calculating inductance from the power factor of a 240vac motor

Thread Starter

denison

Joined Oct 13, 2018
91
What is the formula for the inductance if the power factor for a 240vac motor is known? I don't know if its even possible to do this. Does any body know?
 

Thread Starter

denison

Joined Oct 13, 2018
91
no load on the motor. I can get the power factor from a 'reduction revolution' power meter. So then is there a formula for the inductance of the motor? I can also measure the resistance with a multimeter and the current.
So then it must be possible to calculate the inductance from a formula.
There are inductance meters but they are quite expensive.
 

crutschow

Joined Mar 14, 2008
24,997
You'd have to know the motor current and voltage when the PF was measured.
From that you can calculate the inductance as if it were a series RL circuit.
 

Thread Starter

denison

Joined Oct 13, 2018
91
do you have the equation for that Mr Crutschow? Other people on this forum are asking why I need the inductance. It is because I want to model a 240vac motor on Ltspice to try to solve spike problems I am having at switching the motor.
 

Thread Starter

denison

Joined Oct 13, 2018
91
I have done phasor calculations in the past but now forget much of it. I have been looking for an online calculator to do the calculations for me. Putting in voltage, current and power factor.
Unfortunately I cannot find one. There are some great maths and electronic calculators now in the cloud which saves pages of hand calculations.
Can one of you guys point to an online inductance calculator using V,I and PF?
 
Top