crane electric motorused for port construction of ZPMC, paper-making mill crane high efficient, overload dc motor controller Requirments for use of crane electric motor 1. The allowable ambient temperature for the operation of the motor is below 30 certigrade to above 40 centigrade, and the allowable see level is not higher than 1000m. 2. The supplying electric source of the motors adopts recitified electric source or DC generator electric source. When adopting 3 phase, fully controllable bridge rectified electric source, the motors can work for a long period without outer smoothing reactor. Products Specification on crane electric motor 1. There are 2 kinds of rated voltage of the crane electric motors: 220V, 440V. As required, the motor with other voltage level can be produced. 2. The mode of excitation of motors is separate excitation. The voltage of excitation is 180V or 310V. As required, the motors with other voltage level can be produced. 3. The motors running at basic speed can reach max. rotating moment regulated in the technical date, it will last 60s. 4. For the motors of rated voltage 220V, the rotating speed can reach as 2 times as the rated rotating speed through increasing the applied voltage. At this time, the allowable max.rotating moment, it will last 15s. 5. For the motors of rated voltage 220V, the max. rotating moment is as 0.6 times as the rated rotating moment when the motors are running with low intensity magnetic rotation regulated in the technical date table. it will last 15s. 6. The standard position of wire outlet box of the motors is no the right of the machine base plate seen from the drive end. If required, it can be mounted on the left of the machine base plate. If so, this requirement should be stated in the order.