IEC Type 2 coordination for short circuit protection of motor starters

Users of electromechanical motor starters have come to recognize that simply utilizing starters that meet UL requirements and installing those starters in accordance with the National Electrical Code does not eliminate the possibility of severe damage to the starter and other control panel equipment in the event of a short circuit fault. This paper explains what Type 2 Coordination is, its history, and the IEC 947-4-1 test requirements and pass/fail criteria to claim compliance with Type 2 Coordination requirements. Various methods of achieving Type 2 Coordination, and an extensive test program of both NEMA and IEC motor starters is addressed