Jeff's idea is good, but I think the only potential violation of the listing of the service panel, would be if you drilled and tapped into the buss bar. Tapping the cable w/ a listed connector shouldn't cause any trouble to the service panel. (230.33 specifically allows the service cable splice) Connections and taps of wires are allowed in the service panel just like in a J box. (but comply with 312.7 and 312.8 about providing adequate space for the splice) You can fill the wiring area (measure its cross section) up to 75% including the taps. but only 40% fill of the conductors themselves. The calculation is made the same way you would calculate wire fill for conduit, only you will need dimensions of the Polaris, or other type of tap. (you may need to use a lower profile tap in this case, too) I think if you can show the AHJ these code sections, and some solid wire fill calculations (cables + taps < 75%, and cables only < 40%), you should be good to go. Picky yes, but as another recent thread lamented about lax enforcement, your super -diligent AHJ will help weed out your less knowledgable competition.
R. Walters [email protected] Solar Engineer On Jun 17, 2010, at 10:20 AM, Jeff Irish wrote: > If possible, install a j-box between the meter and MSP, run the service > entrance conductors through it unbroken and through Polaris type connectors > for the tap. > > Jeff Irish > Hudson Valley Clean Energy > > From: [email protected] > [mailto:[email protected]] On Behalf Of Jeff Oldham > Sent: Thursday, June 17, 2010 12:14 PM > To: [email protected] > Subject: [RE-wrenches] Supply side tap not allowed > > I just had my proposal for a supply side tap (between meter and main) of on a > residential system rejected by the inspector (CA) because he wants a letter > from the service panel manu detailing the proper method of making this tap > and that I must strictly follow it. This is a 1st for me, I've done lot's of > commercial supply side taps as well as residential in numerous jurisdictions > and this has never been requested. To make matters worse, the manu of this > service is Zinsco, no letters are coming from this long ago defunct company. > IF you could even get any manu to do this how many months do you think it > would take to get and after how many prods? > > The inspector acknowledges that the NEC allows for supply side taps w/PV > systems as well as noting that nowhere in the NEC does it require this > permission letter. He says he found discussion about it on the 'net and that > some feel the taps violate the U.L. on the panel. I can see this take, but > feel a simple tap is not a significant "modification" to a listed panel and > the impacts on our installs is significant as those letters will not come > easy. > > Any thoughts? > > Thanks, > > -jeff o > > > >From the Solar, Wind and Hydro powered office of Jeff Oldham/Regenerative > >SOLutions > > > ____________________________________________________________ > Ditech® Official Site > Fast & Friendly Service. Apply Online and Start Saving Today! > Ditech.com_______________________________________________ > 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 >
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