Re: [RE-wrenches] 600V charge controller questions
We were called in on a system similar to this, and we ended up just installing an AC transfer switch. Normally the GT array sold back to the grid side of the system, but in an extended outage, the customer had the option to switch the connection to the back up load side (AC coupled) He was made aware that battery regulation could be an issue, and to switch off the GT array when the batteries got even close to full. Obviously this would not be acceptable in a full time off grid system, but this option could save your bacon in the very occasional long outage. It boils down to: Is it better to let the batteries remain discharged and the customer to have no power, or take a chance on over charging the batteries in an emergency? Essentially, the system would remain full proof until they manually switched in the AC coupled system. I look at this sort of like any other manual over ride switch: don't use it unless you understand the consequences, and really need it. Add strongly worded warning stickers: " Danger Battery damage could result, Emergency use only!" The other options you are considering would certainly be better, but at significantly more cost. R.Ray Walters CTO, Solarray, Inc Nabcep Certified PV Installer, Licensed Master Electrician Solar Design Engineer 303 505-8760 On 1/30/2016 3:21 PM, Allan Sindelar wrote: Wrenches, I am serving as a consultant for a homeowner with an array of solar equipment that doesn't do what he wants, a common story. He wants independence in the event of an extended utility outage. To cut to the chase: He has one array of 3,100 watts feeding through a controller into a 48V battery bank. No issues with this. A second array of 4,230 rated watts (2 9-module strings of 235W Sharp modules) currently feeds a Fronius IG-4000 inverter and the grid. In the event of an outage this system shuts down, of course. He is looking at replacing his existing pair of old SW5548s with a single Schneider XW system, or possibly a Radian. I would like to give him the ability to switch from the Fronius inverter to a 600V charge controller if either a) the grid went down or b) the Fronius failed. I looked at Morningstar's TS-MPPT-600 controller with the DC transfer switch, but its DC output is rated as limited to 60A, less than the 4.2kW output of the array. The spec sheet gives a nominal maximum wattage of 3,200W, although a note adds that "input power can exceed Nominal Maximum Operating Power, but controller will limit and provide its rated continuous maximum output current into batteries. This will not harm the controller." I looked at Schneider's XW MPPT80 controller, which has the necessary higher capacity. But beside lacking any built-in or optional input metering, it lacks the transfer switch available with the Morningstar. So questions: - Is there a good transfer switch to use with the Schneider unit, to allow manual switching of the PV input between the Fronius (when the grid is up) and the controller and batteries (when the grid is down)? - Should I use the Morningstar unit, recommending that the periodic flatlining due to the excess wattage be simply accepted as a small concession to being able to use the array during an extended outage? - Is AC coupling simply a better approach? - Any other solutions? Thanks, Allan -- *Allan Sindelar* al...@sindelarsolar.com NABCEP Certified PV Installation Professional NABCEP Certified Technical Sales Professional New Mexico EE98J Journeyman Electrician Founder (Retired), Positive Energy, Inc. *505 780-2738 cell* ** ___ List sponsored by Redwood Alliance List Address: RE-wrenches@lists.re-wrenches.org Change listserver email address & settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/maillist.html List rules & etiquette: www.re-wrenches.org/etiquette.htm Check out or update participant bios: www.members.re-wrenches.org ___ List sponsored by Redwood Alliance List Address: RE-wrenches@lists.re-wrenches.org Change listserver email address & settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/maillist.html List rules & etiquette: www.re-wrenches.org/etiquette.htm Check out or update participant bios: www.members.re-wrenches.org
[RE-wrenches] Enphase M190 current limiting
I just noticed that several of our sites with Enphase M190s are current limiting at 140 watts. These units used to clip at 199 watts so I feel like our customers just lost a potential 30% of their power output. It appears to be related to a firmware update 520-8-r01-v01.08.00. We've got one site with just 8 units, 1 of them got this firmware update back in September and has been limiting to 140w since then, 5 of them got this update in late January and have been limiting to 140w since then, the other two are at a previous firmware version and are performing as we would expect up to 199w. Have any of you noticed this same thing? Do you know what this is about? It doesn't feel very fair on the user end of things. Sincerely, Rebecca Lundberg Powerfully Gree n Minnesota ___ List sponsored by Redwood Alliance List Address: RE-wrenches@lists.re-wrenches.org Change listserver email address & settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/maillist.html List rules & etiquette: www.re-wrenches.org/etiquette.htm Check out or update participant bios: www.members.re-wrenches.org
[RE-wrenches] Aquion Batteries
