[RE-wrenches] Long MC Cable Mid String

[Darryl Thayer]

Yes, Voltage drop is current times resistance, so the total voltage drop is the total resistance times the current flowing. the total resistance is the some of the resistances, which is the same as the some of the voltage drops.  
Darr5yl  


--- On Wed, 4/22/09, Drake Chamberlin <drake.chamberlin at redwoodalliance.org> wrote:

> From: Drake Chamberlin <drake.chamberlin at redwoodalliance.org>
> Subject: Re: [RE-wrenches] Long MC Cable Mid String
> To: dkatz at aeesolar.com, "RE-wrenches" <re-wrenches at lists.re-wrenches.org>
> Date: Wednesday, April 22, 2009, 9:15 AM
> 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
> >><http://www.independentpowerllc.com>www.independentpowerllc.com
> >>
> >>
> >>
> >>
> >>
> >>
> >>
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> Drake Chamberlin
> Athens Electric
> OH License 44810
> CO License 3773
> 740-448-7328
> 740-856-9648 
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