Steven, I don't think the 60A disconnect for the line-side tap would qualify as part of the required 100A rating for the residential service. You aren't using it to supply the house loads. Unless I'm missing something, your proposal limits the residential service load to only 60A. I suppose you could argue it with the AHJ... but I think you're going against the intent of the code. These sections weren't written with any consideration to grid-tied PV feed-ins.
-Hans Frederickson -----Original Message----- From: re-wrenches-boun...@lists.re-wrenches.org [mailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of Steven Lawrence Sent: Wednesday, March 31, 2010 11:04 AM To: re-wrenches@lists.re-wrenches.org Subject: Re: [RE-wrenches] Supply Side Tap Overcurrent Protection 230.80 "Where the service disconnecting means consists of more than one switch or circuit breaker, as permitted by 230.71, the combined ratings of all the switches or circuit breakers used shall not be less than the rating required by 230.79" Steven Lawrence ___________________________________ Message: 1 Date: Wed, 31 Mar 2010 10:24:17 -0700 From: "Hans Frederickson" <h...@fredelectric.com> To: "'RE-wrenches'" <re-wrenches@lists.re-wrenches.org> Subject: Re: [RE-wrenches] Supply Side Tap Overcurrent Protection Message-ID: <71328cbb96b745889f63e627c93e8...@frederickson.local> Content-Type: text/plain; charset="us-ascii" Anything less than a 100A main is a no-go a for residential service: NEC 230.79(C): "For a one-family dwelling, the service disconnecting means shall have a rating of not less than 100 amperes, 3-wire." Also, I don't think any AHJ is going to accept a load calculation in lieu of proper bus sizing in the service. What's to stop the owner from adding loads later on? I agree with Eric... time for a service upgrade. -Hans Frederickson -----Original Message----- From: re-wrenches-boun...@lists.re-wrenches.org [mailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of Steven Lawrence Sent: Wednesday, March 31, 2010 9:54 AM To: re-wrenches@lists.re-wrenches.org Subject: Re: [RE-wrenches] Supply Side Tap Overcurrent Protection Why can't you do a line side tap and downsize the main breaker? Use a 60A main disconnect for the line side tap, and use a 60A main breaker for the service panel. That's similar to what I did except I downsized the 200A main to a 150A. This also allowed a manual interlock kit in the main service panel that can be fed from the backup load panel. Steven Lawrence _______________________________________________ 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 _______________________________________________ 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
