I'm almost apologetic (I'm never apologetic but I thought it would be politic to claim I almost am...) to begin yet another thread on wiring, but here we go with my own situation.
What's slightly different is that the run I am considering dealing with is phenomenally short. We're looking at hardly two feet from the breaker location on the main service panel through to a perfect site for an HPWC on a garage interior wall. So I upped that by 50 percent to err on the safe side.
As follows: from the ampacity tables I have then, under the conditions of:
* 240 V single-phase
* Cu wire
* 3' one-way distance
* 80 amps continuous/maximum draw
we will get voltage drops and nominal end voltage (given perfect 240V starting conditions) of:
3ga 0.04% or 239.903V
4ga 0.05% or 239.877V
6ga 0.08% or 239.805V
Further consideration: the cross-sectional diameter of the three gauges differ as follows:
6 ga = unity
4 ga: 59% bigger than 6 ga
3 ga: 100% bigger than 6ga; 26% larger than 4 ga
So......can anyone come up with a reasonable answer as to why I shouldn't make use of the far, far more tractable 6 ga than the alternatives?
What's slightly different is that the run I am considering dealing with is phenomenally short. We're looking at hardly two feet from the breaker location on the main service panel through to a perfect site for an HPWC on a garage interior wall. So I upped that by 50 percent to err on the safe side.
As follows: from the ampacity tables I have then, under the conditions of:
* 240 V single-phase
* Cu wire
* 3' one-way distance
* 80 amps continuous/maximum draw
we will get voltage drops and nominal end voltage (given perfect 240V starting conditions) of:
3ga 0.04% or 239.903V
4ga 0.05% or 239.877V
6ga 0.08% or 239.805V
Further consideration: the cross-sectional diameter of the three gauges differ as follows:
6 ga = unity
4 ga: 59% bigger than 6 ga
3 ga: 100% bigger than 6ga; 26% larger than 4 ga
So......can anyone come up with a reasonable answer as to why I shouldn't make use of the far, far more tractable 6 ga than the alternatives?