I second Allan's move to 48 v; that's usually what we've ended up doing in very similar situations, to keep the existing 'monsta' cable. Usually they have a dated mod sine inverter, so the upgrade to Outback improves the system coming and going. As much as I loved the SW series inverters, their time has come and gone. They don't last forever, and even if parts are available, they're almost $1200 to repair.
R. Walters r...@solarray.com Solar Engineer On Oct 20, 2010, at 12:37 PM, Allan Sindelar wrote: > Jay, > When we faced this issue recently, we used it as an opportunity to upgrade to > a 48V system. The obsolescence and lack of Schneider support for the SW4024 > contributed to the logic of this approach. > > At 48V an MX60 will handle 3200 watts. > > Allan Sindelar > al...@positiveenergysolar.com > NABCEP Certified Photovoltaic Installer > EE98J Journeyman Electrician > Positive Energy, Inc. > 3201 Calle Marie > Santa Fe, New Mexico 87507 > 505 424-1112 > www.positiveenergysolar.com > > On 10/20/2010 11:58 AM, jay peltz wrote: >> >> Hi Ray et all, >> >> The customer has 200' of 4/0 direct buried with a 24v system, and is running >> close to 60 amps now, and wants to add 6 more 215 watt modules. >> So the issue has been to try and find a way around putting in another wire >> ie digging a new trench through his yard. >> >> the client may be willing to try and see how it goes with the controllers, >> at this point hes aware that it could blow up and its not a warranty issue. >> >> Will keep you up to date about what smokes or not. >> >> j >> >> peltz power >> >> On Oct 20, 2010, at 10:18 AM, R Ray Walters wrote: >> >>> Hi Jay; >>> >>> I'd second (3rd, 4th?) everyone else's comments that it probably isn't a >>> good idea. >>> I'd add that the diode will eat at least a volt, so that's not good for >>> MPPT, or balancing. >>> The one possible way to do this, might be to use a Vanner battery >>> equalizer, which is designed to split an incoming charge source, and feed 2 >>> batteries, without letting them >>> "see" each other. I think they're only good for 24 v, though, so that might >>> not work for your situation. >>> The only other way I could see, is using a huge relay ( or paralleled >>> relays) controlled by a C40 (or similar). You would lose both MPPT and PWM, >>> and be back in the solar stone age (90s) though. >>> >>> TIme to pull out the 2 big cables, and pull 4 smaller ones? >>> Have fun, I actually like retrofitting old off grid stuff; it presents all >>> sorts of interesting challenges like this. >>> >>> R. Walters >>> r...@solarray.com >>> Solar Engineer >>> >>> >> _______________________________________________ >> 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 >
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