Preparing to wire my new shop & I am getting conflicting advice on my service entrance Cable.
I am installing a 100 Amp Sub Panel. Main panel is 270′ feet away.
It is a one-man shop so it is unlikely I will ever use 100 Amps at one time but I do want to do it properly.
I have been told & found on-line recommendations from #4 Aluminum to 2/0 Copper. What do you gentlemen think?
And why does every panel require it’s own ground? If I use a 4-conductor cable & ground the sub-panel & run a ground back to the main panel doesn’t that create a “ground loop”?
Thanks everyone….
Replies
Minimum code would be #3 copper or #1 aluminum. (310.16)
Ground loops are not an issue on power wiring. In fact we make them all the time. You establish a local ground electrode system at each building to be sure your electrical ground is at the same potential as the concrete floor you are sitting on. Earth is seldom actually "ground" in the "zero volts" sense. The more bonding/grounding you have the less "stray voltage" is a problem.
Thanks...
Did you account for volt drop?I get 1/0 or 3/0..
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A-holes. Hey every group has to have one. And I have been elected to be the one. I should make that my tagline.
I agree w/ Bill on this. #3 Cu would work if you were closer to the main panel. However, at 270', it would have too large a voltage drop if you're pulling decent current.
I agree with the statement in the original post. It would be hard to pull anything near 100a in a one man shop.
You are right if it only wood working shop.I am not sure, but I think that some welding stuff get up near there..
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A-holes. Hey every group has to have one. And I have been elected to be the one. I should make that my tagline.