Ryan, 690.11 refers to any system that is building mounted--usually roof mounted, but an awning would apply. It is not intended to deal with ground-mounted systems unless the dc conductors penetrated a building. The intension is that any PV system associated with a building where people are located would have this extra safety.
Bill. -----Original Message----- From: re-wrenches-boun...@lists.re-wrenches.org [mailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of Ryan J LeBlanc Sent: Wednesday, March 02, 2011 11:10 PM To: re-wrenches@lists.re-wrenches.org Subject: [RE-wrenches] NEC 690.11 - Arc Fault Protection Provision Questions ? Wrenches, NEC 2011, 690.11 says, "PV Systems with DC source Circuits, DC output Circuits, or both, on or penetrating a building...at over 80V... Shall be protected by a listed (DC) arc fault circuit interrupter, PV type, or other system components listed to provide equivalent protection." and then it goes on to say what the arc fault should do. My questions are: 1) What does "on" mean? On the roof? attached to the wall? Say the array is in a field, with combiner boxes having PV output circuits run underground and stubbed up into the bottom of a DC disconnect mounted to the side of a house. The conduit is strapped to the side of the house on it way up to the bottom of the disconnect switch. Is this "on" the building? 2) What is a "building"? Is it a dwelling, small and large commercial buildings? How about an enclosed MW in a box solution in the middle of a MW power plant, is that a building? I like for example that in the 600V max limitation that it specifies 1 or 2 family dwellings, leaving small & large commercial buildings opportunity to have 1000V systems. Any clarification from Bill Brooks, Matt Lafferty, David Brearly, or the host of other awesome PV Guru's on the list is extremely appreciated. ~Ryan L _______________________________________________ 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
