Re: [RE-wrenches] PV water pumping
Jay is correct about the economics, but sometimes we must live with them as the only way to increase daily water production. However when the tracker fails they will not be making the daily need anymore and it is far more likely to be left dead than even batteries. In developing communities I have often used a village tracker, a manually tracked array that anyone walking by can move to the sun. Along the line of Buddhist Prayer Wheels that are kept spinning by passerby's. As an aside I once did a 40kW grid-tied PV system for a temple to offset the load of the countless motors spinning their Prayer Wheels (not enough people passing to keep them all spinning). From the Solar, Wind and Hydro powered office of Jeff Oldham/Regenerative SOLutions Dermatologists Hate Her Local Mom Reveals $5 Trick to Erase Wrinkles. Shocking Results Exposed http://thirdpartyoffers.juno.com/TGL3131/4d556959973be205a16st03vuc___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] Solmetric SunEye upgrade?
Yes, very sensitive to nearby EMFs. And the bugger mistakes clouds for shading! marco Wrenches, I'm considering upgrading my old SunEye 100 to the model 210 this year. Even with the trade-in credit, the 210 costs more than the original SunEye did. I'm interested in hearing from those of you who have taken this step. Is it worth it? What are the most significant benefits to you? While we're on the subject of the SunEye, let's talk about some of the tricks to using this tool. I've found the built-in compass to be very sensitive to nearby metal, even nails under comp shingles. I find it more accurate to get the orientation of a site from Google maps and the azimuth angle finder on the Solmetric website: http://www1.solmetric.com/tools/RoofAzimTool.htm Then I update the azimuth angle in the software to the accurate measurement from Solmetric/Google, but it's still a tedious process to get the tool oriented as accurately as possible on site. That's part of why I'm interested in the 210, because its more rectangular shaped body would be a bit easier to orient on site with a protractor if the magnetic compass is having fits. Am I being too fussy with this? As I see it, a 10-degree azimuth error will throw off your shading analysis enough to be significant in certain scenarios, e.g. does the shade from that tall tree stop at 9am or 10am? Regards, -Hans ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org _ No virus found in this message. Checked by AVG - www.avg.com Version: 10.0.1204 / Virus Database: 1435/3435 - Release Date: 02/10/11 ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
[RE-wrenches] Calculation of Maximum Circuit Current
In studying for NABCEP certification I am a little confused about whether you multiply the short circuit current by 1.25 once or twice (1.56) in order to calculate maximum circuit current in determining wire size. Same for overcurrent protection. I have always done it twice (1.56) for both PV source circuit and PV output circuit. Once for over irradiance and once for continuous use. But a handout at a recent seminar that I went to totally confused me. Can anyone spell it out very clearly? Thank you. Larry Liesner Wirewiz Westport, CT Phone: 203-644-2404 Fax: 203-557-0556 wire...@gmail.com www.wire-wiz.com ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] Solmetric SunEye upgrade?
I recently went through the same exercise as you are about three months ago. Our Site Surveyors had mangles the jack on the Model 100 body to the point that there was less than a 50% chance that (1) the unit would charge up adequately and (2) we could download the session to our computer. The fix of course was to send the unit back to Solmetric and have them fix the jack. Well, their response was that the HP iPaq PDA (the heart of the SunEye) was now discontinued and they weren't sure that they could find one. They offered instead the new model with a paltry trade-in allowance (which they have since increased). I told them that I found a new iPaq on EBay, and I would purchase it and ship it to them. They rejected that solution because of warranty issues. I countered that I was just trying to be helpful and that they could buy the iPaq on EBay themselves (they didn't like that idea either). They kept bringing up the upgrade to the 210, and at one point increased the trade-in. I still wanted the old SunEye fixed because it fulfilled our needs and I didn't want to shell out another $1,500. Well, Solmetric finally fixed our unit for a tidy sum (maybe $400, I don't remember exactly) and it continues to see 2-3X weekly usage. We have given up using the compass, precisely because every mapping app shows true North from Google Maps to the Thomas Guide. I'm pretty sure that a +/- 10 degree error will not create a large impact on production (without shading issues). With shading it could be important. With all the mapping apps, we feel pretty confident we can figure out true south once we get on the roof before the Site Survey (look at Google Earth and figure out a prominent landscape feature from the roof beforehand). I haven't held the 210 in my hands so I can't vouch for its increased human interface, and I don't understand any of the new features, so we are pretty happy in our ignorance. It may be more to do that I really appreciate well-made equipment and I tend to keep them (and fix them) for a long time. Heck I still have a 1986 Audi Quattro... Peter T. Parrish, Ph.D., President California Solar Engineering, Inc. 820 Cynthia Ave., Los Angeles, CA 90065 CA Lic. 854779, NABCEP Cert. 031806-26 peter.parr...