[RE-wrenches] Two NEC questions
Dear fellow wrenches, Does anyone have suggestions for the 'best' way to keep up with product availability for meeting 690.11 on DC AFCI? I understand that when this code section was written there was no available device, and know that at least several companies are working on devices. How will I know (before the AHJ knows :-) that residential-scale products are available for purchase, and at what point would you say now should be required over every other option? Second question: I have an inspector insisting that the solar PV system is the same as a utility service, and is requiring all of the required service code references to apply. Anybody have a concise reference that might convince him otherwise? This same inspector has decided that the electrical permit will have adders for each inverter as service equipment, and each module as an electrical device. It would sure be nice if there was more consistency...we're still in the early adopter phase here in Minnesota. Thanks in advance for your input. Keep Shining! Rebecca Lundberg NABCEP Certified Solar PV Installer ® Owner/CEO, Powerfully Green rebecca.lundb...@powerfullygreen.com 763-438-1976 ___ 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] Two NEC questions
RE Question #2: Article 100 defines a service as: Service. The conductors and equipment for delivering electric energy from the serving utility to the wiring system of the premises served. (emphasis added) PV system wiring simply does not fit that definition. The PV system is not part of the serving utility. And inverters are not service equipment. You need to refers them to this definition in Article 705.2 (added in NEC 2011): Power Production Equipment. The generating source, and all distribution equipment associated with it, that generates electricity from a source other than a utility supplied service. (emphasis added) FWIW: Mike Holt has written for SP about the Code requirements for interconnecting PV systems, as well as some additional recommendations for making supply side connections: http://solarprofessional.com/article/?file=SP5_1_pg14_QAsearch= RE Question #1: I had a local inspector ask me about this in late-August there were relatively few listed products at that time: SMA America has dc AFCI in their standard SunnyBoy US-series inverters (SB 3000-US, SB 3800-US, SB 4000-US, SB 5000-US, SB 6000-US, SB7000-US, SB 8000-US): http://www.sma-america.com/en_US/news-information/current-news/news/news/1487.html Microinverter systems (Enphase, Enecsys, etc.) typically do not operate above 80 Vdc and are therefore exempt from 690.11 AC module systems (powered by SolarBridge, Exeltech, etc.) typically do not operate above 80 Vdc and are therefore exempt from 690.11 SolarBOS reportedly has a dc AFDI and GFI combiner box: http://www.solarbos.com/news/solarbos-puts-out-the-fire-in-pv-systems (However, I don't see this product on their website under their regular lists of products.) While module-level dc-to-dc converters—like those from SolarEdge and Tigo Energy—presumably have the ability to provide dc AFCI capabilities, last I checked it didn't look like any of them were formally listed to do so. I suspect that most manufacturers are trying to avoid spending additional money on testing until the market requires this. Have any wrenches here actually had an inspector required dc AFCI? Also, is the dc AFCI test standard actually finalized and adopted at this point or are companies testing to a draft standard? David Brearley, Senior Technical Editor SolarPro magazine NABCEP Certified PV Installer ™ david.brear...@solarprofessional.com Direct: 541.261.6545 On Oct 13, 2012, at 10:12 AM, Rebecca Lundberg wrote: Dear fellow wrenches, Does anyone have suggestions for the 'best' way to keep up with product availability for meeting 690.11 on DC AFCI? I understand that when this code section was written there was no available device, and know that at least several companies are working on devices. How will I know (before the AHJ knows :-) that residential-scale products are available for purchase, and at what point would you say now should be required over every other option? Second question: I have an inspector insisting that the solar PV system is the same as a utility service, and is requiring all of the required service code references to apply. Anybody have a concise reference that might convince him otherwise? This same inspector has decided that the electrical permit will have adders for each inverter as service equipment, and each module as an electrical device. It would sure be nice if there was more consistency...we're still in the early adopter phase here in Minnesota. Thanks in advance for your input. Keep Shining! Rebecca Lundberg NABCEP Certified Solar PV Installer ® Owner/CEO, Powerfully Green rebecca.lundb...@powerfullygreen.com 763-438-1976 ___ 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] Two NEC questions
