Drake, The language in 690.12 is the compromise solution that was reached to ensure continued industry stability. The alternative to the combiner-level shutdown was module-level shutdown. It took a consolidated industry effort to push the module-level requirements out one more Code cycle—for the exact reasons that you touch on below.
Not sure if this link has been published on the Wrenches list or not, but it provides some background on the topic: http://www.youtube.com/watch?v=sUXShMZJorQ David Brearley Senior Technical Editor, SolarPro magazine NABCEP Certified PV Installation Professional david.brear...@solarprofessional.com Direct: 541.261.6545 On Jan 21, 2014, at 1:12 PM, re-wrenches-requ...@lists.re-wrenches.org wrote: > From: Drake <drake.chamber...@redwoodalliance.org> > Subject: Re: [RE-wrenches] NEC 2014 690.12 Rapid Shutdown > Date: January 21, 2014 11:36:15 AM CST > To: RE-wrenches <re-wrenches@lists.re-wrenches.org> > Reply-To: RE-wrenches <re-wrenches@lists.re-wrenches.org> > > > > Bill, > > It is good to see that energized conductors are going to be disconnected near > the arrays. I've been an advocate of disconnecting these conductors by ground > fault sensing equipment since ground fault detection was first implemented in > the code. If contactors are to be installed on roofs, it likely won't be long > before both ground faults and arc faults are automatically cleared. > > When the requirement for AC arc fault branch circuit protection was first put > in the NEC, it was postdated to allow time for the electrical industry to > adapt. This new remote disconnecting requirement does not provide any lead > time. > > As the 2014 NEC is adopted in various jurisdictions, inspectors may feel that > it is necessary to disallow systems without the newly required disconnect > feature. This may result in serious problems for solar companies and > customers, as well as manufacturers. > > The protection of firefighters is essential. The implementation of renewables > is essential also. Insurance claims for weather related, global > warming-triggered climatic disasters are rising exponentially. Extreme > weather related events result in major loss of life and billions of dollars > in property damage. Atmospheric CO2 levels continue to climb from the burning > of fossil fuels. This is a crisis of global proportions. > > My request for code writers is to please take into account the effect that > inserting new rules into the NEC may have on the stability of renewable > energy, and implement new requirements in a way that will allow for a smooth > interface. > > Thank you, > > Drake > > Drake Chamberlin > Athens Electric LLC > OH License 44810 > CO License 3773 > NABCEP Certified Solar PV > 740-448-7328 > http://athens-electric.com/
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