<html><head><meta http-equiv="Content-Type" content="text/html; charset=utf-8"></head><body><div><div style="font-family: Calibri,sans-serif; font-size: 11pt;">You would want to confirm hot temp PV circuit values with chosen Vdrop to ensure the irrelevant value doesn't drop you out of the inverters' operational limit, however.<br><br>Sincerely,<br>Glenn Burt<br>Sent from my 'smart' phone so please excuse grammar and typos.</div></div><div dir="ltr"><hr><span style="font-family: Calibri,sans-serif; font-size: 11pt; font-weight: bold;">From: </span><span style="font-family: Calibri,sans-serif; font-size: 11pt;"><a href="mailto:cometenergysystems@gmail.com">Chris Mason</a></span><br><span style="font-family: Calibri,sans-serif; font-size: 11pt; font-weight: bold;">Sent: </span><span style="font-family: Calibri,sans-serif; font-size: 11pt;">7/25/2015 15:20</span><br><span style="font-family: Calibri,sans-serif; font-size: 11pt; font-weight: bold;">To: </span><span style="font-family: Calibri,sans-serif; font-size: 11pt;"><a href="mailto:re-wrenches@lists.re-wrenches.org">RE-wrenches</a></span><br><span style="font-family: Calibri,sans-serif; font-size: 11pt; font-weight: bold;">Subject: </span><span style="font-family: Calibri,sans-serif; font-size: 11pt;">Re: [RE-wrenches] DC conductor line loss numbers</span><br><br></div><div dir="ltr">It should be noted that the NEC recommendations for feeder circuits are to do with acceptable voltages at the load, i.e., you do not want your 208V equipment running on 200V. PV circuits are not feeder circuits, voltage drop is irrelevant. Power loss may be relevant, but only in terms of economic value. If it is preferable to add more PV and lose 10% of the power, as long as there are no issues of heat and potential fire, why shouldn't you be able to make that decision? As PV gets cheaper, replacing cables costing $10,000 to save $10 a year does not make sense. The NEC rules on voltage drop were never designed for PV source circuits.</div><div class="gmail_extra"><br><div class="gmail_quote">On Fri, Jul 24, 2015 at 11:52 PM, Jerry Shafer <span dir="ltr"><<a href="mailto:jerrysgarage01@gmail.com" target="_blank">jerrysgarage01@gmail.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin: 0px 0px 0px 0.8ex; padding-left: 1ex; border-left-color: rgb(204, 204, 204); border-left-width: 1px; border-left-style: solid;"><div dir="ltr"><div>Wrenches<br>I have 3 engineering firms and one in-house engineer that only use 1% because in the NEC it is stated as a suggestion and not a requirement but they take this as a must not exceed instead, <br></div>I cant change CC as it will be remotely monitored via the Outback connection, the Engineers refuse to make any changes to the 1% and still stamp the drawings. This is what I have found in my research it came from Mike Holt<br> <br><p>Contrary to common belief, the NEC generally doesn't require you to
size conductors to accommodate voltage drop. It merely suggests in the
Fine Print Notes to 210.19(A), 215.2(A)(4), 230.31(C), and 310.15(A)(1)
that you adjust for voltage drop when sizing conductors. It's important
for you to remember that Fine Print Notes are recommendations, not
requirements [90.5(C)].</p> <p>The NEC
recommends that the maximum combined voltage drop for both the feeder
and branch circuit shouldn't exceed 5%, and the maximum on the feeder or
branch circuit shouldn't exceed 3%. This recommendation is a performance issue, not a safety issue.</p><p>Jerry<br></p></div><div class="gmail_extra"><br><div class="gmail_quote"><div><div class="h5">On Wed, Jul 22, 2015 at 11:28 AM, Starlight Solar Power Systems <span dir="ltr"><<a href="mailto:larry@starlightsolar.com" target="_blank">larry@starlightsolar.com</a>></span> wrote:<br></div></div><blockquote class="gmail_quote" style="margin: 0px 0px 0px 0.8ex; padding-left: 1ex; border-left-color: rgb(204, 204, 204); border-left-width: 1px; border-left-style: solid;"><div><div class="h5"><div style="-ms-word-wrap: break-word;">Jerry,<div><br></div><div>A long distance wire run is practical now days using a high voltage controller. Have a look at Schneider and Morningstar 600Vdc controllers. Not sure what you mean "by nothing can be changed but wire size” but you will have to rewire the strings into series and protect the wire run.