[email protected]%22%20%5Co%20%22blocked::mailto:[email protected]> > www.SWNL.net > <blocked::http://www.swnl.net/%22%20%5Co%20%22blocked::http://www.swnl.net/> > Solarwinds Northernlights > Serving Mid Coast Maine & Northern California > 207-832-7574 Cl. 610-517-8401 > > Blair "TUMP" May > ******** MAINE'S CHARTER ******** > NABCEP "Certified PV Installer" > > ******** MAINE'S CHARTER ******** > Trace Xantrex "Certified" Dealer / Installer" >
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