@calsolareng.com Ph 323-258-8883, Mobile 323-839-6108, Fax 323-258-8885 -Original Message- From: re-wrenches-boun...@lists.re-wrenches.org [mailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of Hans Frederickson Sent: Friday, February 11, 2011 10:07 AM To: 'RE-wrenches' Subject: [RE-wrenches] Solmetric SunEye upgrade? Wrenches, I'm considering upgrading my old SunEye 100 to the model 210 this year. Even with the trade-in credit, the 210 costs more than the original SunEye did. I'm interested in hearing from those of you who have taken this step. Is it worth it? What are the most significant benefits to you? While we're on the subject of the SunEye, let's talk about some of the tricks to using this tool. I've found the built-in compass to be very sensitive to nearby metal, even nails under comp shingles. I find it more accurate to get the orientation of a site from Google maps and the azimuth angle finder on the Solmetric website: http://www1.solmetric.com/tools/RoofAzimTool.htm Then I update the azimuth angle in the software to the accurate measurement from Solmetric/Google, but it's still a tedious process to get the tool oriented as accurately as possible on site. That's part of why I'm interested in the 210, because its more rectangular shaped body would be a bit easier to orient on site with a protractor if the magnetic compass is having fits. Am I being too fussy with this? As I see it, a 10-degree azimuth error will throw off your shading analysis enough to be significant in certain scenarios, e.g. does the shade from that tall tree stop at 9am or 10am? Regards, -Hans ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] Calculation of Maximum Circuit Current
Maximum current is defined in 690.8(A) as Isc x 1.25. Minimum OCPD size is defined in 690.8(B) as maximum current x 1.25 (Isc x 1.56). The maximum size, for PV source circuits, is the module maximum series fuse size. Required conductor ampacity is the greater of Isc x 1.56 or Isc x 1.25 with all conditions of use factors (and the conductor must be protected by the OCPD under conditions of use). Brian On Fri, Feb 11, 2011 at 11:03 AM, wire...@gmail.com wrote: In studying for NABCEP certification I am a little confused about whether you multiply the short circuit current by 1.25 once or twice (1.56) in order to calculate maximum circuit current in determining wire size. Same for overcurrent protection. I have always done it twice (1.56) for both PV source circuit and PV output circuit. Once for over irradiance and once for continuous use. But a handout at a recent seminar that I went to totally confused me. Can anyone spell it out very clearly? Thank you. Larry Liesner Wirewiz Westport, CT Phone: 203-644-2404 Fax: 203-557-0556 wire...@gmail.com www.wire-wiz.com ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org -- Brian Mehalic NABCEP Certified Solar PV Installer™ PV Online Coordinator Solar Energy International Carbondale, CO 81623 http://www.solarenergy.org ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] Calculation of Maximum Circuit Current
So you pick a conductor size from 310.16 (90 deg column) and then adjust for conditions of use. That number has to be greater than Isc x 1.25. OCPD has to protect Isc x 1.56. On Fri, Feb 11, 2011 at 2:18 PM, Brian Mehalic br...@solarenergy.orgwrote: Maximum current is defined in 690.8(A) as Isc x 1.25. Minimum OCPD size is defined in 690.8(B) as maximum current x 1.25 (Isc x 1.56). The maximum size, for PV source circuits, is the module maximum series fuse size. Required conductor ampacity is the greater of Isc x 1.56 or Isc x 1.25 with all conditions of use factors (and the conductor must be protected by the OCPD under conditions of use). Brian On Fri, Feb 11, 2011 at 11:03 AM, wire...@gmail.com wrote: In studying for NABCEP certification I am a little confused about whether you multiply the short circuit current by 1.25 once or twice (1.56) in order to calculate maximum circuit current in determining wire size. Same for overcurrent protection. I have always done it twice (1.56) for both PV source circuit and PV output circuit. Once for over irradiance and once for continuous use. But a handout at a recent seminar that I went to totally confused me. Can anyone spell it out very clearly? Thank you. Larry Liesner Wirewiz Westport, CT Phone: 203-644-2404 Fax: 203-557-0556 wire...@gmail.com www.wire-wiz.com ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org -- Brian Mehalic NABCEP Certified Solar PV Installer™ PV Online Coordinator Solar Energy International Carbondale, CO 81623 http://www.solarenergy.org ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org -- Larry Liesner System Design Elektron Solar, LLC 16 Ketchum St. Westport, CT 06880 203-557-3127 (office) 203-644-2404 (cell) 203-549-0977 (fax) wire...@gmail.com ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] Calculation of Maximum Circuit Current
