I really appreciate the responses to my questions. Marv, can you address Bill L's comment that some faults could require the EnPhase EMU unit to clear? That's good point about shading which isn't a problem on this roof.
Regarding the "wasted glass" and "third module" of the KC120's. Currently these 3 modules charge a battery bank with only a few rarely used lights on it. Is used to be more frequently used but not now so the batteries are spending most of their time at float thus the glass is already wasted. The third module will continue to charge the same battery bank. Best, Travis Creswell Ozark Energy Services -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Marv Dargatz Sent: Tuesday, April 07, 2009 7:32 PM To: RE-wrenches Subject: Re: [RE-wrenches] Enphase Application Travis, You are exactly right. As long as you do not exceed the max open circuit voltage or short circuit current rating you're perfectly fine. Even if you put 300W of module on the inverter, it will just hit power limit until the irradiance declines enough to let the MPPT work again. No problem. No damage to the module or the inverter. The "smoke threshold" voltage is many volts above our stated maximum input voltage. Of course, it probably doesn't make economic sense to waste that much glass. In your case, two Kyoceras in series will work just fine. Depending on the age of the modules, soiling, etc., you'll probably have less than 240W peak. I'd guess you will seldom see the inverters hit power limit. This configuration will have no impact on MTBF or reliability. Do be aware that if you shade one of the two modules, you'll limit the output of both modules in the series string. No worse than a standard string inverter. We chose a Tyco CPC connector for cost, reliability, and environmental reasons. If you can find a connector that meets the demanding NEMA6 requirements at a better price, please let me know. We're constantly looking for ways to reduce product cost without degrading reliability. Hope this helps. See Ya! Marv Enphase Energy 707 763-4784 x7016 Travis Creswell wrote: > Greetings Wrenches, > > I have customer with a three module array made up of 120 watt Kyocera's that > charge the battery bank underutilized of “hobby system”. > > It spends most time in float plus were adding a 5.5 kW direct grid tied > array that require us to move the existing array so the customer is > interested in putting an EnPhase inverter on two of the Kyocera 120’s. > > I’ve looked over the EnPhase specs and don’t see a reason why I can’t wire > two KC120’s in series and feed the EnPhase with them. I do see them listing > it’s compatibility of up 225 watt modules but am having a hard time getting > much further. I didn’t find a max input wattage so what happens if I put > 240 watts to the EnPhase? Does the magic smoke come out on day one or does > MTBF drop from 32,895 years to 80 years? > > Even is the EnPhase's max output is 200 watts it's still more kWh/day then > the hobby system that spending most of it's time in float. I can see no > difference between one 72 cell module and two 36 cell module in series. > > Also it looks like there is unique connector coming off the AC side of the > module. How do I deal with that? > > Best and thanks in advance! > Travis Creswell > Ozark Energy Services > > > > No virus found in this outgoing message. > Checked by AVG. > Version: 7.5.557 / Virus Database: 270.11.43/2043 - Release Date: 4/6/2009 > 6:22 AM > > > _______________________________________________ > List sponsored by Home Power magazine > > List Address: [email protected] > > 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: [email protected] 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 No virus found in this incoming message. Checked by AVG. Version: 7.5.557 / Virus Database: 270.11.45/2045 - Release Date: 4/7/2009 6:41 AM No virus found in this outgoing message. Checked by AVG. Version: 7.5.557 / Virus Database: 270.11.47/2047 - Release Date: 4/8/2009 5:53 AM _______________________________________________ List sponsored by Home Power magazine List Address: [email protected] 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
