Jeff - We have a number of systems with exactly that configuration and we haven't had any issues. However, we have not installed the XW/SB combination since Xantrex (Schneider?) rolled out the firmware that incorporates the high battery frequency shift to shut down the solar inverter(s). We switched to the Sunny Island for a time but are now going back to the XW/SB configuration because of the issues you mentioned as well as the lack of a bypass switch on the Sunny Island. I think we have an XW/SB system upcoming so I will get back to you if we have any issues. Could your problem have something to do with the ironius, self-clearing GFCI faults that have plagued Sunny Boys recently?
Regarding your next post on utility disconnects for AC coupled systems, we install the disco between the solar and the critical loads panel. I was not aware that the XW (or the Sunny Island) could be re-programmed to send power out the AC input terminals. I guess I should investigate that... Enjoy this beautiful weekend! Andrew Truitt Standard Solar Inc. On Sat, Apr 17, 2010 at 8:41 AM, Jeff Yago <jry...@netscape.com> wrote: > As mentioned before, many of our clients want battery backup with their > solar, but are not off-grid. They also want a generator so battery banks > can be down-sized. For many of these applications we use a SunnyBoy at the > array when the aray is located hundreds of feet from house, and usually a > Xantrex battery based inverter at the house, and backfeed the solar inverter > into the inverter's emergency loads panel. We pass this backfeed through a > heavy duty relay controlled to open on high battery voltage. Yes, SunnyBoy > with SunnyIsland is better match, but since one is 120 V and the other is > 240V that means adding transformers or using two SunnyIslands. > > Here is the issue - The SunnyBoy is working perfectly when grid power is > passing back to it through the backfeed connection. However, when this > system operating off-grid when the grid is lost, the SunnyBoy "sees" the > fake grid power coming from the Xantrex which it shows on L1 and L2 > readings, but it is staying in the waiting mode and will not connect. No > errors, just acts like grid a morning startup and stays that way. I have > had problems before with Fronius doing this and they have provided secret > codes to open up the program settings for the grid which solves the problem > when grid power is poor quality typical at end of line. Is this solution > possible with SunnyBoy inverters, or is there something else going on. Have > not had this problem on other AC coupled systems using the same combination > of inverters. > > Thanks, > > Jeff Yago > > _____________________________________________________________ > Netscape. Just the Net You Need. > _______________________________________________ > 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 > > -- "Don't get me wrong: I love nuclear energy! It's just that I prefer fusion to fission. And it just so happens that there's an enormous fusion reactor safely banked a few million miles from us. It delivers more than we could ever use in just about 8 minutes. And it's wireless!" ~William McDonough
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