HI Drake I don't use the FW 500 boxes, which I'm guessing you are using. ( the FW 1000 are ok for larger wire combos) because either I'm going with a single inverter (E panel) or radian. The other way I also run paralleled wires is with larger conduit. I suggest you check out midnight for some big battery cabling boxes.
jay peltz power On Jan 2, 2015, at 3:17 PM, [email protected] wrote: > 4/0 copper is good for a 24V, 4000 W inverter. What is being used for > multiple inverters? > > I've paralleled 4/0 into outback boxes using 2, 2" PVC conduits. It gets > pretty messy trying to put 4 sets of 4/0s into enclosures and battery > boxes (although I have worked on such systems). Does anyone have clean > solutions for these systems? > > Thanks, > > Drake > > > > > >> Some other things: If you keep the conduit less than 24" long, which is >> recommended anyway for main battery connections, the conduit fill >> requirements don't apply. (see exception: 310.15(B)3a2) >> Using table 310.15(B)16 yeilds 230 amps for 4/0 at 75 C. Then 240.6 >> lists 250 amp as the next standard size of OCPD which is allowed to be >> used by 240.4(B) So you can just justify 4/0. >> Further, many manufacturers (like Midnite) use the open air ampacity >> table: 310.15(B)17, since the cable is not "in conduit" and 4/0 cable at >> 75 C is rated to 360 amps. >> The Free Air interpretation is not completely substantiated in the code >> from my read of it though. Maybe someone more knowledgable could cite >> the chapter and verse that defines when the free air rating can and >> cannot be used. >> Also remember those breakers are 100% duty cycle rated, and that the >> inverter usually can't run any where close to 250 amps continuously. >> Bottomline is we've been using 4/0 with 250 amp breakers for almost 20 >> years, and I've never seen or heard of a problem. >> >> R.Ray Walters >> CTO, Solarray, Inc >> Nabcep Certified PV Installer, >> Licensed Master Electrician >> Solar Design Engineer >> 303 505-8760 > _______________________________________________ List sponsored by Redwood Alliance List Address: [email protected] Change listserver email address & settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://www.mail-archive.com/[email protected]/maillist.html List rules & etiquette: www.re-wrenches.org/etiquette.htm Check out or update participant bios: www.members.re-wrenches.org
