Yeah, normally it would have been our practice to use a j-box and bring down three strings. In this case it made more sense to combine strings on the roof and just bring down a single circuit in a single conduit. Long story... long wire run... probably bad planning in hindsight.
The MNPV6-AC is a new product with a disconnect on the front exterior and up to six breakers on a DIN rail that you can combine with bus bars that they supply. It is specifically for combining AC strings. I think it's rated for 120A per pole. I'm impressed with the units. It makes a great residential Enphase string combiner. List price is $239.00 and it's on their site as the last item here: http://www.midnitesolar.com/products.php?menuItem=products&productCat_ID=34&productCatName=PV%20Disconnecting%20Combiners%20-Not%20Birdhouse%20Compatible You are right - jurisdictions around here do not require disconnects on the roof. The AC connectors on the inverters suffice. We normally just do a j-box and transition to THWN. We've been using TC-ER to extend the trunk lines and just use one j-box with all circuits running down a single conduit to whatever combiner we need or to the load center for smaller systems. No utility discos <10kW here. Yay! *Jason Szumlanski** * *Fafco Solar* * * On Fri, Feb 8, 2013 at 11:11 AM, jay peltz <j...@asis.com> wrote: > Hi jason, > > 3 questions, > I can't find the MNPV-AC in midnites price list, is this something custom > or just new? > And > if you don't need breakers why not just do a junction box on the roof. > and > the inspectors I've had have requested a disconnecting means on the roof > or visible from the roof. So I've done the enphase suggested switches on > the roof, but no overcurrent. It doesn't appear that is a requirement from > your inspector? > > > jay > > peltz power > > > On Feb 8, 2013, at 7:27 AM, Jason Szumlanski wrote: > > Oh, yes - that is a great application for the MNPV-AC. I didn't mean to > imply there isn't a good use for them. In this particular instance the > three MVPV-AC's are really subcombiners that get all get tied together in > another subpanel at ground level. They really were not necessary, but made > it more convenient and cost effective. > > It's just interesting how Midnite advertises that they can be mounted as > flat as a 3:12 pitch. What application would allow this mounting angle > where it is still readily accessible? The spec/advertising seems to imply > that these can be roof mounted in an AC string combining application. > > The Soladeck combiner with fuses would appear to be non-code compliant in > any situation. I would love for someone to refute that in a convincing way > given the access requirements in 240.24(A). > > *Jason Szumlanski* > *Fafco Solar* > > > On Thu, Feb 7, 2013 at 7:31 PM, jay peltz <j...@asis.com> wrote: > >> Hi Jason, >> >> Is it possible to install them on the side of a building? >> And Dan's suggestion for the remote midnite might be perfect. >> >> jay >> >> >> On Feb 7, 2013, at 3:55 PM, Jason Szumlanski wrote: >> >> Jay, >> >> I assume you mean pitched roofs, or not readily accessible flat roofs. >> This particular project happens to be a flat commercial roof, but with no >> permanent ladder or hatch. I really didn't have to use the MNPV6-AC's, but >> it made sense in this case (excluding the access issue). >> >> Looks like my options are to remove the combiners or install a permanent >> access. Neither are fun options. Live and learn... >> >> *Jason Szumlanski** * >> *Fafco Solar* >> >> > >
_______________________________________________ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options & settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules & etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
