Characteristic and use:
YZR. YZ. Series motors for crane and metallurgical uses, featured with large overload capacity and adequate mechanical strength, are specially suitable for driving various types of crane and metallurgical machineries or other similar equipment.

YZR series motors are of wound rotors type, while YZ series motors are of squirrel cage type.

Electrical machinery performance:
There are eight types of duty type for these series motors, S2, S3, S4, S5, S6, S7, S8 and S9. The basic duty type is S3-40% (duty type is S3, cyclic duration factor is 40%, each cyclic is 10min). The following duty type are most useful to these series motors.
1. Short-time duty type (S2)
Operation of constant load during a given time, less than that required to reach thermal equilibrium, followed by a rest and de-energized period of sufficient duration to re-establish machine temperature within 2 deg K of the coolant.
2. Intermittent periodic duty type (S3)
A sequence of identical duty cycles, each including a period of operation at constant load and a rest and de-energized period but the operation period are so short that it is not sufficient for the machine to reach thermal equilibrium In this duty type, the cycle is such that the starting current does not significantly affect the temperature rise.
3. Intermittent periodic duty type with starting (S4)
A sequence of identical duty cycles, each including a significant period of starting, a period of operation of constant load and a rest and de-energized period, but the operation period are so short that it is not sufficient for the machine to reach thermal equilibrium.
4. Intermittent periodic duty type with electric braking (S5)
A sequence of identical duty cycles, each consisting of a period of starting, a period of operation at constant load and a rest and de-energized period, but the operation period are so short that it is not sufficient for the machine to reach thermal equilibrium.