Soft starter ratings

There are many different ways in which designers determine the ratings that they will apply to soft starters. This results in a wide disparity in the reliability of products under equal conditions and leads to a lot of confusion for the end user. There are some standards, such as IEC60947-4-2 that describe how soft starters will be rated, but these do not cover how the ratings should be derived. I have a small discussion at : and I am interested in any ideas or information that you have.

Best regards,


Mark Empson