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" <[email protected]> To: "'RE-wrenches'" <[email protected]> Subject: Re: [RE-wrenches] Supply Side Tap Overcurrent Protection Message-ID: <[email protected]> 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: [email protected] [mailto:[email protected]] On Behalf Of Steven Lawrence Sent: Wednesday, March 31, 2010 9:54 AM To: [email protected] 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: [email protected] 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
