Induction Motor Default starting PF and LRA

Q: Where does the induction motor default values for starting PF of 0.2 and inrush current (LRA/FLA) of 6.5 based from?

A: The default starting power factor of 0.2 is based on the suggestion from the Brown book IEEE 399-1997, section 9.5.2:





The inrush current or locked rotor current (LRA/FLA) is typically 6 x FLA (Code Letter G) per the Brown book in the same section above. However, we used the NEMA standard typical values from table 11 (Typical Chracteristics and Applications of Fixed Frequency Small and Medium AC Squirrel-Cage Induction Motors) based on the Design type of the motor (instead of the Code letter). In this table, the typical inrush is about 6-7 x FLA. The default is using the median value of 6.5.


Creation date: 12/27/2016 3:14 PM     Updated: 3/13/2017 11:18 AM