I have a 1250 HP DC motor application at an elevation of 7,500ft. Because of the elevation, the DC drive has to be derated (for cooling) which bumps the drive size up to 1500HP. The 1250 HP drive is rated for 2000A AC input while the 1500HP drive is rated 2450A AC input. Per 430.122(A), I would have to size the conductors at 125% of 2450A. From an engineering perspective, I see this as a waste of money since the drive will not require that ampacity and will operate safely if designed as if I were using the 1250HP drive. Have I overlooked another relevant section of the code that would override this and/or is there a legal way around this code requirement?
Feeder/Branch circuit wire sizing for drive systems
- Thread starter steve8440
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