Yeah, #10 wire is pretty cheap, especially when purchased in bulk, as are readily available 100A Square D NEMA 3R load centers and breakers. There isn't a great cost savings in terms of material. Sometimes it's just easier to make a single home run. Every job is different. We do it both ways.
Sometimes there isn't enough space near the meter or existing distribution for both a combiner and fusible disconnect or there are obstructions that make it impractical. There are aesthetic concerns (usually overblown by the homeowner or HOA). What we really need is for Square D to start making main distribution equipment with dedicated supply side lugs with OCPD built in. One can dream... Jason On Wed, Apr 30, 2014 at 9:44 AM, jay peltz <j...@asis.com> wrote: > Hi Jason, > > Always good to get a different view on how to do it. > I've always found it easier and cheaper to pull the circuits off the roof > to the AC combiner, so my overcurrent is in a different location > > Jay > Peltz power > > > > > > > On Apr 30, 2014, at 5:08 AM, Jason Szumlanski <ja...@fafcosolar.com> > wrote: > > Each microinverter string needs dedicated overcurrent protection. If > combining strings on the roof for a single run back to the interconnection > point, you need each string to have it's own breaker/fuse. The other option > is to run each string back to the interconnection point separately, but for > a 10kW system you have to do a supply side connection anyway on as typical > 200A service, so combining strings somewhere is necessary, and a single run > from the roof makes sense in many cases. > > > Jason Szumlanski > > Fafco Solar > > > > > > On Tue, Apr 29, 2014 at 6:40 PM, jay peltz <j...@asis.com> wrote: > >> Follow up to Bill's point. >> >> For Micros I've installed a disconnect on the roof, but never a breaker >> or fuse >> Why install a breaker? >> >> jay >> >> peltz power >> >> On Apr 29, 2014, at 9:43 AM, Bill Hoffer wrote: >> >> Dave >> >> I agree, in the case of microinverters, you already have a main PV System >> disconnect at the Load Panel to shut down the system that is readily >> accesible. I would consider the disconnect on the roof as a supplemental >> disconnect for the purposes of maintenance by authorized personal that only >> needs to be accessible. >> >> Bill >> >> >> On Tue, Apr 29, 2014 at 8:44 AM, Dave Click <davecl...@fsec.ucf.edu>wrote: >> >>> I think 240.24(A)(4) allows the installation of the inverter OCPDs in >>> the SolaDeck hidden under a module. >>> >>> *240.24 Location in or on Premises.* >>> *(A) Accessibility.* Overcurrent devices shall be readily accessible >>> and shall be installed so that the center of the grip of the operating >>> handle of the switch or circuit breaker, when in its highest position, is >>> not more than 2.0 m (6 ft 7 in.) above the floor or working platform, >>> unless one of the following applies: >>> ... >>> (4) For overcurrent devices adjacent to utilization equipment that they >>> supply, access shall be permitted to be by portable means. >>> >>> >>> And if panelboards / fused safety switches are allowed to have >>> screwed-down covers over the OCPDs, I'd think that installing a removable >>> module over these OCPDs would meet NEC. I guess an AHJ could argue that >>> this requires TWO covers be removed, unlike a panelboard or a switch. >>> >>> DKC >>> >>> >>> On 2014/4/29, 11:15, Jason Szumlanski wrote: >>> >>> 690.9(D) is not applicable to the original discussion because we were >>> talking about an Inverter output circuit, not a PV Source or Output circuit. >>> >>> 690.34 may apply if you call a SolaDeck with breakers a junction box, >>> but I can see that being a stretch in the mind of many. >>> >>> My and Ray's question about the screws on the SolaDeck cover itself >>> requiring a tool to render it accessible is still an issue if the breakers >>> themselves need to be "readily accessible," but that would also apply to a >>> Midnite MNPV, which also has a cover with a screw. >>> >>> >>> Jason Szumlanski >>> >>>> >>>> On 4/28/2014 5:57 PM, Bill Brooks wrote: >>>> >>>> Read 690.9(D) and 690.34. Not sure where this “hysteria—run for the >>>> border” sentiment is coming from. >>>> >>>> >>>> *690.9(D) Photovoltaic Source and Output Circuits. *Listed PV >>>> >>>> overcurrent devices shall be required to provide overcurrent >>>> >>>> protection in PV source and output circuits. The overcurrent >>>> >>>> devices shall be accessible but shall not be required to >>>> >>>> be readily accessible. >>>> >>>> >>>> *690.34 Access to Boxes. *Junction, pull, and outlet boxes >>>> >>>> located behind modules or panels shall be so installed that >>>> >>>> the wiring contained in them can be rendered accessible >>>> >>>> directly or by displacement of a module(s) or panel(s) secured >>>> >>>> by removable fasteners and connected by a flexible >>>> >>>> wiring system. >>>> >>>> >>>> This is not a change. Please help me understand the concern. >>>> >>>> >>>> Bill Brooks. >>>> >>>> >>>> >>>> *From:* re-wrenches-boun...@lists.re-wrenches.org [ >>>> mailto:re-wrenches-boun...@lists.re-wrenches.org<re-wrenches-boun...@lists.re-wrenches.org>] >>>> *On Behalf Of *Ray Walters >>>> *Sent:* Monday, April 28, 2014 2:23 PM >>>> *To:* RE-wrenches >>>> *Subject:* Re: [RE-wrenches] (no subject) >>>> >>>> >>>> Interesting so does "require a tool" include taking a screw off the >>>> cover plate of the combiner box, too? >>>> What a game changer. I'm going to Mexico for my next project; I'll >>>> actually enjoy even more being the sole AHJ on the project. >>>> >>>> R.Ray Walters >>>> >>>> CTO, Solarray, Inc >>>> >>>> Nabcep Certified PV Installer, >>>> >>>> Licensed Master Electrician >>>> >>>> Solar Design Engineer >>>> >>>> 303 505-8760 >>>> >>>> On 4/28/2014 2:52 PM, Michael Morningstar wrote: >>>> >>>> Readily accessible is now defined in the 2014 NEC. Installing OCPD’s >>>> underneath a module is a major faux paux, and I can’t imagine any AHJ >>>> thinking otherwise. Having to remove a module in order to reset a breaker, >>>> what a drag. >>>> >>>> >>>> "Capable of being reached quickly for operation, renewal or inspection >>>> without requiring those concerned to use a tool, to climb over, remove >>>> obstacle or other.” >>>> >>>> >>>> Michael >>>> >>>> >>>> >>>> >>>> >>>> >>>> On Apr 28, 2014, at 10:29 AM, William Miller <will...@millersolar.com> >>>> wrote: >>>> >>>> >>>> >>>> You call it a solar panel, I call it a glass j-box cover plate. >>>> >>>> William >>>> >>>> Miller Solar >>>> >>>> >>>> On Apr 28, 2014, at 9:21 AM, Jason Szumlanski <ja...@fafcosolar.com> >>>> wrote: >>>> >>>> If that is the interpretation, >>>> I don't see how the breakers are "readily accessible" in a SolaDeck >>>> mounted anywhere, regardless of whether it is under a module. It >>>> requires removal of four screws (using a tool) to access the breakers >>>> inside the enclosure. It's all up to the AHJ. It has not been an issue >>>> locally here. I can see how other jurisdictions may not >>>> concur. >>>> >>>> >
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