Short circuit protection of motor starters-IEC Type 2 coordination

The International Electrotechnical Commission (IEC) 947-4-1 standard requirements for claiming compliance with Type 2 coordination are explained. The history of Type 2 coordination and its benefits are discussed. Various methods of achieving Type 2 coordination and an extensive test program for both NEMA and IEC motor starters are discussed. For simplicity, the focus is on Type 2 coordination as it relates to fuses and magnetic starters installed in any typical industrial control panel, which may include a fusible disconnect switch, motor starters, control relays, push buttons, etc.<>