<html><head><base href="x-msg://78/"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; ">Hi Nick,<div><br></div><div>You bring up a good point that Enphase should address more clearly.</div><div>However, I think the math should be done section by section to accurately account for the wire loss and not the total combined amps for the entire length.</div><div>If the loss's are too high then reducing the number in each string to an acceptable wire loss would be my recommendation.</div><div><br></div><div><br></div><div><div><div>On Jun 11, 2010, at 12:14 AM, Nick Soleil wrote:</div><br class="Apple-interchange-newline"><blockquote type="cite"><span class="Apple-style-span" style="border-collapse: separate; font-family: Helvetica; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-border-horizontal-spacing: 0px; -webkit-border-vertical-spacing: 0px; -webkit-text-decorations-in-effect: none; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; font-size: medium; "><div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; font-family: arial, helvetica, sans-serif; font-size: 12pt; ">Hello wrenches and Marv:<br> How many Enphase inverters do you put on a single parallel string? The Enphase manual allows for up to 15, but I have found that a single string of 15 can have very high voltage rise on the AC wiring. Up to 1.5% loss just on the Enphase cables, and that does not take into account resistance at the plug connectors or any home-run wiring.<br> 15 inverters x 190 watts = 2850 watts<br> 2850 watts / 240 Volts = 11.875 Amps (however at the beginning of the string it is 0 Amps)<br> Average Amps on the Enphase cables is 11.875 / 2 = 5.9375 Amps<br> length of contacts + internal wiring = ~6'<br> Total Enphase cabling length (6' x 15 inverters) = ~90'<br> 5.9375 Amps @ 240 V running 90' on #14 AWG CU = 1.4% loss<br>It is pretty hard to design for 1.5% voltage drop if you have to size for 0% loss on your wiring! I hope Enphase will increase the size of the wire in their cables soon. Have you experienced issues with micro-inverters shutting off due to high AC voltages? <span class="Apple-converted-space"> </span><br><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; "> </div>Nick Soleil<br>Project Manager<br>Advanced Alternative Energy Solutions, LLC<br>PO Box 657<br>Petaluma, CA 94953<br>Cell: 707-321-2937<br>Office: 707-789-9537<br>Fax: 707-769-9037<div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; "><br></div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; font-family: arial, helvetica, sans-serif; font-size: 12pt; "><br><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; font-family: 'times new roman', 'new york', times, serif; font-size: 12pt; "><font face="Tahoma" size="2"><hr size="1"><b><span style="font-weight: bold; ">From:</span></b><span class="Apple-converted-space"> </span>i2p <<a href="mailto:i2p@aol.com">i2p@aol.com</a>><br><b><span style="font-weight: bold; ">To:</span></b><span class="Apple-converted-space"> </span>RE-wrenches <<a href="mailto:re-wrenches@lists.re-wrenches.org">re-wrenches@lists.re-wrenches.org</a>><br><b><span style="font-weight: bold; ">Sent:</span></b><span class="Apple-converted-space"> </span>Thu, June 10, 2010 4:50:47 PM<br><b><span style="font-weight: bold; ">Subject:</span></b><span class="Apple-converted-space"> </span>Re: [RE-wrenches] Real world PV production<br></font><br><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; "><span class="Apple-style-span"><br></span></div><div id="replyPrefaceElement" style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; ">On Jun 10, 2010, at 7:57:53 AM, "Kelly Keilwitz, Whidbey Sun & Wind" <<a href="mailto:kelly@whidbeysunwind.com">kelly@whidbeysunwind.com</a>> wrote:</div><br><blockquote style="padding-left: 5px; margin-left: 5px; border-left-width: 2px; border-left-style: solid; border-left-color: blue; color: blue; "><span class="Apple-style-span" style="border-collapse: separate; font-family: Helvetica; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; font-size: medium; ">PV Watts VASTLY underestimate PV production in our area.</span></blockquote><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; "><span class="Apple-style-span">PV Watts underestimates in Central Ca too.<div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; "><span class="Apple-style-span"><br></span></div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; "><span class="Apple-style-span">Don</span></div></span></div><div class="aol_ad_footer" id="u9AF4D3CAE2F14AA2984631575C953336" style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; "></div></div></div></div><br>_______________________________________________<br>List sponsored by Home Power magazine<br><br>List Address:<span class="Apple-converted-space"> </span><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">http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org</a><br><br>List-Archive:<span class="Apple-converted-space"> </span><a href="http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org">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">www.re-wrenches.org/etiquette.htm</a><br><br>Check out participant bios:<br><a href="http://www.members.re-wrenches.org">www.members.re-wrenches.org</a><br><br></div></span></blockquote></div><br></div></body></html>