Drake,
They will not let you eliminate the box with the main breaker since the conductors are run through the building. You are back to a load side connection. However, since there are no loads pulled off that conductor to the residential panel before the panel, connecting to the line side of the residential panel makes it impossible to overcurrent the conductor. Most inspectors will accept this method. The PV system will have to have a fused disconnect at least as large as 125% of the sum of the full-current ratings for the group of inverters, but it could be up to the ampacity of the wire (I believe you said this was a 200-amp service). As long as you are feeding the service conductor from the opposite end as the supply breaker, and there are no loads taken off that supply conductor until the residential panel, you can make the argument that the sum of the supply breakers is only 200-amps. That is because there is a 200-amp breaker at one end, and a 200-amp breaker (PV) at the other end (the conductor only can be supplied by 200-amps in either direction). In any fault analysis scenario you can conjure up, there is no way to overcurrent the conductor. Even a dead short in the wire can only carry 200-amps from each direction-that is acceptable in standard fault analysis because the current flow at the fault is disregarded. You have met the requirements of 690.64 (B). If you put it in the residential panel, you must comply with the 120% rule--for now. Bill. From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Drake Chamberlin Sent: Thursday, July 31, 2008 7:53 PM To: RE-wrenches Subject: Re: [RE-wrenches] Gray code area Bill, That is a great point. As it stands, the box ahead of the residence does contain a main breaker. If we get rid of that breaker and turn it into a lugs only panel, it would satisfy the requirements. I wonder how that would pan out, since the wiring runs through this other building. Thanks, Drake At 12:49 PM 7/31/2008, you wrote: Content-Type: multipart/alternative; boundary="----=_NextPart_000_006F_01C8F303.83492700" Content-Language: en-us Drake, 690.64 relates everything to the service disconnects. All the rest of this is semantics. As long as the PV connection is upstream of the service disconnect (i.e. in between the service disconnect and the service meter), it is considered a line side service connection. If there is no way to turn off the residential service in the panel with the "feed-thru" lugs, there is no service disconnect for the residential service yet. That way if the connection were on the line side of the first service disconnect for the residence (one of two services at the site, both coming from the same service drop-to get all the semantics proper), it is considered a line-side connection. So what is it..? Bill. From: [EMAIL PROTECTED] [ <mailto:[EMAIL PROTECTED]> mailto:[EMAIL PROTECTED] On Behalf Of Drake Chamberlin Sent: Thursday, July 31, 2008 9:13 AM To: RE-wrenches Subject: Re: [RE-wrenches] Gray code area At 03:24 PM 7/30/2008, you wrote: According to the two paragraphs above, the commercial building has two commercial services??? One will receive PV and one will not?? One service is for the commercial building and one is for the residence. There is one service drop to two meters. Both services will be fed PV. Drake Chamberlin Athens Electric OH License 44810 CO License 3773 740-448-7328 303-328-5533 _______________________________________________ List sponsored by Home Power magazine [email protected] http://lists.re-wrenches.org/listinfo.cgi/re-wrenches-re-wrenches.org List rules & etiquette: http://www.re-wrenches.org/etiquette.htm Check out participant bios: www.mrsharkey.com/wrenches/ Drake Chamberlin Athens Electric OH License 44810 CO License 3773 740-448-7328 303-328-5533
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