Load transfer strategies for machine and other inrush loads

Changes in the profile of critical loads challenge the traditional concept of load transfer, the double throw switch. Concerns have been raised over the suitability of this concept for reliable transfer of running motors and other inrush loads. A position is taken that these loads must be shut down for transfer between live sources to avoid power system disturbances and equipment damage. Such actions are counterproductive and disruptive to facility operations. This paper presents the results of an investigation into the characteristics of inrush electrical loads in a load transfer strategy. It verifies the validity of the traditional transfer concept.