Peter, No--is that short enough.
Imax is defined by 690.8(A). Imax is the value used for doing all conditions of use calculations including temperature corrections, conduit fill, and sunlight impact. The overcurrent protection device (OCPD) must be sized to 125% of Imax for continuous operation of the OCPD. In other cases in the NEC, conditions of use are not considered in the sizing of OCPD, so it follows that 690.8(B) should not either. There is a proposal to the 2011 NEC to clarify this in 690.8(B). How's that. Bill. -----Original Message----- From: re-wrenches-boun...@lists.re-wrenches.org [mailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of Peter Parrish Sent: Thursday, January 08, 2009 1:20 PM To: 'RE-wrenches' Subject: [RE-wrenches] Cable Sizing Boy did I light one off. Can I steer an enlightened soul back to my specific question: "In specific: if we have two DC PV circuits (4 wires: 2 positive, 2 negative) in EMT and we have taken into account the "PV 125% circuit current calculation", "cable sizing of 125% for proper operation of overcurrent devices", and cable derating for temperature -- do we now apply the derating from B.310.11 for 4-6 wires?" Peter T. Parrish, President California Solar Engineering, Inc. 820 Cynthia Ave., Los Angeles, CA 90065 Ph 323-258-8883, Mobile 323-839-6108, Fax 323-258-8885 CA Lic. 854779, NABCEP Cert. 031806-26 peter.parr...@calsolareng.com _______________________________________________ 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
