<br>Regarding the DC disco issue, we have identified the 3-pole, 600Vdc rated, 200A Crouse-Hinds CH364R (<a href="http://www.crouse-hinds.com/crousehinds/newproducts/relatedinfo/Solar%20Combiner%20Brochure%20110309.pdf">http://www.crouse-hinds.com/crousehinds/newproducts/relatedinfo/Solar%20Combiner%20Brochure%20110309.pdf</a>) as a replacement for the Square D version. Its a little pricey but it looks like the best available option these days. We are also looking at the SolarBOS disconnecting combiners - does anyone have any experience with them?<br>
<br><br>Andrew Truitt<br>Standard Solar Inc.<br><br><br><br><br><div class="gmail_quote">On Wed, Apr 14, 2010 at 3:07 AM, Philip Boutelle <span dir="ltr"><<a href="mailto:philboutelle@gmail.com">philboutelle@gmail.com</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin: 0pt 0pt 0pt 0.8ex; border-left: 1px solid rgb(204, 204, 204); padding-left: 1ex;">Kirpal and Wrenches,<br><br>Can you describe your battery setup with the four Sunny Islands? SMA recommends using two parallel 1/0 conductors to each SI DC disconnect, for three reasons: wire fill limitations with the 1.5" knockouts they provide, ease of landing in the breaker, and because the 125A breaker is double-barreled and rated for 125A on each leg with the current flow not necessarily symmetric, so you need a rating of approx. 200A on the parallel conductors (I'm quoting Martin and Antonio at SMA here, this detail is not in the manual but what they recommended to me as best practice. The manual at one point lists "2 x 1AWG" for the DC connections, nothing further). <br>
<br>With four SIs, that's eight positive and eight negative 1/0 conductors to be bussed from the battery bank, or at least to the SIs. I have a similar project coming up and am looking at a custom fuse/bus block from <a href="http://www.deltecco.com/" target="_blank">Deltec </a>to arrange/distribute those wires, but would love to hear other ideas and experiences on how to go from a single string of 48V batteries, through a fused DC disconnect, and then land in the 4 SIs. <br>
<br>The fused DC disconnect is also an issue; with 20kW of rated continuous power at a worst-case of 41V (numbers from the spec sheets), that's 487A *1.25 = 610A. I could break that up into four parallel conductors, enabling me to use a 4-pole 200A disconnect w/ 175A fuses (space is an issue on the mechanical wall). But do I need to pass the DC conductors through two switches on the disconnect to maintain the DC rating on the switch? And if so, should I instead use a 4-pole 400A disco with 350A fuses and double pass-through on the two positive conductors connecting to the battery bank? Or.... ?<br>
<br>
<p class="MsoNormal"><span style="font-size: 10pt;">Phil Boutelle</span><span style="font-size: 10pt;"></span></p>
<p class="MsoNormal"><span style="font-size: 10pt;">Project Engineer<br>
NABCEP Certified Solar PV Installer <sup>TM</sup><br>
Real Goods Solar, Inc.</span></p>
<p class="MsoNormal"><span style="font-size: 10pt;">831.477.0943 office<br>
831.359.5268 mobile</span><span style="font-size: 10pt;"> </span></p>
<p class="MsoNormal"><span style="font-size: 10pt;">831.477.0944 fax<br>
<a href="http://www.iesolar.com/" target="_blank"><span style="color: blue;">www.RealGoodsSolar.com</span></a></span></p><div><div></div><div class="h5">
<br><br><br><div class="gmail_quote">On Sun, Apr 11, 2010 at 7:44 PM, Kirpal Khalsa <span dir="ltr"><<a href="mailto:solarworks@gmail.com" target="_blank">solarworks@gmail.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin: 0pt 0pt 0pt 0.8ex; border-left: 1px solid rgb(204, 204, 204); padding-left: 1ex;">
