I have been tasked with re-building a panel that has three ABB drives. It's all pretty straight forward, except for one detail that has me rather perplexed. If you look at the drives in the attached image, you will notice the wires and fuses between the two drives' DC brake terminals. You will also notice that the drive on the right does not have input power connected. Is the 50 HP drive somehow supposed to be powering the 20 HP drive via the DC brake circuit? I have never heard of such a thing. The actual wiring in the panel is done according to the drawing. Any speculation as to what is intended here?
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