<html><head><meta http-equiv="Content-Type" content="text/html charset=us-ascii"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;"><div>Richard,</div><div><br></div><div><b>The system configuration is:</b></div><div>Approx 24.7kW of modules connected to:</div><div><span class="Apple-tab-span" style="white-space:pre"> </span>2 x 9kW Sunnyboys</div><div><span class="Apple-tab-span" style="white-space:pre"> </span>1 x 5kW Sunnyboys</div><div>Plus</div><div>4 x 6kW sunnyislands, with</div><div>2 Parallel 48V Strings of (12 x 4V Surrettes ) using 350MCM cable</div><div><br></div><div><b>Wire</b></div><div>The wire is about 1000 feet long 350 MCM in a "twisted" bundle to this outbuilding</div><div><br></div><div><b>Conditions</b></div><div>The conditions were during the day with full sun, so during the test there is approx. 47kW of available inverter pointed at only >15 amps (120V) of load(!).</div><div>The steady state conditions was a few LED lights, maybe 60 watts worth, plus a handful of vampire loads, maybe 100-200 watts total. When a pure resistance load, like a 1000W curling iron was turned on the lights would flicker.</div><div><br></div><div>Since the lights flickered from a resistive load, but didn't stay dim, I assumed it was from a reactive-phase issues due to the transient turn-on - screwing with the LED dimmer circuits which are already doing a bit of magic to turn TRIAC waveforms into a DC constant current.</div><div><br></div><div><br></div><div apple-content-edited="true">
<span class="Apple-style-span" style="border-collapse: separate; border-spacing: 0px;"><div style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><span style="font-size: 11px; ">thanks,<br><br>Troy Harvey<br>---------------------<br>Principal Engineer<br>Heliocentric<br>801-453-9434<br><a href="mailto:taharvey@heliocentric.org">taharvey@heliocentric.org</a><br></span><br><br></div></span>
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<br><div><div>On Feb 3, 2014, at 8:33 AM, Richard L Ratico <<a href="mailto:Richard.L.Ratico@VALLEY.NET">Richard.L.Ratico@VALLEY.NET</a>> wrote:</div><br class="Apple-interchange-newline"><blockquote type="cite">Hi Troy,<br><br>I'm assuming this is off grid. Could you please provide details for the system<br>(inverters, batteries, etc.). <br>A single, sudden, 20 amp load is not necessarily small relative to the size of<br>the system. Is the load 120V or 240 V?<br><br>Dick Ratico<br>Solarwind Electric<br><br><br>--- You wrote:<br>On Sun, Feb 2, 2014 at 4:39 PM, Troy Harvey <<a href="mailto:taharvey@heliocentric.org">taharvey@heliocentric.org</a>>wrote:<br><br><blockquote type="cite"><br><br>We've got a PV system that has long lines from the inverters to the house<br>(1000 ft or so). While the wires are properly sized (2x350MCMs), it<br>inherently has a lot of inductance due to the line-length. What We are<br>noticing is that dimmable LED lights flicker anytime a new load turned on,<br>even if that load is purely resistive and the overall current draw is small<br>(20 amps or so). What I "think" is happening is the LED dimmer circuits get<br>their cue from phase delays, and that the inductance of the line length<br>causes some phase jitter everytime a load is applied - thus causing flicker.<br><br>Has anyone dealt with this issue successfully (other than switching<br>to incandescent lights)? Would a static capacitor bank at the house do the<br>trick, or do we need some type of active PFC? And if static did you have<br>any issues with constant power draw from the capacitors?<br><br><br><br>Troy Harvey<br>---------------------<br>Heliocentric<br><br></blockquote>--- end of quote ---<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>Change email address & settings:<br><a href="http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org">http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org</a><br><br>List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org<br><br>List rules & etiquette:<br>www.re-wrenches.org/etiquette.htm<br><br>Check out participant bios:<br>www.members.re-wrenches.org<br><br></blockquote></div><br></body></html>