Danfoss VLT MCD 201

Danfoss Drives · DKDD.PB.551.A1.02 | 43
Two-Speed Motors: Are soft starters suitable for use
with two-speed motors?
Soft starters are suitable for use with Dahlander and dual winding
motors, provided that separate motor protection is used for both
low and high speed operation.
Dual-winding motors have one shaft with two separate pole
congurations (e.g. 4 pole and 8 pole), providing two dierent
speeds. The speed is selected using external contactors (AC3
rated).
Dahlander motors are often used for two-speed compressor or
fan applications. The motor windings are externally congured
using contactors for high speed (dual star) and low speed (delta)
operation.
MCD 201 soft starters are designed for use with external
motor protection devices and are ideal for two-speed
motor applications. MCD 202 soft starters have motor
protection built in and are less suitable for two-speed
applications.