[RE-wrenches] Parallel Wire combining

[boB at midnitesolar.com]

The "area" of the conductor will be 3 times and you would think that the 
NEC Ampacity would also be 3 times
that of one conductor.   But one LARGE conductor with the same area 
might not be as high as you think
because of insulation.  I would think that ampacity of 3 cables in 
parallel would be 3 times.  But probably
not when you take a single cable of the 3X area out of the NEC table.  
(I haven't looked at this to verify)

Also,  Larry,  325 AWG 750 AWG (gauge) wire is a bit too small for this, 
don't you think ?

I know...  You mean circular mils...
boB


On 12/2/2014 1:49 PM, Larry wrote:
> That's the part that is throwing me off. If I have 3 times the 
> circular mil and compare that to a single conductor of similar 
> circular mil, how do I have 3 times the ampacity? These are very 
> different numbers.
>
> Example: 1/0 @ 90c is 170 amps x 3 = 510 amps. 510A is what a 
> conductor just over 750 AWG will carry. The circular mils of 3 1/0 
> cables is only 325,050 or a 325 AWG cable which would be rated at 
> about 330 amps.
>
> So, is it 510 amps (3x the ampacity) or 330 amps (3x circular mil)? 
> And, more importantly, why?
>
> Larry
>
> On 12/2/14 11:14 AM, Bill Turberville wrote:
>>
>> I am sorry.  Bad fingers.  Three times the ampacity under the same 
>> conditions.
>>
>> *From:*RE-wrenches [mailto:re-wrenches-bounces at lists.re-wrenches.org 
>> <mailto:re-wrenches-bounces at lists.re-wrenches.org>] *On Behalf Of *Larry
>> *Sent:* Tuesday, December 02, 2014 12:09 PM
>> *To:* RE-wrenches
>> *Subject:* Re: [RE-wrenches] Parallel Wire combining
>>
>> OK, let's use 1/0 for the example. 108,350 x 3 = 325,050. Do I now 
>> have a cable between 300 and 350 AWG?
>>
>> Thank you,
>>   
>> Larry
>>
>

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