What device is used before a motor to allow electricity to flow to the motor?

The device that is used before a motor to allow electricity to flow to the motor is a motor starter. This component not only facilitates the initial flow of electricity to the motor when it is started but also provides essential protective features such as overload protection and control circuit integration.

When a motor is powered on, it needs a controlled start-up process to prevent damage from inrush currents, which can occur when the motor is first energized. The motor starter achieves this by providing a means to gradually apply power to the motor, often using techniques such as reducing voltage during startup or incorporating soft starter features.

While contactors and relays are also involved in motor control, they are not specifically designed to handle the startup and protective functions that a motor starter provides. A contactor can be part of a motor starter assembly, serving as an electromagnetic switch to control the power flow, and a relay typically serves a general control or signaling function. A transformer, on the other hand, is used to change the voltage level and is not directly involved in starting motors but rather in supplying power to them at the appropriate voltage levels.