You can see what products UL has listed (though not other NRTLs) at: www.ul.com Near the bottom of the page on the right hand side click on: Online Certifications Directory Into the UL Category Code box enter: QIDC (for inverters with integrated dc arc-fault) or QIDC2 (for dc arc-fault components) And hit search. Only SMA and Eaton presently. I imagine that as more products become available more press releases will follow as well. You can also download a copy of the UL Whitebook to cross check other standards with the NEC. Brian Mehalic NABCEP Certified Solar PV Installer™ R031508-59 IREC ISPQ Certified Affiliated Instructor/PV US-0132 PV Curriculum Developer and Instructor Solar Energy International http://www.solarenergy.org On Sat, Oct 13, 2012 at 11:12 AM, Rebecca Lundberg rebecca.lundb...@powerfullygreen.com wrote: Dear fellow wrenches, Does anyone have suggestions for the 'best' way to keep up with product availability for meeting 690.11 on DC AFCI? I understand that when this code section was written there was no available device, and know that at least several companies are working on devices. How will I know (before the AHJ knows :-) that residential-scale products are available for purchase, and at what point would you say now should be required over every other option? Second question: I have an inspector insisting that the solar PV system is the same as a utility service, and is requiring all of the required service code references to apply. Anybody have a concise reference that might convince him otherwise? This same inspector has decided that the electrical permit will have adders for each inverter as service equipment, and each module as an electrical device. It would sure be nice if there was more consistency...we're still in the early adopter phase here in Minnesota. Thanks in advance for your input. Keep Shining! Rebecca Lundberg NABCEP Certified Solar PV Installer ® Owner/CEO, Powerfully Green rebecca.lundb...@powerfullygreen.com 763-438-1976 ___ 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] Two NEC questions
Rebecca, First off, nice install on the four SiE pole mounts! Second, as long as we are talking strictly grid-tied systems, not AC coupled or battery backup, it seems like Solar should be viewed more like an appliance. It supplements the service at your house. That being said, you've got a tough battle ahead. Hopefully someone else on the list has a great way of calming this inspector down with some good old code lullibies. Good luck! Sometimes it feels like the Solar 'cops', I mean inspectors, are trying to justify their jobs. Alex Cozine NABCEP Certified Solar PV Installer Journeyman Electrician EL01 www.brotherselectricsolar.com On Oct 13, 2012 8:13 AM, Rebecca Lundberg rebecca.lundb...@powerfullygreen.com wrote: Dear fellow wrenches, Does anyone have suggestions for the 'best' way to keep up with product availability for meeting 690.11 on DC AFCI? I understand that when this code section was written there was no available device, and know that at least several companies are working on devices. How will I know (before the AHJ knows :-) that residential-scale products are available for purchase, and at what point would you say now should be required over every other option? Second question: I have an inspector insisting that the solar PV system is the same as a utility service, and is requiring all of the required service code references to apply. Anybody have a concise reference that might convince him otherwise? This same inspector has decided that the electrical permit will have adders for each inverter as service equipment, and each module as an electrical device. It would sure be nice if there was more consistency...we're still in the early adopter phase here in Minnesota. Thanks in advance for your input. Keep Shining! Rebecca Lundberg NABCEP Certified Solar PV Installer ® Owner/CEO, Powerfully Green rebecca.lundb...@powerfullygreen.com 763-438-1976 ___ 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] Two NEC questions
