Hi Ray, This works very well with the SI's. We have an off grid, dual SI system in the Bahamas which uses 5 Classics and 20 kW of PV, along with a 60 kW generator. It's been in for about 6 months and the client is very pleased. Midnite makes a nice pre-wired panel (8' x4'), heavy, but in off off grid it's nice to have as much pre-assembly as possible.
Daryl DeJoy NABCEP Certified PPV installer Penobscot Solar Design > I had another related question to add to using the SMA SI inverters: > Can't we still use regular charge controllers to charge the battery, and > just use the SIs as inverters, and gen in charging only? > I don't see justification for the extra cost of an AC coupled system > here. The array will be on the garage roof, with equipment below. Only > 50 ft run for the PV, so I was planning on using Midnite Classics. > > R.Ray Walters > CTO, Solarray, Inc > Nabcep Certified PV Installer, > Licensed Master Electrician > Solar Design Engineer > 303 505-8760 > > On 3/25/2014 4:21 PM, Kevin Pegg wrote: >> Hi Ray, >> >> I have several 3-phase off-grid inverter/battery/generator systems out >> there. >> >> - SMA Sunny Island is the best. Can scale to at least 180 kW, maybe >> more. Reliable & very solid. I have several sites going over 2 years >> without a single second of power outage. >> - Xantrex XW. It can work in a 3-ph config, but it's not as stable >> system. We have taken to preventatively rebooting the systems every 4 >> months and that helps a lot - at least the outage can be planned and on >> our terms. >> - Outback has had so many power quality nightmares I won't go there >> anymore. >> - I believe Magnum has a 3-ph option but haven't installed one yet. >> >> SMA inverters are more expensive. And they work very well. They also >> have a very good battery charging algorithm and integral gen start >> control. >> >> Kevin >> >> -----Original Message----- >> From: [email protected] >> [mailto:[email protected]]On Behalf Of Ray >> Walters >> Sent: March 24, 2014 6:44 PM >> To: RE-wrenches >> Subject: [RE-wrenches] 208 3 phase Off Grid Inverter >> >> >> Hi All; >> >> I'm exploring options for an off grid project with an existing 30 Kw >> Kohler wired for 208 vac 3 phase. The generator runs some 8 hp air >> compressors, so rewiring it is not an option. We're primarily >> interested in reducing gen run time from the current situation: 14 hrs/ >> day. >> So far, only the Outback VFX inverters seem capable of being wired in >> 208, 3 phase, but according to the manual they can only be stacked 1 >> inverter per leg. This limits the system to only 3 inverters total, or >> 10.8 kW. I would like expandability beyond this. >> 1) are there any other inverters available that I'm over looking? >> 2) Should I consider a transformer to convert from 208 vac/3phase to 240 >> vac/ singe phase? >> >> We're not going to even try to run the compressors, just the other >> single phase loads, mostly 120 vac, but we have a couple of small air >> conditioners, that are currently running on 208 single phase. I believe >> they would run fine on 240 vac, as they have a name plate rating at 230 >> vac. >> 3) We may possibly run 2 separate 3 inverter stacks and only tie >> together at the battery, but otherwise they would not be connected. This >> seems inefficient, and would require some load balancing of the various >> inverters. >> >> All help and discussion is greatly appreciated as always, >> > > _______________________________________________ > List sponsored by Home Power magazine > > List Address: [email protected] > > Change email address & 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: [email protected] Change email address & 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