Our utility wanted to add a new capacity and demand charge to all solar customers' bills. And the new California Public Utilities Commission decision on net metering included a mandate for new solar installs to join Time of Use pricing by 2019. This seems to be the trend that many grid connected PV installers are going to have to adapt to. While this version of Aquion may not handle surges, we might all benefit by adapting demand side hardware like the Energy Sentry http://energysentry.com/PP-residential-controllers.php to change the shapes and timing of our loads. Whether on or off grid, this might be a value-added product we could offer our customers and possibly make new batteries more compatible. Bill Dorsett Manhattan, KS 66502 ___ List sponsored by Redwood Alliance List Address: RE-wrenches@lists.re-wrenches.org Change listserver email address & settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/maillist.html List rules & etiquette: www.re-wrenches.org/etiquette.htm Check out or update participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] 600V charge controller questions
Allan, you could network multiple Morningstar 600v controllers for the output ampacity required (up to 4 controllers, ...yeah, I know they are expensive). Would you even need a transfer switch? Why not just wire Fronius IG and Morningstar controller inputs in parallel (with associated fuses and disconnects of course). Once batteries are charged and in float, the array then would be available to the IG to sell to the grid. If the IG goes down (which it prob will eventually) then the MS 600v controller will charge the batts enough to get by. Seems like it would work, am I missing something? RoyR Roy Rakobitsch NABCEP Certified Small Wind Installer® Certified Advanced Tower Climbing, Safety & Rescue Wind/PV Design Engineer Windsine LLC 631-514-4166 www.windsine.org On Sun, Jan 31, 2016 at 1:14 PM, Ray Walterswrote: > We were called in on a system similar to this, and we ended up just > installing an AC transfer switch. Normally the GT array sold back to the > grid side of the system, but in an extended outage, the customer had the > option to switch the connection to the back up load side (AC coupled) > He was made aware that battery regulation could be an issue, and to switch > off the GT array when the batteries got even close to full. Obviously this > would not be acceptable in a full time off grid system, but this option > could save your bacon in the very occasional long outage. > It boils down to: Is it better to let the batteries remain discharged and > the customer to have no power, or take a chance on over charging the > batteries in an emergency? > Essentially, the system would remain full proof until they manually > switched in the AC coupled system. I look at this sort of like any other > manual over ride switch: don't use it unless you understand the > consequences, and really need it. Add strongly worded warning stickers: " > Danger Battery damage could result, Emergency use only!" > The other options you are considering would certainly be better, but at > significantly more cost. > > R.Ray Walters > CTO, Solarray, Inc > Nabcep Certified PV Installer, > Licensed Master Electrician > Solar Design Engineer303 505-8760 > > On 1/30/2016 3:21 PM, Allan Sindelar wrote: > > Wrenches, > I am serving as a consultant for a homeowner with an array of solar > equipment that doesn't do what he wants, a common story. He wants > independence in the event of an extended utility outage. To cut to the > chase: > > He has one array of 3,100 watts feeding through a controller into a 48V > battery bank. No issues with this. > A second array of 4,230 rated watts (2 9-module strings of 235W Sharp > modules) currently feeds a Fronius IG-4000 inverter and the grid. In the > event of an outage this system shuts down, of course. He is looking at > replacing his existing pair of old SW5548s with a single Schneider XW > system, or possibly a Radian. > I would like to give him the ability to switch from the Fronius inverter > to a 600V charge controller if either a) the grid went down or b) the > Fronius failed. > > I looked at Morningstar's TS-MPPT-600 controller with the DC transfer > switch, but its DC output is rated as limited to 60A, less than the 4.2kW > output of the array. The spec sheet gives a nominal maximum wattage of > 3,200W, although a note adds that "input power can exceed Nominal Maximum > Operating Power, but controller will limit and provide its rated continuous > maximum output current into batteries. This will not harm the controller." > > I looked at Schneider's XW MPPT80 controller, which has the necessary > higher capacity. But beside lacking any built-in or optional input > metering, it lacks the transfer switch available with the Morningstar. > > So questions: > - Is there a good transfer switch to use with the Schneider unit, to allow > manual switching of the PV input between the Fronius (when the grid is up) > and the controller and batteries (when the grid is down)? > - Should I use the Morningstar unit, recommending that the periodic > flatlining due to the excess wattage be simply accepted as a small > concession to being able to use the array during an extended outage? > - Is AC coupling simply a better approach? > - Any other solutions? > > Thanks, Allan > > -- > > *Allan Sindelar* > al...@sindelarsolar.com > NABCEP Certified PV Installation Professional > NABCEP Certified Technical Sales Professional > New Mexico EE98J Journeyman Electrician > Founder (Retired), Positive Energy, Inc. > *505 780-2738 <505%20780-2738> cell* > > > > > ___ > List sponsored by Redwood Alliance > > List Address: RE-wrenches@lists.re-wrenches.org > > Change listserver email address & > settings:http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org > > List-Archive: > http://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/maillist.html > > List rules & etiquette:www.re-wrenches.org/etiquette.htm > > Check out or