I thought this idea (attached) was a simple solution for array and battery rapid shutdown using a Classic controller and solenoids. The PV solenoids are 350 amp continuous @ 700 Vdc, and 400A @ 48 volts for the battery. Cost is about $120 each.
Midnite told me than plan to implement the arc fault relay control. A simple SPST switch in series with the 12 volt Aux output will allow shutdown. Add a fire alarm output relay for auto-shutdown in case of fire. Seems like a simple, cost effective way to me. Any comments Ray, Pete, Bill? Larry Crutcher Starlight Solar Power Systems On Mar 15, 2016, at 12:48 PM, Patrick Shortell <pshorte...@gmail.com> wrote: Dear List, Maybe it's an over simplistic opinion, but shouldnt all sources be disconnected rapidly in an emergency situation. We can always do better than what the code requires. I get frustrated when people go to the book, (and try to hide behind the text). instead of thinking through real life scenarios. There are simple ways to work around these issues. I find when something is questionable, Ill call the AHJ and get his approval First. What would I do in my own house? What if someone thought all the power was off when they dragged a hoseline into my basement. My two cents Pat On Tue, Mar 15, 2016 at 1:10 PM, <billbroo...@sbcglobal.net <mailto:billbroo...@sbcglobal.net>> wrote: Ray, I guess I have to step in after that acknowledgement. PV system circuit is a self-defined term and therefore cannot be defined unless you are going to develop a meaning that is different from the self-definition. It means ANY circuit in a PV system. This includes battery and stand-alone circuits in the 2014 NEC. The language of the 2014 NEC was a compromise between the fire service and the PV industry. Originally, the language required essentially module-level shutdown. I raised the concern with the PV industry to get them involved since most were not paying attention at the time. This language was developed and intended to cover all circuits in a PV system. In the 2014 NEC, batteries are part of a PV system and therefore fall under this requirement. In the 2017 NEC, we were very careful to carve out all batteries and loads, that were previously part of PV systems, and place them in their own articles. Don't shoot the messenger on this one and don't think for a minute that I alone made this requirement or am alone in interpreting it in this way. I did author this compromise with other representatives of the PV industry so I think I know what the intent was. It is understandably difficult for battery systems and I would try to keep battery circuits as short as possible. The 5-feet was intended to match the requirement of 690.71(H)--which is further evidence of the intent of the 2014 NEC. The 2017 NEC removes batteries from the requirement, but they still cannot backfeed the PV array. Energy storage systems (Article 706) will have their own requirements in time--that is guaranteed. Bill. -----Original Message----- 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: Tuesday, March 15, 2016 9:02 AM To: RE-wrenches <re-wrenches@lists.re-wrenches.org <mailto:re-wrenches@lists.re-wrenches.org>> Subject: [RE-wrenches] Rapid Shutdown Greetings Esteemed Wrenches: I've just heard back from our inspector here in Colorado, and we are still being required to disconnect the batteries under 690.12. No where in 690.12 are batteries mentioned, nor in the appropriate 690.71 section that deals with batteries. The entire reasoning behind this is based on a single article written by a single person: Bill Brooks. I have contacted both Outback and Magnum on this issue, and their engineers are unaware that rapid shutdown applies. My interpretation is that I could install an inverter and battery system that was charged from a generator, and we would not need any rapid shutdown at all. But according to Bill, as soon as I put a single solar module into the system, suddenly the entire system becomes PV? The problem lies with the term 'PV System circuit' used in 690.12. 690.2 Defines 'PV Output circuit', and 'PV source circuit', but there is no 'PV system circuit' defined. 690.12 therefore uses an undefined term. Our design uses 2 inverters, so if we used Midnite's E panel with their remote trip breakers, the 2nd inverter would be more than 5 ft from the batteries. If we used Magnum or Outback DC disconnects (that would comply with the 5 ft rule specified in 690.71) they don't offer remote trip. We have a Midnite Rapid disconnect Combiner on the roof with the Birdhouse, so we are complying with 690.12, it should not be applied to batteries though. Thanks, -- R.Ray Walters CTO, Solarray, Inc Nabcep Certified PV Installer, Licensed Master Electrician Solar Design Engineer 303 505-8760
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