Quite simply, you don't CARE about the voltage drop as volts. What you care about is the PERCENTAGE. Dropping 1 volt in a 12 volt system is not acceptable. Dropping 10 volts in a 500 volt system is .2 percent.
.................................................................................................. Northern Arizona Wind & Sun - Electricity From The Sun Since 1979 Solar Discussion Forum: http://www.wind-sun.com/ForumVB/ .................................................................................................. ----- Original Message ----- From: Drake Chamberlin To: dk...@aeesolar.com ; RE-wrenches Sent: Wednesday, April 22, 2009 7:15 AM Subject: Re: [RE-wrenches] Long MC Cable Mid String I have scratched my head on this one before, because it seems that two terminals bonded together by a wire are essentially the same terminal. The theoretical voltage difference on a terminal is zero. How do we figure a voltage drop on a wire that has near zero volt potential between the ends of the wire. Can we really use the voltage of the entire array to figure the drop on an interconnect between two modules? If so, why can we do this? Thanks, Drake At 07:49 PM 4/21/2009, you wrote: David, There will be less than a 1 volt drop in 36 feet of 10 AWG at the 11 amps you get from the Evergreen modules. I don't think anyone will notice. David David Katz David Palumbo wrote: Does the following series string wiring cause a problem? With (18) Evergreen ES-A 205's (low voltage modules 18.4Vmp) in series feeding a grid tie inverter with a long series connector in the middle of the string. (2) Top Of Pole 9 module mounts with the series connection from module #8 on the first pole to module #9 on the second pole. This MC cable connection would be, about, 36 feet in length to go 10' down the pole below grade 18" for 13' and back up the second pole 10' (in conduit all the way) . Will this extra long series wire cause problems? I could use other modules of course but that would raise the cost per watt by 70 cents. Dave David Palumbo, President Independent Power LLC 462 Solar Way Drive Hyde Park, VT 05655 NABCEP Certified www.independentpowerllc.com _______________________________________________ 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 Drake Chamberlin Athens Electric OH License 44810 CO License 3773 740-448-7328 740-856-9648 ------------------------------------------------------------------------------ _______________________________________________ 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
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