Midnite Solar has some DC arc fault equipment both built into their charge controllers (for battery based systems) and their Combiner boxes. The nice thing about having AFCI at the combiner is that it actually protects the wiring from the array to the inverter, so if an arc is occurring in say the attic, it will interrupt the electricity at its source, not at the load. Ray Walters On 10/13/2012 9:12 AM, Rebecca Lundberg wrote: Dear fellow wrenches, Does anyone have suggestions for the 'best' way to keep up with product availability for meeting 690.11 on DC AFCI? I understand that when this code section was written there was no available device, and know that at least several companies are working on devices. How will I know (before the AHJ knows :-) that residential-scale products are available for purchase, and at what point would you say now should be required over every other option? Second question: I have an inspector insisting that the solar PV system is the same as a utility service, and is requiring all of the required service code references to apply. Anybody have a concise reference that might convince him otherwise? This same inspector has decided that the electrical permit will have adders for each inverter as service equipment, and each module as an electrical device. It would sure be nice if there was more consistency...we're still in the early adopter phase here in Minnesota. Thanks in advance for your input. Keep Shining! Rebecca Lundberg NABCEP Certified Solar PV Installer ® Owner/CEO, Powerfully Green rebecca.lundb...@powerfullygreen.com 763-438-1976 ___ 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-wrenches] Off-grid 1nverter replacement for 3 HP
I have an off-grid client who is having trouble with his aging Xantrex SW4024 inverter and is considering an upgrade. I need some advice. One of his problems with his present system is that he can't run his 3 HP 240VAC table saw on the 4024. He'd be content to run his generator for any long sessions of sawing, but he'd like the capability to do a cut or two without firing it up. I was thinking about stacking a couple of Outbacks. I'd like to know people's real-world experiences with the relationship between motor HP, rated inverter watts, and surge watts. How much wattage does he need to actually do the job? That is, without flailing the inverter(s) into a shortened life span. Also, how do Outbacks compare with Magnums or whatever? I have been using Outbacks for a while with good results, but I have been hearing murmurs and grumbling since they were bought out. I haven't used Xantrex/Schneider for a while and I have no experience with Magnums. I notice that the Magnums offer split phase 240. I should note that he has his inverter setup in his wood shop. I am theorizing that some of his inverter trouble could be from a tree's worth of sawdust in the case. He presently has a 24V system, but he is considering a battery replacement, which would be an opportunity to switch to 48V if necessary. The sawdust issue makes me lean towards the sealed Outbacks, but he does have a partially finished box for the inverter with filters and a fan. Opinions? Many thanks. Hilton -- Hilton Dier III Renewable Energy Design Partner, Solar Gain LLC 453 East Hill Rd. Middlesex, VT 05602 Tel: 802-223-6652 ___ 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] Off-grid 1nverter replacement for 3 HP
HI Hilton, Before you go anywhere you need to know what the draw on this motor is. I've seen 3 hp motors not be able to start on a 15kw genny. Why? Just horrible motors thats all. jay peltz power On Oct 13, 2012, at 11:16 AM, Hilton Dier III wrote: I have an off-grid client who is having trouble with his aging Xantrex SW4024 inverter and is considering an upgrade. I need some advice. One of his problems with his present system is that he can't run his 3 HP 240VAC table saw on the 4024. He'd be content to run his generator for any long sessions of sawing, but he'd like the capability to do a cut or two without firing it up. I was thinking about stacking a couple of Outbacks. I'd like to know people's real-world experiences with the relationship between motor HP, rated inverter watts, and surge watts. How much wattage does he need to actually do the job? That is, without flailing the inverter(s) into a shortened life span. Also, how do Outbacks compare with Magnums or whatever? I have been using Outbacks for a while with good results, but I have been hearing murmurs and grumbling since they were bought out. I haven't used Xantrex/Schneider for a while and I have no experience with Magnums. I notice that the Magnums offer split phase 240. I should note that he has his inverter setup in his wood shop. I am theorizing that some of his inverter trouble could be from a tree's worth of sawdust in the case. He presently has a 24V system, but he is considering a battery replacement, which would be an opportunity to switch to 48V if necessary. The sawdust issue makes me lean towards the sealed Outbacks, but he does have a partially finished box for the inverter with filters and a fan. Opinions? Many thanks. Hilton -- Hilton Dier III Renewable Energy Design Partner, Solar Gain LLC 453 East Hill Rd. Middlesex, VT 05602 Tel: 802-223-6652 ___ 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] Off-grid 1nverter replacement for 3 HP