<div>Dave----this is exactly what the sunny island is capable of.....supply the house panel from the sunny island output, and the main panel in the barn to the input side, the house panel will run full time via the sunny islands, install a MANUAL transfer switch for times when the sunny islands may need to be turned off or removed for maintenance, I can't remember all the parameters of the programable relays in the sunny island but more than likely one of them is a warning, possibly to notify of no AC source. also you can pass power thru the relays in the sunny islands so no external relay is required. the beautiful thing about the sunny island/sunny boy set up is you actually are able to get a full multi stage charge process on your batteries during a power outage unlike most other AC coupled combinations which are simply a charge or no charge, taper not included. </div>
<div>there are 2 programmable relays on each sunny island so in a dual inverter system you still have other relays available for other things like battery room fan control, or gen start. </div><div>we have a similar system to yours up and running using 4 sunny islands and 4 sunny boys, flawlessly so far......</div>
<div>good luck..</div><div>For technical help or advice for your system I strongly recommend talking to Tucker in the service department over at SMA.......he knows the ac coupling set up, and system commissioning steps really well and will be able to make your job easy.....</div>
<div><br></div><div>-- <br>Sunny Regards,<br>Kirpal Khalsa<div><br>NABCEP Certified Solar PV Installer<br></div>Renewable Energy Systems<br><a href="http://www.oregonsolarworks.com" target="_blank">www.oregonsolarworks.com</a><br>
541-218-0201 m<br>
541-592-3958 o</div><div><br></div><br><div class="gmail_quote">2010/4/11 Richard L Ratico <span dir="ltr"><<a href="mailto:Richard.L.Ratico@valley.net" target="_blank">Richard.L.Ratico@valley.net</a>></span><div><div>
</div><div><br><blockquote class="gmail_quote" style="margin: 0pt 0pt 0pt 0.8ex; border-left: 1px solid rgb(204, 204, 204); padding-left: 1ex;">
Hi Dave,<br>
<br>
Depending on the house loads, you might very well do without an additional (very<br>
expensive) auto transfer switch. The inverters, of course, already have one.<br>
Just leave the Sunny Islands connected 24/7. The transfer from grid to battery<br>
is then milliseconds and flawless. The 56 amps continuous, and deep SI surge<br>
capacity will most likely, comfortably, handle the whole shebang. I've got a<br>
single SI5048 doing this now through a transformer. Works great.<br>
<br>
Put a manual transfer switch at the barn in the event there's ever a problem<br>
with the SI's. But, Iota makes a 100 Amp auto transfer switch, if you decide<br>
you've got to have one. It is attractively priced compared to anything else I<br>
could find. Beware, it may not be UL listed. I've got one, haven't used it yet.<br>
Let me know if you're interested :-)<br>
<br>
During a recent severe weather event, our customer's utility was down for 5<br>
days. Battery lasted 24 hours before shutting down the system to self-protect,<br>
as designed and programmed. We had to round up a generator in a hurry to "backup<br>
the backup". A previously installed a manual transfer switch, with the exterior<br>
generator inlet, made that relatively painless, but it was something we hoped<br>
would never be needed. As you know, you also need SMA communication boards and<br>
the SMA programming cable to get the Sunny Boy to work with the SI's when the<br>
grid is down.<br>
<br>
Regards,<br>
Dick Ratico<br>
Solarwind Electric<br>
<br>
<br>
I<br>
<div><div></div><div><br>
--- You wrote:<br>
We have a new (for us) application for grid connected net-metered PV with<br>
battery back-up as follows. The twist is that the entire load center in the<br>
house will be the "protected loads panel".<br>
<br>
- 5kW PV ground mount located 250 feet East of their barn.<br>
<br>
- Will utilize AC Coupled SB5000US inverter to (2)Sunny Island<br>
5048's for 120/240VAC back-up capability with 24.5kWh back-up battery bank.<br>
All inverters/batteries to be located in barn.<br>
<br>
- Barn has 200A service from grid (PV system AC point of connection<br>
will be there), house is located 175 feet West of barn and has a 100A load<br>
center (sub panel from barn).<br>
<br>
- Intention is to back up house as the protected loads panel fed by<br>
