Three-phase Induction motors draw six or more times rated current when started at rated voltage. Such high currents may pose serious problems for the motor and the electrical system when large motors are started. One way to reduce the starting current is to start the motor at reduced voltage. After looking at some of the considerations for full-voltage starting, we will consider several different methods of reduced-voltage starting.  This training module is ideal for new or experienced electricians and technicians that install, maintain, repair, or troubleshoot rotating machines.

Learning Objectives:

• Describe different types of motor starters.
• Explain why we use reduced voltage starting methods.
• Show the limitation of different starters.

Prerequisites:

Participants should have basic knowledge of basic electrical theory, magnetism and magnetic induction, AC motor theory and AC motor types.