[RE-wrenches] RE-wrenches Digest, Vol 7, Issue 29

[Dan Fink]

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 <billbrooks7 at 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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