1.12 What variants of pole-changeable motors are applied?
A Dahlander motor is a two-speed motor that offers 1:2 switching (e.g., 2:4, 4:8, or 6:12, etc.). Motors that have Dahlander switching are designed for direct mains starting and are operated with only one voltage. Only one winding is used, which allows two different circuits in the terminal box for the individual speeds. Common for a Dahlander circuit are the two circuit types ∆/ΥΥ (delta/double star) and Y/YY (star/double star).
Motors with two separate windings
Motors with two separate windings offer the possibility of different speed ratios. Pole-changeable motors with two separate windings have different polarities, e.g., 4/6, 6/8, etc. The circuits are ∆/∆, Υ/Υ, and ∆/Υ for separate windings.