These versions are primarily used as speed controllers. They are beneficial for upstream control applications or if the device is combined with control modules from the ZIEHL-ABEGG UNIcon product family.

Depending on the device version, speeds can be pre-set. They can also be set to second stage operation with external switchover, or implemented via an external potentiometer.

The Acontrol voltage control devices also provide an option to control based on temperature or pressure (for example, refrigerant pressure in cooling equipment).