Tom Jenkins
Lifetime Supporting Member
I am interested in measuring actual motor power. I think that motor slip is directly proportional to torque, and given torque and rpm hp is readily determined.
The fundamental equation,as I understand it, is simple: actual T = actual rpm/nominal rpm x nominal T
Measuring rpm is simple. Full load rpm and hp (hence torque) is on the motor nameplate. I have some questions about implementation:
1) how accurate is the nameplate rpm?
2) is the full load rpm going to vary across individual motors of the same manufacture, model, and hp or is it pretty consistent?
3) what is the probable accuracy of this technique, assuming my rpm measurement is accurate?
The fundamental equation,as I understand it, is simple: actual T = actual rpm/nominal rpm x nominal T
Measuring rpm is simple. Full load rpm and hp (hence torque) is on the motor nameplate. I have some questions about implementation:
1) how accurate is the nameplate rpm?
2) is the full load rpm going to vary across individual motors of the same manufacture, model, and hp or is it pretty consistent?
3) what is the probable accuracy of this technique, assuming my rpm measurement is accurate?