Motor Starter Coordination Type 1/2

A classification under IEC 60947-4-1 defining what damage is permitted in a motor starter combination (switch/fuse + contactor + thermal overload relay) after it has withstood a short circuit up to the specified fault current. Under coordination type 1, damage to the contactor and relay is permitted after the fault, as long as no danger to persons or the surroundings arises; repair or replacement of parts may be needed before the starter is returned to service. Under coordination type 2, no damage to the contactor or relay is permitted (slight contact welding that can be separated easily is allowed), and the starter must be ready for service again after the fault without parts replacement, other than replacing any blown fuses. Type 2 is typically required in critical processes where rapid restart after a fault is essential.