What is the current of a 55kw, grade 8 motor?
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What is the current of a 55kw, grade 8 motor? How to calculate
This post was last edited by chb1534 on 2016-1-6 at 15:07. Theoretically, P=1.732UI*0.85 (power factor); in practice, the motor efficiency also needs to be taken into account. For a 55KW motor, the efficiency is generally around 0.90-0.95, so 0.9 will be used for calculation purposes here. P=1.732UI*0.85*0.9; therefore, for a 55KW motor, the current I=55000/1.732*0.85*0.9*380=109.2A. The efficiency and power factor can be set at lower values here; if the motor is of better quality, the current will be less than 109A, but generally it will not be less than 100A. Additionally, level 8 is only related to speed and has nothing to do with current.
Reference can be made to Chapter 9 of the \"Manual for Industrial and Civil Power Distribution Design (3rd Edition)\"
Estimate for a 3-phase asynchronous motor at 380V, using 2A per kilowatt
The current is 105A, with a fluctuation of 2A up or down.