[RE-wrenches] Parallel wire runs to increase size

[Dave Click]

310.4(B) Conductor Characteristics. The paralleled conductors in each 
phase, polarity, neutral, grounded circuit conductor, or equipment 
grounding conductor shall comply with all of the following:
(1) 	Be the same length
(2) 	Have the same conductor material
(3) 	Be the same size in circular mil area
(4) 	Have the same insulation type
(5) 	Be terminated in the same manner

Jason Szumlanski wrote:
> Nick,
>
> Can you cite a code section that supports this. (not challenging you –
> it makes sense and I agree)
>
> I have been wondering about SMA’s recommendation to parallel two 1/0
> cables for a Sunny Island. If the wire sizes and lengths are identical,
> is this acceptable?
>
> Jason Szumlanski
>
> Fafco Solar
>
> *From:*re-wrenches-bounces at lists.re-wrenches.org
> [mailto:re-wrenches-bounces at lists.re-wrenches.org] *On Behalf Of *Nick
> Soleil
> *Sent:* Wednesday, February 02, 2011 12:05 PM
> *To:* RE-wrenches
> *Subject:* Re: [RE-wrenches] Parallel wire runs to increase size
>
> You shouldn't parallel wiring that way. That is not acceptable by code,
> and it is unnecessary. If the #10 is not sufficient just replace it. Due
> to the fact that the larger wiring has much less resistance, most if not
> all of the current will flow on the larger wires.
>
> Nick Soleil
> Project Manager
> Advanced Alternative Energy Solutions, LLC
> PO Box 657
> Petaluma, CA 94953
> Cell: 707-321-2937
> Office: 707-789-9537
> Fax: 707-769-9037
>
> ------------------------------------------------------------------------
>
> *From:*"Starlight Solar, Larry Crutcher" <larry at starlightsolar.com>
> *To:* RE-wrenches <re-wrenches at lists.re-wrenches.org>
> *Sent:* Wed, February 2, 2011 8:00:07 AM
> *Subject:* [RE-wrenches] Parallel wire runs to increase size
>
> Wrenches,
>
> Some of our business involves repairing poor PV solar installations on
> recreational vehicles. So often we wind up installing a roof junction
> box and running a second PV to controller wire and then replacing the
> controller to battery wire size. For instance, we may find a 10 gauge
> wire run to the controller. We then add #8, #6, #4 or even 2 gauge and
> parallel to the #10 depending on power and distance of the run. My
> question: Is there a calculator or chart that will tell me what the
> combination of any two wire sizes equate to? example: #10 + #4 = X
>
> Thanks.
>
> Larry Crutcher
> Starlight Solar Power Systems <http://www.starlightsolar.com>
> /powered by //*S*//*TARLIGHT*/™
>
>
>
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