Motorstartbrytere

Motorstartbrytere, also known as motor starters, are electrical devices used to control electric motors. Their primary function is to start and stop a motor safely and efficiently. A basic motor starter typically consists of a contactor and an overload relay. The contactor is an electrically operated switch that connects the motor to the power supply, while the overload relay protects the motor from damage due to excessive current.

Motor starters perform several crucial roles. They provide a means to safely energize and de-energize the motor, preventing electrical shock and equipment damage. They also offer overload protection, tripping the circuit if the motor draws more current than it is designed for, which can overheat and damage the motor windings. Some motor starters also include under-voltage protection, which disconnects the motor if the supply voltage drops too low, preventing it from stalling or overheating.

There are various types of motor starters, each suited for different applications. Simple direct-on-line (DOL) starters are used for smaller motors and provide full line voltage to the motor upon starting. Reduced voltage starters, such as star-delta, autotransformer, or soft starters, are employed for larger motors to limit the inrush current during startup. This is important as high inrush currents can cause voltage sags in the power system and mechanical stress on the motor and connected equipment. The choice of starter depends on factors like motor size, power supply capacity, and the specific requirements of the application.