Greetings RE Wrenches;
We've recently completed a family sized off grid system. It was quite
interesting to get all of our plans and references updated to include
all the requirements moved from 690 to the new article 706: Energy
Storage Systems (ESS), and article 710: Stand alone Systems. The issue
we have now encountered with the state electrical inspectors is that
while our feed from the ESS to the house is allowed to be under sized,
they are still requiring the house disconnect be sized according to 225,
which requires a minimum of 100 amps for residential. 225.39(C).
Our points:
1) What is the purpose of having a 100 amp Service disconnect, when the
feeders from the inverter are #6s, and are already protected by a 60 amp
output breaker.
2) Article 706 twice references sizing according to 240: Overcurrent
Protection. It doesn't specifically ever mention 225 or 230.
3) Article 710 (Stand Alone) specifically permits the Power supply to
have less capacity than the calculated load.
Their point is that 710 applies only up to the building disconnect
means, but doesn't actually include the building disconnect. They are
saying the building disconnect still has to be sized according to 225.39(C)
Has anyone dealt with this? Was this the intention of NEC 2017, or is
this another point that could use some rewording?
Thanks,
--
Ray Walters
Remote Solar
303 505-8760
_______________________________________________
List sponsored by Redwood Alliance
List Address: [email protected]
Change listserver email address & settings:
http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org
List-Archive:
http://www.mail-archive.com/[email protected]/maillist.html
List rules & etiquette:
www.re-wrenches.org/etiquette.htm
Check out or update participant bios:
www.members.re-wrenches.org
