Relays, Contactors, and Motor Starters 201

Relays, Contactors, and Motor Starters provides an overview of the primary components involved in electric motor control. Relays are electrical switches that control a circuit. When activated by current, a relay opens and closes a circuit to turn a larger current on or off. Contactors control current by conducting it through metal contacts that make or break electrical circuits. When combined with an overload relay, a contactor becomes a motor starter. Working with relays, contactors, and motor starters requires technicians to understand how to properly care for such devices and how to operate them effectively. After taking this class, users will be able to describe the design and function of common relays, contactors, and motor starters, as well as the applications for each device.