the Sunny Islands in case of grid failure.<br>
<br>
- The Sunny Islands will be able to pass through up to 56 Amps at<br>
240VAC.<br>
<br>
- I want to supply the 100A house load center with up to 100A<br>
during normal operation with grid available. I am proposing to use an<br>
automatic contactor/transfer switch to feed the 100A house load center.<br>
Normally Closed contacts from grid power, N.O. contacts fed by Sunny Island.<br>
Therefore normal operation will be for grid to be connected directly to<br>
house 100A load center and under grid failure the transfer switch will<br>
connect the Sunny Islands to power the 100A house load center. Under grid<br>
failure condition we will have an LED signal light come on to warn the<br>
homeowners that they are on battery power.<br>
<br>
Questions for wrenches:<br>
<br>
1) Is that whole thing a viable idea?<br>
<br>
2) 100 Amp automatic transfer switch recommendations?<br>
<br>
3) LED signal light recommendations? Or is there another method to<br>
warn homeowner of grid down status?<br>
<br>
<br>
<br>
Thanks,<br>
<br>
<br>
<br>
Dave<br>
<br>
<br>
<br>
David Palumbo, NABCEP Certified PV Installer<br>
</div></div>--- end of quote ---<br>
<div><div></div><div>_______________________________________________<br>
List sponsored by Home Power magazine<br>
<br>
List Address: <a href="mailto:RE-wrenches@lists.re-wrenches.org" target="_blank">RE-wrenches@lists.re-wrenches.org</a><br>
<br>
Options & settings:<br>
<a href="http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org" target="_blank">http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org</a><br>
<br>
List-Archive: <a href="http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org" target="_blank">http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org</a><br>
<br>
List rules & etiquette:<br>
<a href="http://www.re-wrenches.org/etiquette.htm" target="_blank">www.re-wrenches.org/etiquette.htm</a><br>
<br>
Check out participant bios:<br>
<a href="http://www.members.re-wrenches.org" target="_blank">www.members.re-wrenches.org</a><br>
<br>
</div></div></blockquote></div></div></div><br><br clear="all"><br><br>
<br>_______________________________________________<br>
List sponsored by Home Power magazine<br>
<br>
List Address: <a href="mailto:RE-wrenches@lists.re-wrenches.org" target="_blank">RE-wrenches@lists.re-wrenches.org</a><br>
<br>
Options & settings:<br>
<a href="http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org" target="_blank">http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org</a><br>
<br>
List-Archive: <a href="http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org" target="_blank">http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org</a><br>
<br>
List rules & etiquette:<br>
<a href="http://www.re-wrenches.org/etiquette.htm" target="_blank">www.re-wrenches.org/etiquette.htm</a><br>
<br>
Check out participant bios:<br>
<a href="http://www.members.re-wrenches.org" target="_blank">www.members.re-wrenches.org</a><br>
<br>
<br></blockquote></div><br>
</div></div><br>_______________________________________________<br>
List sponsored by Home Power magazine<br>
<br>
List Address: <a href="mailto:RE-wrenches@lists.re-wrenches.org">RE-wrenches@lists.re-wrenches.org</a><br>
<br>
Options & settings:<br>
<a href="http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org" target="_blank">http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org</a><br>
<br>
List-Archive: <a href="http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org" target="_blank">http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org</a><br>
<br>
List rules & etiquette:<br>
<a href="http://www.re-wrenches.org/etiquette.htm" target="_blank">www.re-wrenches.org/etiquette.htm</a><br>
<br>
Check out participant bios:<br>
<a href="http://www.members.re-wrenches.org" target="_blank">www.members.re-wrenches.org</a><br>
<br>
<br></blockquote></div><br><br clear="all"><br>-- <br>"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!"<br>
<br>~William McDonough<br><br>