What is the function of blowout coils in medium-voltage motor starters?

The primary function of blowout coils in medium-voltage motor starters is to create a magnetic field that helps draw the arc into the arc chute during the interruption of current. When the circuit opens to stop the motor, an electrical arc can form as the contacts separate. The blowout coils generate a magnetic field around the contacts that assists in elongating and directing the arc into an area where it can be safely extinguished, typically referred to as the arc chute. This process is crucial for the effective and safe operation of medium-voltage starters, as it minimizes the risk of damage to the equipment and contributes to the overall reliability of the starter.

The effectiveness of blowout coils in extinguishing arcs is essential in preventing electrical hazards and ensuring that the motor can be restarted safely after a fault condition.