John from PA posted:How much else in the way of pertinent info may be in error?
By the way, in your calculation (see below) the "120" is line frequency so unless you have a 60 Hz source, the result of the calculation should be 8.33 RPM. But your motor speed of 995 agrees with a 6-pole motor on a 50 Hz supply.
Speed(RPM) = 120 f(Hz) / P(Poles)
So Fluctuation in speed will be 120*0.5/6=10 RPM
That mistake was due to some miss-understanding. There will be no other error in the provided information.
I think 120 is a constant in the formula (not Lf) whereas f(hz) is the line frequency. So to calculate the fluctuation of RPM, I used maximum fluctuation of frequency.