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Not necessarily. I believe on newer locos the air compressor has a separate motor that is run from the system voltage. Hence the "Whoop" sound when the compressor motor starts.

BN 4246

Rail buff.
what is the difference between 260,000 to 282,000 pounds in these locomotives?
It's highly likely that this is ballast weight, used to improve adhesion between drive wheels and the rail. I'd also concede that some of that weight could be equipment differences. But that's 22,000 pounds, 11 tons. I doubt an HEP generator weighs that much. At most a couple of tons. So, the weight difference is probably ballast to improve adhesion. Also, in amost all older EMD locomotives up to and including the SD70ACe, the air compressor is drive-shaft driven off of the main engine. It is a separate component. The traction alternator (incorrectly called a generator) is also a separate component, which bolts directly to the flywheel and block of the main engine.
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