Short answer: DC/PV side two factors of 1.25; AC side one factor. Reasons: the common factor of 1.25 is due to the treatment of PV systems as continuous sources of power, the second factor of 1.25 is for the cloud effect. It is entirely possible to get more than 1,000 W/m^2 on a PV module if there are large cumulus clouds that don't block the sunlight but act as pretty good reflectors of sunlight. As a result you need to increase Isc (times the number of combined strings if that is the case) by 1.56, and all computed AC currents by 1.25. Same goes for and switches and OCPDs. Then of course you need to compute the ampacity of the wire being used, taking care to apply the temperature correction and conduit fill correction before comparing to the maximum current calculation. - Peter Peter T. Parrish, Ph.D., President California Solar Engineering, Inc. 820 Cynthia Ave., Los Angeles, CA 90065 CA Lic. 854779, NABCEP Cert. 031806-26 peter.parr...@calsolareng.com Ph 323-258-8883, Mobile 323-839-6108, Fax 323-258-8885 -Original Message- From: re-wrenches-boun...@lists.re-wrenches.org [mailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of wire...@gmail.com Sent: Friday, February 11, 2011 11:03 AM To: RE-wrenches@lists.re-wrenches.org Subject: [RE-wrenches] Calculation of Maximum Circuit Current In studying for NABCEP certification I am a little confused about whether you multiply the short circuit current by 1.25 once or twice (1.56) in order to calculate maximum circuit current in determining wire size. Same for overcurrent protection. I have always done it twice (1.56) for both PV source circuit and PV output circuit. Once for over irradiance and once for continuous use. But a handout at a recent seminar that I went to totally confused me. Can anyone spell it out very clearly? Thank you. Larry Liesner Wirewiz Westport, CT Phone: 203-644-2404 Fax: 203-557-0556 wire...@gmail.com www.wire-wiz.com ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] Calculation of Maximum Circuit Current
Very good. Thank you Peter. On Fri, Feb 11, 2011 at 2:44 PM, Peter Parrish peter.parr...@calsolareng.com wrote: Short answer: DC/PV side two factors of 1.25; AC side one factor. Reasons: the common factor of 1.25 is due to the treatment of PV systems as continuous sources of power, the second factor of 1.25 is for the cloud effect. It is entirely possible to get more than 1,000 W/m^2 on a PV module if there are large cumulus clouds that don't block the sunlight but act as pretty good reflectors of sunlight. As a result you need to increase Isc (times the number of combined strings if that is the case) by 1.56, and all computed AC currents by 1.25. Same goes for and switches and OCPDs. Then of course you need to compute the ampacity of the wire being used, taking care to apply the temperature correction and conduit fill correction before comparing to the maximum current calculation. - Peter Peter T. Parrish, Ph.D., President California Solar Engineering, Inc. 820 Cynthia Ave., Los Angeles, CA 90065 CA Lic. 854779, NABCEP Cert. 031806-26 peter.parr...@calsolareng.com Ph 323-258-8883, Mobile 323-839-6108, Fax 323-258-8885 -Original Message- From: re-wrenches-boun...@lists.re-wrenches.org [mailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of wire...@gmail.com Sent: Friday, February 11, 2011 11:03 AM To: RE-wrenches@lists.re-wrenches.org Subject: [RE-wrenches] Calculation of Maximum Circuit Current In studying for NABCEP certification I am a little confused about whether you multiply the short circuit current by 1.25 once or twice (1.56) in order to calculate maximum circuit current in determining wire size. Same for overcurrent protection. I have always done it twice (1.56) for both PV source circuit and PV output circuit. Once for over irradiance and once for continuous use. But a handout at a recent seminar that I went to totally confused me. Can anyone spell it out very clearly? Thank you. Larry Liesner Wirewiz Westport, CT Phone: 203-644-2404 Fax: 203-557-0556 wire...@gmail.com www.wire-wiz.com ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org -- Larry Liesner System Design Elektron Solar, LLC 16 Ketchum St. Westport, CT 06880 203-557-3127 (office) 203-644-2404 (cell) 203-549-0977 (fax) wire...@gmail.com ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] PV water pumping
Hi Jeff: I am familiar with that installation you mentioned, which runs all of the buddhist prayer wheels. We have added an additional 100 KW of PV at that site, and at the new temple, Cintimani. Those Kyocera modules that were installed there failed. I found that about 1/3 of the modules were producing 0-10 Voc, vs the 21 Voc specified. As a result, of the low string voltages,the SMA inverters were underperforming significantly or not turning on at all. Kyocera replaced the entire array with new modules, and paid us a fair wage for the trouble. I have spent a couple months of my life working there, which was very peaceful and interesting, to say the least. Each one of those prayer wheels has over a mile of prayers inscribed on a long strip wrapped inside of them. I think I calculated that their were nearly 800 of those wheels, spinning continuously. They say that those wheels send out ~500 million prayers a day! Nick Soleil Project Manager Advanced Alternative Energy Solutions, LLC PO Box 657 Petaluma, CA 94953 Cell: 707-321-2937 Office: 707-789-9537 Fax:707-769-9037 From: Jeff Oldham starpowe...@juno.com To: re-wrenches@lists.re-wrenches.org Sent: Fri, February 11, 2011 8:51:34 AM Subject: Re: [RE-wrenches] PV water pumping Jay is correct about the economics, but sometimes we must live with them as the only way to increase daily water production. However when the tracker fails they will not be making the daily need anymore and it is far more likely to be left dead than even batteries. In developing communities I have often used a village tracker, a manually tracked array that anyone walking by can move to the sun. Along the line of Buddhist Prayer Wheels that are kept spinning by passerby's. As an aside I once did a 40kW grid-tied PV system for a temple to offset the load of the countless motors spinning their Prayer Wheels (not enough people passing to keep them all spinning). From the Solar, Wind and Hydro powered office of Jeff Oldham/Regenerative SOLutions Dermatologists Hate Her Local Mom Reveals $5 Trick to Erase Wrinkles. Shocking Results Exposed Channel9.com ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
