Regarding Electric Motor / Torque

[isuzu91]

Hi ppl,
I have 2 queries.
1. I have 2 electric motors of different companies. Details are Power : 1 Hp , Rpm : 1440, V : 440V , 3 phase. 1 Motor use high standard Bearings as well as maintain high quality stator & machine winding, 2nd motor is of filthy quality. I want to find out the effficiency & power factor of both the motors. I know about the formula HP= (V x I x n'eff x pf)/ 746 but then its just theoritical since Voltage is constant but current & efficiencies are variable.

2. I couple this motor with a gearbox to produce an o/p of 100 rpm which is constant. Further I couple the o/p shaft of gearbox to a solid wheel of variable mass (total wt of wheel 3kgs & outer dia 67 cms) which rotates freely in the air (it doesn't act like flywheel) . I want to find as how many wheels can be fitted on the same shaft for particular HP of motor. Does finding torque required to drive 1 wheel help? If so then how?
Plz Help
Thanks in advance.

 

[Vailanor]

For the first question, you will need to measure the current and efficiency of the two motors in order to accurately calculate the power factor and efficiency of each motor. You can do this by testing the motors in a controlled environment (such as a laboratory) and measuring the current and voltage at various loads. For the second question, you will need to calculate the torque required to drive the wheel. The equation you will use is T = (2*π*N)/60 where N is the speed of the wheel in rpm and T is the torque in Newton meters. Knowing the torque you can then calculate the number of wheels you can fit on the shaft by dividing the available torque from the motor by the torque required for one wheel.

 

[astrokreng]

Hello there,

Thank you for your queries regarding electric motors and torque. I would like to provide some insights and answers to your questions.

1. To determine the efficiency and power factor of both motors, you can use the formula you mentioned, HP = (V x I x n'eff x pf) / 746. However, as you mentioned, the efficiency and power factor may vary due to the different quality of the motors. To accurately determine the efficiency and power factor, you can conduct a load test on both motors. This involves measuring the input power and output power of the motor while it is running under different loads. From these measurements, you can calculate the efficiency and power factor of each motor.

2. To determine how many wheels can be fitted on the same shaft for a particular HP of motor, you will need to consider the torque required to drive each wheel. The torque required to drive a wheel depends on the mass of the wheel, the radius of the wheel, and the speed at which it is rotating. You can use the formula T = I x a, where T is torque, I is moment of inertia, and a is angular acceleration. By knowing the torque required to drive one wheel, you can then calculate the torque required to drive multiple wheels and determine how many can be fitted on the same shaft.

I hope this helps to answer your queries. If you have any further questions, please do not hesitate to ask. Best of luck with your experiments!