Jason, In our territory the utility (PG&E) starting switching to digital smart meters five to ten years ago. In order to function properly with a PV system, meters need to be programmed for Net Energy Metering (NEM). If you run a PV system prior to receiving Permission To Operate (PTO) from the utility, backfed energy may actually register as energy consumed by the property. The meter will still show a little arrow to the left (meaning backfeeding to grid) but they will bill you as if that energy was being consumed. I can't say that all meters work this way, but I can verify that it has happened when some of our customers jumped the gun and turned on their system prior to receiving PTO. This could be a totally separate issue from what you're seeing, but thought I'd just chime in.
Best, August On Thu, Aug 16, 2018 at 2:44 PM Jason Szumlanski < [email protected]> wrote: > I did a little test today and it looks like everything was reading > correctly. Really strange. I took meter readings and times, so I'll go back > in a week or so and compare the meter readings to Enlighten monitoring. All > CTs are correct (I've corrected so many wrong ones at this point that I'm > definitely expert level on that). On this site I actually have two > conductors per CT because there is a meter/main combo feeding both a main > panel inside the garage and a pool subpanel (3/0 and #6 conductors). I > triple checked directionality and line matching. I removed the CTs, checked > for the magnetic inserts, and reinstalled them. Everything checked out. I > considered putting in parallel CTs, but it shouldn't be necessary. > > > To Dave Tedeyan's point, line-to-line matching results in the most errors > we see in the field now. For example, Eaton main breakers criss-cross > inside, so the lugs top and bottom are reversed. I always check the > voltage across the line to load side of the main to double check. > > Now if Enphase would just change the wording of the CT measurement options > in the Installer Toolkit we could all avoid those annoying errors. It > should simply ask if the consumption CTs are on the load or line side of > the interconnection point (breaker or tap). And while on the subject, let > installers change the setting in the Toolkit! > > > > > On Thu, Aug 16, 2018 at 11:53 AM William Miller <[email protected]> > wrote: > >> Friends: >> >> I have seen utilities misappropriate values from their meter to the >> billing. That might explain your discrepancies. >> >> William >> >> On Aug 16, 2018, at 7:57 AM, Lorenzo Ortiz <[email protected]> wrote: >> >> Fun fact: Sometimes the stickers on the CT's are incorrect too. Had that >> happen and took forever to figure out... >> >> On Wed, Aug 15, 2018 at 4:10 PM, Kirpal <[email protected]> wrote: >> >>> Jason...not sure about the Enphase consumption monitoring, if it is done >>> with CT's confirm that your CT's are facing the right direction. Some CT's >>> are directional and perhaps your consumption monitoring could be backwards >>> instead of the utility meter wiring backwards.....Seems like the utility >>> would have noticed incorrect wiring in their can. >>> We use the E Gauge CT clamps for some monitoring and they are >>> directional. I am not familiar with the Enphase versions. >>> >>> >>> Sunny Regards, >>> Kirpal Khalsa >>> Oregon LRT#25 >>> NABCEP Certified PV Installation Professional >>> Oregon Solarworks LLC >>> www.oregonsolarworks.com >>> 541-299-0402 >>> >>> On Wed, Aug 15, 2018 at 4:01 PM, Jason Szumlanski < >>> [email protected]> wrote: >>> >>>> Is it possible for a utility meter to be programmed/wired backward? I >>>> have a client on an Enphase system with production and consumption >>>> monitoring, and the Enphase monitoring is showing solar production exceeded >>>> consumption by 400 kWh for a billing period. However, the meter is reading >>>> almost exactly the opposite. It seems too coincidental. >>>> >>>> I'm going to go out to the site tomorrow to shut down all of the loads >>>> and see what happens when solar is only backfeeding the meter, but I'm >>>> curious how the meters are "programmed" or set up to work. >>>> >>>> Note that the meter was zeroed to start and the initial billing period >>>> readings show DEL exceeded REC by 400 kWh, which matches what was billed >>>> (net usage of positive 400 kWh). >>>> >>>> Jason Szumlanski >>>> >>>> _______________________________________________ >>>> List sponsored by Redwood Alliance >>>> >>>> List Address: [email protected] >>>> >>>> Change listserver email address & settings: >>>> http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org >>>> >>>> List-Archive: >>>> http://www.mail-archive.com/[email protected]/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: [email protected] >>> >>> Change listserver email address & settings: >>> http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org >>> >>> List-Archive: >>> http://www.mail-archive.com/[email protected]/maillist.html >>> >>> List rules & etiquette: >>> www.re-wrenches.org/etiquette.htm >>> >>> Check out or update participant bios: >>> www.members.re-wrenches.org >>> >>> >>> >> >> >> -- >> *Lorenzo Ortiz Commercial PV Designer* >> >> [email protected]* (530) 274-3671* >> >> >> >> <http://californiasolarco.com/referral-program/> >> *Showroom located at: 149 E Main St. Grass Valley, CA 95945* >> >> _______________________________________________ >> List sponsored by Redwood Alliance >> >> List Address: [email protected] >> >> Change listserver email address & settings: >> http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org >> >> List-Archive: >> http://www.mail-archive.com/[email protected]/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: [email protected] >> >> Change listserver email address & settings: >> http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org >> >> List-Archive: >> http://www.mail-archive.com/[email protected]/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: [email protected] > > Change listserver email address & settings: > http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org > > List-Archive: > http://www.mail-archive.com/[email protected]/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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