Thanks for the correction on that sedona fire Bill; I had only seen the incorrect fire dept report. I wish there was a clearinghouse for information on RE incidents and close calls as they are all teachable moments for both RE professionals and firefighters.
I ditto the need for more NEC guidance on battery banks. In my firefighting career, I've been at about a dozen structure fires involving RE equipment. Only 4 were actually caused by the RE equipment. *All* of those originated in or near the battery bank. 1 internal battery short circuit, 1 mouse chew inside battery box, and 2 bad connection when charging with a generator. I'd like to get involved, Bill....I have lots to say about wooden battery boxes, parallel fusing, signage, and more. What are the first steps for getting involved? Dan Fink, Executive Director; Otherpower Buckville Energy Consulting Buckville Publications LLC NABCEP / IREC accredited Continuing Education Providers 970.672.4342 On Thu, Jan 23, 2014 at 12:23 PM, Bill Brooks <billbroo...@yahoo.com> wrote: > Jeffrey and Ray, > > > > Batteries can off-gas hydrogen-sulfide gas when under heavy charge or > overcharge. It is the nasty rotten egg smelling gas. Definitely not to be > inhaled since when it hits your lungs it turns back into sulfuric acid. > > > > To address Ray’s point, the new 690.12 regulation that has been getting a > lot of air time on this list does, in fact, address battery circuits for PV > systems. Any circuit that is part of a PV system inside a building within > 5’ must be controlled to 30V, 240VA within 10 seconds. This includes all > the ac output conductors from a backup PV inverter and the battery inverter > input circuit as well. This provision matches the new requirement for > battery systems in 690.71(H) that requires “A disconnecting means and > overcurrent protection shall be provided at the energy storage device end > of the circuit. Fused disconnecting means or circuit breakers shall be > permitted to be used.” Ideally we try to keep our battery conductors to 5’ > or less and that means that no additional disconnecting means would be > necessary according to the new 690.71(H). If we have to go longer than 5’ > and the conductors are inside the building, a rapid shutdown capability > would need to be on that circuit and it would need to have a disconnecting > means and overcurrent protection. The best way to meet this requirement > would probably be to have a shunt-trip breaker, similar to what Midnite > Solar provides with their birdhouse setup. > > > > There are definitely much more discussion going on in the NEC about energy > storage now than ever before. This next code cycle will be very busy on the > subject. It is likely that article 480 will soon be turned into “Energy > Storage” or a new article in Chapter 6 or 7 will cover “Energy Storage > Systems.” It was proposed last cycle and failed, but this time there is > much more interest in the subject. The solar industry needs to be involved, > so it sounds like this is your year for both of you to get involved. > > > > Bill. > > >
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