How does an electric motor starter work?
1 Answer
An electric motor starter is a device used to start, stop, and control the operation of an electric motor. It is designed to protect the motor from overloading and damage while providing a convenient and safe way to start and stop the motor's operation. There are different types of electric motor starters, but one of the most common types is the magnetic motor starter. Here's how it works:
Magnetic Contactor: The heart of the magnetic motor starter is a component called the magnetic contactor. It consists of a coil and a set of contacts. The coil is an electromagnetic winding that, when energized, generates a magnetic field.
Start Button: To start the motor, a "start" button is pressed. This action sends an electrical signal to the coil of the magnetic contactor.
Magnetic Field Generation: When the coil receives the electrical signal, it becomes energized and creates a magnetic field around it.
Closing of Main Contacts: The magnetic field attracts a movable iron core within the contactor. This movement causes the main contacts (large electrical switches) to close, completing the circuit between the power source and the motor.
Power to Motor: With the main contacts closed, electrical power from the source flows through the contactor to the motor, causing it to start rotating.
Overload Protection: Additionally, motor starters often have overload protection built in. These devices monitor the current flowing through the motor. If the current exceeds a set limit, typically due to an overload or fault, the overload protection will trip and open the contactor, cutting off power to the motor and preventing damage.
Stop Button: To stop the motor, a "stop" button is pressed. This action interrupts the electrical signal to the coil, de-energizing the magnetic field.
Opening of Main Contacts: When the coil is de-energized, the magnetic field collapses, and the movable iron core returns to its original position, opening the main contacts and cutting off the power supply to the motor, stopping its operation.
It's important to note that different motor starters may have additional features, such as thermal overload relays or electronic controls, to enhance safety and motor protection. The basic principle of using an electromagnetic contactor to control the motor's power supply remains consistent across various motor starter designs.
Magnetic Contactor: The heart of the magnetic motor starter is a component called the magnetic contactor. It consists of a coil and a set of contacts. The coil is an electromagnetic winding that, when energized, generates a magnetic field.
Start Button: To start the motor, a "start" button is pressed. This action sends an electrical signal to the coil of the magnetic contactor.
Magnetic Field Generation: When the coil receives the electrical signal, it becomes energized and creates a magnetic field around it.
Closing of Main Contacts: The magnetic field attracts a movable iron core within the contactor. This movement causes the main contacts (large electrical switches) to close, completing the circuit between the power source and the motor.
Power to Motor: With the main contacts closed, electrical power from the source flows through the contactor to the motor, causing it to start rotating.
Overload Protection: Additionally, motor starters often have overload protection built in. These devices monitor the current flowing through the motor. If the current exceeds a set limit, typically due to an overload or fault, the overload protection will trip and open the contactor, cutting off power to the motor and preventing damage.
Stop Button: To stop the motor, a "stop" button is pressed. This action interrupts the electrical signal to the coil, de-energizing the magnetic field.
Opening of Main Contacts: When the coil is de-energized, the magnetic field collapses, and the movable iron core returns to its original position, opening the main contacts and cutting off the power supply to the motor, stopping its operation.
It's important to note that different motor starters may have additional features, such as thermal overload relays or electronic controls, to enhance safety and motor protection. The basic principle of using an electromagnetic contactor to control the motor's power supply remains consistent across various motor starter designs.