What component in a line starter is crucial for protecting the motor from overload conditions?

The thermal overload contacts are essential components in a line starter because they are specifically designed to protect electric motors from damage caused by overload conditions. When a motor experiences an overload, it draws more current than normal. The thermal overload contacts respond to the heat generated by this excessive current. As the temperature rises, these contacts open, disconnecting power to the motor and thereby preventing potential overheating, which can lead to burnout or other types of motor damage.

In contrast, interlock switches are primarily used to ensure that certain safety conditions are met before the motor can start. Capacitors are typically used in circuits to improve power factor or assist with starting various types of motors, but they do not offer protection against overloads. Relays can control the electrical supply to the motor but do not intrinsically monitor the motor's current or temperature like thermal overload contacts do. Thus, thermal overload contacts play a direct and vital role in safeguarding the motor's operation.