</div><div><div><div style="color: rgb(0, 0, 0); text-transform: none; text-indent: 0px; letter-spacing: normal; word-spacing: 0px; white-space: normal; -ms-word-wrap: break-word;"><div style="color: rgb(0, 0, 0); text-transform: none; text-indent: 0px; letter-spacing: normal; word-spacing: 0px; white-space: normal; -ms-word-wrap: break-word;"><div style="color: rgb(0, 0, 0); text-transform: none; line-height: normal; text-indent: 0px; letter-spacing: normal; font-family: Helvetica; font-style: normal; font-variant: normal; font-weight: normal; word-spacing: 0px; white-space: normal; -ms-word-wrap: break-word;"><br>Larry Crutcher<span><font color="#888888"><br>Starlight Solar Power Systems<br></font></span></div><div style="color: rgb(0, 0, 0); text-transform: none; line-height: normal; text-indent: 0px; letter-spacing: normal; font-family: Helvetica; font-style: normal; font-variant: normal; font-weight: normal; word-spacing: 0px; white-space: normal; -ms-word-wrap: break-word;"><br><br></div></div></div>
</div>
<br><div><div><div><div>On Jul 22, 2015, at 10:37 AM, Jerry Shafer <<a href="mailto:jerrysgarage01@gmail.com" target="_blank">jerrysgarage01@gmail.com</a>> wrote:</div><br></div></div><div><div><div><div dir="ltr"><div><div><div><div>Wrenches<br></div>Some time back there was discussion on the conductor size and efficiency rating requirement for long DC runs.<br></div>What I am looking at is this, 400 feet of MCM 400 to keep the line loss at or below 1% per NEC code for an off grid application, cost vs return is not acceptable. 2/0 is less than 2.5% and the cost is far less. Specs are 4 strings of 3, 250 watt modules feeding one Outback FM 80 charge controller. There are lots of things I can do like SMA instread, or 200 VDC charge controller but nothing can be changed except the wire gauge. Does anyone recall a thread with this topic.<br><br></div>thoughts ??<br></div>Jerry<br></div></div></div>
________________________<br><br></div></div><br></div></div><br></div></div><span>_______________________________________________<br>
List sponsored by Redwood Alliance<br>
<br></span>
List Address: <a href="mailto:RE-wrenches@lists.re-wrenches.org" target="_blank">RE-wrenches@lists.re-wrenches.org</a><span><br>
<br>
Change listserver email address & settings:<br>
<a href="http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org" target="_blank" rel="noreferrer">http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org</a><br>
<br>
List-Archive: <a href="http://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/maillist.html" target="_blank" rel="noreferrer">http://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/maillist.html</a><br>
<br>
List rules & etiquette:<br>
<a href="http://www.re-wrenches.org/etiquette.htm" target="_blank" rel="noreferrer">www.re-wrenches.org/etiquette.htm</a><br>
<br>
Check out or update participant bios:<br>
<a href="http://www.members.re-wrenches.org" target="_blank" rel="noreferrer">www.members.re-wrenches.org</a><br>
<br>
<br></span></blockquote></div><br></div>
<br>_______________________________________________<br>
List sponsored by Redwood Alliance<br>
<br>
List Address: <a href="mailto:RE-wrenches@lists.re-wrenches.org">RE-wrenches@lists.re-wrenches.org</a><br>
<br>
Change listserver email address & settings:<br>
<a href="http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org" target="_blank" rel="noreferrer">http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org</a><br>
<br>
List-Archive: <a href="http://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/maillist.html" target="_blank" rel="noreferrer">http://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/maillist.html</a><br>
<br>
List rules & etiquette:<br>
<a href="http://www.re-wrenches.org/etiquette.htm" target="_blank" rel="noreferrer">www.re-wrenches.org/etiquette.htm</a><br>
<br>
Check out or update participant bios:<br>
<a href="http://www.members.re-wrenches.org" target="_blank" rel="noreferrer">www.members.re-wrenches.org</a><br>
<br>
<br></blockquote></div><br><br clear="all"><div><br></div>-- <br><div class="gmail_signature"><div dir="ltr">Chris Mason<div><div style="color: rgb(136, 136, 136);"><span style="font-size: 13px;">NABCEP Certified Solar PV Installer™</span></div><div style="color: rgb(136, 136, 136);"><span style="color: rgb(34, 34, 34);">Solar Design Engineer</span></div><div style="color: rgb(136, 136, 136);"><span style="font-size: 13px;">Generac Generators Industrial technician</span></div></div><div style="color: rgb(136, 136, 136);"><span style="font-size: 13px;"><br></span></div><div><a href="http://www.cometenergysystems.com" target="_blank">www.cometsolar.com</a></div></div></div></div><br><div>[The entire original message is not included.]</div></body></html>