I have had inverters ruined by drywall dust, it literally filled them within a couple years as the owner worked on his house. Next thing I am getting a call that it would not work.. I doubt that sawdust would be any different. Later, Bob Ellison From: re-wrenches-boun...@lists.re-wrenches.org [mailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of jay peltz Sent: Saturday, October 13, 2012 5:28 PM To: RE-wrenches Subject: Re: [RE-wrenches] Off-grid 1nverter replacement for 3 HP HI Hilton, Before you go anywhere you need to know what the draw on this motor is. I've seen 3 hp motors not be able to start on a 15kw genny. Why? Just horrible motors thats all. jay peltz power On Oct 13, 2012, at 11:16 AM, Hilton Dier III wrote: I have an off-grid client who is having trouble with his aging Xantrex SW4024 inverter and is considering an upgrade. I need some advice. One of his problems with his present system is that he can't run his 3 HP 240VAC table saw on the 4024. He'd be content to run his generator for any long sessions of sawing, but he'd like the capability to do a cut or two without firing it up. I was thinking about stacking a couple of Outbacks. I'd like to know people's real-world experiences with the relationship between motor HP, rated inverter watts, and surge watts. How much wattage does he need to actually do the job? That is, without flailing the inverter(s) into a shortened life span. Also, how do Outbacks compare with Magnums or whatever? I have been using Outbacks for a while with good results, but I have been hearing murmurs and grumbling since they were bought out. I haven't used Xantrex/Schneider for a while and I have no experience with Magnums. I notice that the Magnums offer split phase 240. I should note that he has his inverter setup in his wood shop. I am theorizing that some of his inverter trouble could be from a tree's worth of sawdust in the case. He presently has a 24V system, but he is considering a battery replacement, which would be an opportunity to switch to 48V if necessary. The sawdust issue makes me lean towards the sealed Outbacks, but he does have a partially finished box for the inverter with filters and a fan. Opinions? Many thanks. Hilton -- Hilton Dier III Renewable Energy Design Partner, Solar Gain LLC 453 East Hill Rd. Middlesex, VT 05602 Tel: 802-223-6652 ___ 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] AC (only) Diversion
Hi Nathan and Wrenches. Sharkey asked me to post this for him: In response to Nathan Stumpff, I designed and use a microprocessor-based dump load to keep my RE power off the grid: http://www.mrsharkey.com/solar-power-diversion-load-controller (see links at the top of this page for previous editions covering development of the design). Also, have him take a look at http://openenergymonitor.org/emon/node/841 for a phase-control system that uses a triac device. Tell him to beware, if he is connected through a modern digital meter, not only will it not credit him for power fed back to the grid, he'll be charged the retail rate for every KwH that he places on the utilities lines!!! Nathan Stumpff wrote at 12:36 PM 10/12/2012: Wrenches, We are working on the design for a system where we will be using grid-tied wind and solar but will not be able to net-meter the project (we can interconnect but the meter only runs one way.) Anything we use on site is worth 100%, any production that goes back to the grid is lost forever to the customer. What we would like to do is monitor all solar and wind production, monitor all usage, and then be able to dump every watt-hour of over production as heat, there is plenty of (thermal) storage capacity. If this were a battery based system I know how I would approach this and what equipment I would spec, but so far I am having a hard time coming up with a solution. Anyone have any suggestions for products or strategies in this case? Something like an eGauge with programmable PWM relay outputs? Any thoughts or suggestions are most appreciated, -Nathan ___ 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
