GB/T 21972.3-2013

This standard specifies the technical requirements, test methods, and inspection rules for YZP series variable-frequency three-phase induction motors with centrifugal fan cooling, specifically designed for crane and metallurgical applications. It is applied in heavy industrial environments such as steel mills, foundries, and port facilities where motors must withstand high temperatures, dust, and mechanical shock while providing precise speed control for hoisting, traveling, and tilting operations. The standard ensures reliable performance under variable-frequency drive conditions, including constant torque and constant power operation, for equipment like overhead cranes, ladle turrets, and rolling mill auxiliaries.