Originally Posted by eJets
your bench testing must not necessarily generate better results than the munufacturer data as the manufacturing process it self leads to a statistical spread - to take this spread into account and smoothen the manufacturing spread you should have tested at least 5 to 10 motors of the same type - did you?
the mean figuers of the manufacturer resulting from tests over more than one motor of the same type - this is how the quality testing of the mufacturing process is done....
The Iron Loss is only indirect related to the RPM - It is related to the magnetic Cycles and these depends not only on the RPM but also on the numer of magnetic pols.
Further more the CC eCalc
does extrapolate the Iron Loss (Io) from the mesured mag. cycles (@ Io Voltage) to the effectiv mag. Cycles (at operational Voltage) by using an adequat mathematic model.
nevertheless your Calc is also well done.....
Question 1: Yes, I have tested only one sample
Anyway some data from some
manufacturers are not accurate
Question 2: For a given motor, the number of magnetic poles is fixed