Christopher, OCV calculation 37.0v + (37 x .0035 x 56) x 12 = 531 volts Maximum system voltage
Schuco MPE 230 PS09 modules 29.81Vmp, 7.69 Imp, 37.0 Voc, 8.43 Isc 3 strings of 12 for 8,280 Watts into SB800US 240v inverter SMA Sunny Design: - nominal power ratio 104% good - String MPP Voltage at 15C 370 V good - String MPP Voltage at 50C 326 V good - String MPP Voltage at 70C 301 V OK conditionally says OK "as long as grid voltage is not too high". I have an almost identically designed system (modules are 225W not 230W) in for one year with no problems. Admittedly, grid voltage would be a variable. Note: Hot temperatures have not been an issue here since system was installed. Dusk and dawn, when problem occurs, we've been seeing temps from 25 to 55 degrees F. Dave -----Original Message----- From: re-wrenches-boun...@lists.re-wrenches.org [mailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of Christopher Warfel Sent: Friday, October 28, 2011 9:32 AM To: RE-wrenches Subject: [!! SPAM] Re: [RE-wrenches] SMA electrical noise? Check array open circuit voltage calculation? On 10/28/2011 8:46 AM, Dave Palumbo wrote: > > Wrenches, > > This is a new one on me. Any ideas of what may be happening? > > In a follow up she said it happens every day. System was installed two > months ago. SB8000US inverter 8.28kW array. > > << Dave > > We are experiencing electrical noise at dawn and dusk. The power back > ups for our computers start beeping, going off and on, and finally > causing the computers to shut down. This is probably not good for the > computers. Is this something you are aware of in these systems? > > Can you give us some advice or perhaps come over to check into it? > > Like I said, at dawn and dusk, just when the sun is changing intensity. >> > > David Palumbo > > Independent Power LLC > > 462 Solar Way Drive > > Hyde Park, VT 05655** > > */www.independentpowerllc.com /* > > NABCEP Certified PV Installer > > Vermont Solar Partner > > 23 Years Experience, (802) 888-7194 > > > _______________________________________________ > 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 > > -- Christopher Warfel, P.E. ENTECH Engineering, Inc. Energy Utilization Experts (401)466-8978 The information contained within this communication shall be considered confidential and shall not be retransmitted without knowledge of the sender. Please contact us if this email reached you in error. Thank you. _______________________________________________ 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 _______________________________________________ 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