William, Not sure I understand how buried PV runs protected by touchsafe fuses in combiner boxes at the array and GFCI protection at the inverters constitute a fire hazard. That's not saying I disagree with your disconnect here. I don't. If it was a 1kW system, would you still install one? I would not.
Would not a deeper trench with properly located burial tape have been a good call? If the array was installed and visible, maybe the excavation operator would have thought to ask about underground utilities. They should have anyway. Would not common sense imply the operator would drop a bucket of fill on any sign of arcing. Would they know to look for a disconnect at the array in any case? Common sense can be slippery. Dick Solarwind Electric --- You wrote: Friends: I am embarking on a 10 Kw ground mount grid-tie installation. The client prepared for this installation some time ago by stubbing a PVC conduit underground towards the future location of the PV array. Prior to beginning this job, an excavation contractor intercepted the empty conduit with a backhoe. No harm was done because this conduit was empty. Had this conduit been filled with PV feeders, it would have been very necessary to be able to disconnect the PV arrays, both for safety and to prevent a brush fire in our very dry climate. The inverters will be located in a pump house about 130 feet from the PV arrays. I would not normally put disconnects at the array and they are not required. This scenario, however, has caused me to reconsider. The design now calls for a disconnect at each row of modules. I feel that it would not be prudent to delete this important safety item. I wish there were a better selection of compact, low profile disconnects suitable for a roof-top installation. I have put external handle disconnects on roof but they look terrible. I may specify touch-safe fuse holders inside of a Sola Deck for future comp roof jobs. I am not sure what we will do with tile roofs. It seems to me that every source of power should have a means of disconnection as close to the source as possible. This is just common sense. William Miller Please note new e-mail address and domain: William Miller Miller Solar Voice :805-438-5600 email: will...@millersolar.com http://millersolar.com License No. C-10-773985 _______________________________________________ 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 --- end of quote --- _______________________________________________ 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
