William,
I’m shocked and offended (a tiny bit) that you would prejudice yourself to not agree with me ;-). First of all I have been heavily involved in the revising of the language in 690.31(A) to make it clear that we cannot walk up and touch cables operating at 600V. The term guarded is a defined term: Guarded. Covered, shielded, fenced, enclosed, or otherwise protected by means of suitable covers, casings, barriers, rails, screens, mats, or platforms to remove the likelihood of approach or contact by persons or objects to a point of danger. A fence actually does not prevent ready access (unless it does not have a gate), but the term guarded fixes that problem. The guarding means has to be approved by the AHJ, but many methods have been employed including mounting lattice work around the backside of fixed ground-mounted systems. Fences are best used for larger systems (over 50-100kW) whereas other methods—albeit labor intensive—are generally preferred for smaller installations (under 100 kW) No intelligent person would disagree with this proper interpretation of the NEC—including you. Bill. From: RE-wrenches [mailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of William Miller Sent: Friday, September 04, 2015 12:09 PM To: RE-wrenches <re-wrenches@lists.re-wrenches.org> Subject: Re: [RE-wrenches] Guarding against live parts 690.7 (D) Ray: 1. Why no fence? Aesthetics. Also costs may be a wash by the time you mobilize a fencing contractor. 2. I’d apply the same requirements to a fence as one would to an uncovered swimming pool. There are the same consequences if a child ends up in the wrong place. 3. Why bother? We figure the expense will decrease as we figure better design and implementation. Hasn’t yet. We care about safety. I figure we, as an industry, will kill a child by electrocution someday—it is a matter of probability. I hope it won’t be on one of our jobs. We hope, in some small way, we influence the industry to improve. 4. The industry has not developed solutions because there is no demand. There is no demand because AHJs don’t enforce the code. Thanks for the compliment. We have several new designs not yet featured on the web site. Check back next time this comes up. William PS: I am curious what Bill Brooks take on this is, but I don’t think I will agree with his interpretation. W Lic 773985 millersolar.com <http://www.millersolar.com/> 805-438-5600 From: RE-wrenches [mailto:re-wrenches-boun...@lists.re-wrenches.org <mailto:re-wrenches-boun...@lists.re-wrenches.org> ] On Behalf Of Ray Walters Sent: Friday, September 04, 2015 11:37 AM To: RE-wrenches Subject: Re: [RE-wrenches] Guarding against live parts 690.7 (D) WilIiam; checked out your guards on your website, that looks really clean, but also like a lot of work and expense. I'm still so surprised manufacturers are not offering an option like that to their frame systems. My question: how come you didn't just fence the array? Shading issues on the south? If fencing, what height of fence is considered adequate? 4 ft? 6 ft? R.Ray Walters CTO, Solarray, Inc Nabcep Certified PV Installer, Licensed Master Electrician Solar Design Engineer 303 505-8760 On 9/4/2015 9:44 AM, William Miller wrote: Gary: I think the issue of PV wiring behind module that are readily accessible is addressed in (2014) 690.31: Where PV source and output circuits operating at maximum system voltages greater than 30 volts are installed in readily accessible locations, circuit conductors shall be guarded or installed in a raceway. I am not sure what application the original poster had in mind, but this is the question I think you are asking. The interpretation to 690.31 seems clear to me: No one should be able to touch the conductors without resorting to a ladder, opening a locked gate or removing a protective panel. Readily accessible is defined thusly: Capable of being reached quickly for operation, renewal, or inspections without requiring those to whom ready access is requisite to actions such as to use tools, to climb over or remove obstacles, or to resort to portable ladders, and so forth. Implementing this is harder than it might seem. Lacking a fence, the installer must either use the flimsy solar-scrim product or fabricate his or her own shielding. We have put a fair amount of effort towards this. See link <http://www.millersolar.com/MillerSolar/practices/PV_wiring/Wire_shielding/_Wire%20Shielding_history.html> . William Lic 773985 millersolar.com <http://www.millersolar.com/> 805-438-5600 From: RE-wrenches [mailto:re-wrenches-boun...@lists.re-wrenches.org <mailto:re-wrenches-boun...@lists.re-wrenches.org> ] On Behalf Of gary easton Sent: Friday, September 04, 2015 2:22 AM To: RE-wrenches Subject: Re: [RE-wrenches] Guarding against live parts 690.7 (D) Bill Are you saying there is no requirement to shield wires on a ground array? On Friday, September 4, 2015, <billbroo...@sbcglobal.net <mailto:billbroo...@sbcglobal.net> > wrote: Craig, This one is easy to misinterpret. You missed the words “live parts”. This has been removed from the 2017 NEC because it is actually referring to load circuits being fed directly by a PV system on the dc side. All references to loads and batteries are being removed from 690. This is a complete non-issue. Bill. From: RE-wrenches [mailto:re-wrenches-boun...@lists.re-wrenches.org <javascript:_e(%7B%7D,'cvml','re-wrenches-boun...@lists.re-wrenches.org');> ] On Behalf Of Craig Gerald Buttke Sent: Thursday, September 03, 2015 11:44 AM To: re-wrenches@lists.re-wrenches.org <javascript:_e(%7B%7D,'cvml','re-wrenches@lists.re-wrenches.org');> Subject: [RE-wrenches] Guarding against live parts 690.7 (D) How is everyone handling 690.7 (D) Circuits over 150 Volts to Ground. In one- and two- family dwellings, live parts in photovoltaic source circuits and photovoltaic output circuits over 150 volts to ground shall not be accessible to other than qualified persons while energized. If you have a commercial (non one or two-family dwelling) are you screening your ground mount arrays to keep people from touching live conductors PV wires)? Thanks for your thoughts -- Yours in Solardarity, Craig Gerald Buttke M:(715) 630-1227 O:(715) 630-6451 F:(715) 952-4501 North Wind Renewable Energy, LLC 1626C W Pearl Street Stevens Point, WI 54481 www.northwindre.com <http://www.northwindre.com> NABCEP Certified PV Installation Professional™ NABCEP Certified PV Technical Sales Professional™ State of WI: Master Electrician _____ <https://www.avast.com/antivirus> This email has been checked for viruses by Avast antivirus software. www.avast.com <https://www.avast.com/antivirus> -- Sent from Gmail Mobile _______________________________________________ List sponsored by Redwood Alliance List Address: RE-wrenches@lists.re-wrenches.org <mailto: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 <http://www.re-wrenches.org/etiquette.htm> Check out or update participant bios: www.members.re-wrenches.org <http://www.members.re-wrenches.org> --- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus
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