Lets say I've done a load calculation and determine that the load is under 380A and thus I can use a 500MCM cable. Can I use this 500MCM cable on a 400A breaker since I can use the "next size up rule"?
The way I understand it though I would not be able to use the 500MCM cable on a 450A breaker since this 450A brekaer is not the next size up. Is this correct?
So if I had a 450A breaker I would need to use a 600MCM cable at minimum. Is this correct?
When a breaker is upsized for transformer inrush then must you still also increase the cable size so that the cable size is protected by the "next size up" rule as well?
The way I understand it though I would not be able to use the 500MCM cable on a 450A breaker since this 450A brekaer is not the next size up. Is this correct?
So if I had a 450A breaker I would need to use a 600MCM cable at minimum. Is this correct?
When a breaker is upsized for transformer inrush then must you still also increase the cable size so that the cable size is protected by the "next size up" rule as well?