Real Answers 2009: December's Problem

Oct. 7, 2009

We build some pretty basic machines that have only limited need for variable speed control of 240/480 Vac motors from 5 to 20 hp. That's going to change as we expand the machines' capabilities and design them to integrate into systems. We're arguing about whether to switch from full-voltage starters to either VFDs or soft starters. We think we could save energy costs with VFDs because we sometimes run at faster speeds than we need to, but that's not a big deal at the moment. Soft starts would clearly be easier on the system at startup. Cost can't be ignored.

We build some pretty basic machines that have only limited need for variable speed control of 240/480 Vac motors from 5 to 20 hp. That's going to change as we expand the machines' capabilities and design them to integrate into systems. We're arguing about whether to switch from full-voltage starters to either VFDs or soft starters. We think we could save energy costs with VFDs because we sometimes run at faster speeds than we need to, but that's not a big deal at the moment. Soft starts would clearly be easier on the system at startup. Cost can't be ignored.

Send us your comments, suggestions or solutions for this problem. We'll include it in the December '09 issue and post it on ControlDesign.com. Send visuals if you'd like-a sketch is fine. Email us at [email protected]. Please include your company, location and title in the response.

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