Mark, The fact is you can't legally walk up and touch NM cable anymore. Whenever your house was built, that may have been code compliant, but not since the early 1990s has that been allowed. You may think a wooden lattice work is insufficient protection, but the code disagrees with you as a minimum standard. You can build all the chain link fences you want around your PV systems. Not me. It is a waste of money. The code is addressing the issue of "readily accessible." Darwin awards are plentiful for people who want to get themselves into trouble. We just have to make it a little more difficult for unsuspecting kids using the underside of a PV array for a play fort. You obviously haven't been to one of my code trainings in a long time. Maybe it's time for a refresher.
The 30V limit has to do with the voltage at which serious shock can occur in wet environments. Most people are familiar with the 50V limit by OSHA, but that is for dry environments. In the UL standards for shock hazard, the voltage limit is 30V. Now you know. Bill. -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Mark Frye Sent: Thursday, October 21, 2010 3:37 PM To: 'RE-wrenches' Subject: Re: [RE-wrenches] Ground Mount Screening You know, I can go down into my unfinished basement, through an unlocked full height door. The wiring in this space is fully Code compliant. And yet, I can walk over and put my bare hand right onto a piece NM cable that has 200A of 240 VAC running on it. But God forbid I should be able to walk over to a PV array and put my hand on a piece of double insulated PV wire with 10A of 30VDC running on it. I don't get it. Mark Frye Berkeley Solar Electric Systems 303 Redbud Way Nevada City, CA 95959 (530) 401-8024 www.berkeleysolar.com -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Jason Szumlanski Sent: Thursday, October 21, 2010 3:26 PM To: RE-wrenches Subject: Re: [RE-wrenches] Ground Mount Screening Maybe they should require that extension cords be in conduit. :) where do you draw the line? If lattice is good enough, is fiberglass screen okay? How about bird netting or orange construction fence? Seriously though, we have never been required to use a lattice or fenced enclosure for a ground rack around here to pass inspection. It would be nice if a rack manufacturer came up with a slick and cost effective (cheap) method to cover the back of the panels /racks without losing air flow and meeting code requirements. I would install that regardless of lax local interpretation. Jason Szumlanski Fafco Solar _______________________________________________ List sponsored by Home Power magazine List Address: [email protected] 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: [email protected] 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
