I need some help sizing conductors for three phase. I have a 3 phase 600A service @480V that I want to feed a machine 450' away. Not sure the exact load yet but it will be close to that. The calculator that I have tells me the feeder cable should be 400MCM with #2 ground. Is this right and how can I double check this?
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Sizing conductors
- Thread starter catfaneng
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Strictly looking only at conductor rating, 600 A of load at 480 V would require TWO 350 kcmil copper PER PHASE and a #1 copper ground in EACH conduit plus an appropriately sized neutral, if required. Figure on two 3" conduits for that configuration. This voltage drop is not a concern and that ambient temperatures are not so high as to require derating.
But you also have to consider the upstream breaker rating since it must protect the conductor.
If you have a continuous load of 600 A, your breaker will need to be 1.25 x 600 A and this requires that your conductors be larger.
But maybe you need some consulting from a local EE familiar with these issues. It'll be cheaper than tearing it all out and replacing it after the local inspector red tags it.
But you also have to consider the upstream breaker rating since it must protect the conductor.
If you have a continuous load of 600 A, your breaker will need to be 1.25 x 600 A and this requires that your conductors be larger.
But maybe you need some consulting from a local EE familiar with these issues. It'll be cheaper than tearing it all out and replacing it after the local inspector red tags it.
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