[RE-wrenches] Two systems on one building with separate services

[Nathan Charles]

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
<bteitelbaum at aeesolar.com>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:* re-wrenches-bounces at lists.re-wrenches.org [mailto:
> re-wrenches-bounces at lists.re-wrenches.org] *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 <
> bteitelbaum at aeesolar.com> wrote:
>
> Are both services (and meters) on the house? Or is the shop service
> located on the shop building?
>
>
>
> Brian
>
>
>
> *From:* re-wrenches-bounces at lists.re-wrenches.org [mailto:
> re-wrenches-bounces at lists.re-wrenches.org] *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 <
> bteitelbaum at aeesolar.com> 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:* re-wrenches-bounces at lists.re-wrenches.org [mailto:
> re-wrenches-bounces at lists.re-wrenches.org] *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
>
>
>
>
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> --
>
> 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: RE-wrenches at lists.re-wrenches.org
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> --
>
> 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: RE-wrenches at lists.re-wrenches.org
>
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-- 
Nathan Charles
Engineer
NABCEP Certified PV Installation Professional #042013-20
Paradise Energy Solutions
(717) 283-2021 direct
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