pole-changing control

pole-changing control

[′pōl ¦chānj·iŋ kən‚trōl]
(electromagnetism)
A method of obtaining two or more running speeds of a three-phase motor by making changes in the number of magnetic poles, usually by making changes in the coil connections at the winding terminals.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.