This standard specifies the basic requirements for electromagnetic starters for industrial machinery. It includes the characteristics of the starter, the relevant conditions that the starter should follow, the structure and insulation performance, and the test methods of difficult starters, and stipulates the main technical parameter secret data provided by the manufacturer to the user. The starter is mainly used to control the direct starting, stopping and forward and reverse rotation of the three-phase squirrel cage induction motor, and can protect the motor from overload and phase failure.