Thanks Brian, That's kind of what I was thinking. Regarding the DC disconnect, would that need to be grouped with the other system? Also from a code perspective, even those there are "two systems" is it still considered one array or an array of arrays?
Best, -N On Fri, Mar 14, 2014 at 5:56 PM, Brian Teitelbaum <[email protected]>wrote: > Ah...OK > > > > Looks like you have two options: > > > > Locate the shop's inverter on the house, and run 240 VAC the 100 feet to > the shop, where it will connect at the shop's service entrance. > > > > Or, locate the inverter at the shop, and run the PV array DC the extra 100 > foot distance. > > > > Which is better? Electrically, I don't think that it really matters much. > > > > With the inverter on the house, you are adding a 100' of AC wiring, so you > need to make sure that any voltage drop does not cause the inverter to > operate at too high an output voltage. If the utility service has already > higher than normal AC voltage, that could cause the inverter to shut off > due to high AC voltage. Running that distance as DC would not give you that > potential issue. You still lose some power due to voltage drop of course > (either AC or DC), but as long as that doesn't cause the inverter to > operate below its MPPT DC voltage window, it won't effect it. > > > > In either case, you will need an approved disconnect at each location, in > other words, on each end of that 100' line. And good signage. > > > > And I would recommend surge/lightning protection on both ends. > > > > However, if you have the shop's inverter on the house, that also means > that you have an AC connection from the shop's Service present at the > house. This is where 230.2 may apply. You have two separate buildings with > two separate Services. 230.2 applies to single, or physically connected, > buildings with multiple Service entrances. It's about safety, so that fire > fighters or other emergency personnel can be sure that if they pull a > service meter, that they are cutting all the power to that structure. If > you have an AC connection to that other Service, the AHJ may take issue > with it under 230.2, even if you have a lockable disco, good signage, and > the house meter and shop disco are close together. You should consult with > your AHJ. > > > > Brian Teitelbaum > > AEE Solar > > > > > > > > > > *From:* [email protected] [mailto: > [email protected]] *On Behalf Of *Nathan Charles > *Sent:* Friday, March 14, 2014 2:23 PM > > *To:* RE-wrenches > *Subject:* Re: [RE-wrenches] Two systems on one building with separate > services > > > > No, the shop service is located on the shop building. > > > > -N > > > > On Fri, Mar 14, 2014 at 4:52 PM, Brian Teitelbaum < > [email protected]> wrote: > > Are both services (and meters) on the house? Or is the shop service > located on the shop building? > > > > Brian > > > > *From:* [email protected] [mailto: > [email protected]] *On Behalf Of *Nathan Charles > *Sent:* Friday, March 14, 2014 1:43 PM > *To:* RE-wrenches > *Subject:* Re: [RE-wrenches] Two systems on one building with separate > services > > > > The distance between the building is about 100'. > > > > The residential service is a 200A service but the workshop is 400A because > of large of equipment and can't be combined at this point. > > > > > > On Fri, Mar 14, 2014 at 4:03 PM, Brian Teitelbaum < > [email protected]> wrote: > > Nathan, > > > > What is the distance between the buildings, and where are the utility > meters located? > > > > What are the sizes of the Services? 200A? > > > > Can both buildings be powered from a single Service? Why is the workshop > metered separately? > > > > Brian Teitelbaum > > AEE Solar > > > > *From:* [email protected] [mailto: > [email protected]] *On Behalf Of *Nathan Charles > *Sent:* Friday, March 14, 2014 12:05 PM > *To:* RE-wrenches > *Subject:* [RE-wrenches] Two systems on one building with separate > services > > > > Hi Wrenches, > > > > I've got an issue that's got me stumped and I was hoping somebody could > give me some suggestions. > > > > We have a customer who has two meters, one on the house and one on a > workshop. The workshop is heavily shaded and it's zoned residential so > meter aggregation isn't a possibility. The customer is hoping to put two > separate PV systems on the house one for each meter with the inverters > mounted in the garage. It seems like that sets me afoul of the intentions > of 230.2 Number of services, but if I remote one set of inverters and run > DC I'm not quite sure how to think through the disconnecting requirements. > > > > Any advice or suggestions on if or how this might be possible? > > > > -- > > Nathan Charles > > Engineer > > NABCEP Certified PV Installation Professional #042013-20 > > Paradise Energy Solutions > > > > > _______________________________________________ > List sponsored by Home Power magazine > > List Address: [email protected] > > Change email address & 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 > > > > > > -- > > Nathan Charles > > Engineer > > NABCEP Certified PV Installation Professional #042013-20 > > Paradise Energy Solutions > > (717) 283-2021 direct > > > _______________________________________________ > List sponsored by Home Power magazine > > List Address: [email protected] > > Change email address & 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 > > > > > > -- > > Nathan Charles > > Engineer > > NABCEP Certified PV Installation Professional #042013-20 > > Paradise Energy Solutions > > (717) 283-2021 direct > > _______________________________________________ > List sponsored by Home Power magazine > > List Address: [email protected] > > Change email address & 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 > > > -- Nathan Charles Engineer NABCEP Certified PV Installation Professional #042013-20 Paradise Energy Solutions (717) 283-2021 direct
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