Starting Power Factor
Starting Power Factor
(OP)
Dear everybody,
Do you know about Starting Power Factor?
How to know it?
What is the formula?
Thank you for your attention.
Regards
Do you know about Starting Power Factor?
How to know it?
What is the formula?
Thank you for your attention.
Regards





RE: Starting Power Factor
RE: Starting Power Factor
The power factor at start is initially between 0.1 and 0.2 and increases as the rotor speeds up reaching a maximum whinch is motor design dependant just before full load speed. The power factor of an unloaded motor then drops down again between the speed of maximum torque and synchronous speed.
Best regards
Mark Empson
http://www.lmphotonics.com
RE: Starting Power Factor
http://www.tornatech.com/contenu/ulfm_wye_delta_open_transition_ang.cfm
where the starting power factor = 0.4
http://www.nts.no/norsok/e/E00104.pdf
where the typical starting power factor = 0.2
and
IEEE Std 141-1993 Red Book "IEEE Recommended Practice for Electric Power Distribution for Industrial Plants,"
Figure 8-11 Motor Characteristics for Typical Medium-Sized and Medium-Speed Induction Motor
where the starting power factor = 0.2
RE: Starting Power Factor
by the way, how to calculate the starting power factor..?
RE: Starting Power Factor
For some applications it is sufficient to assume a value such as 0.2, or sometimes use arithmetic vs vector calcs. It will depend on your specific application and what you are trying to accomplish and how accurate you need to be.
RE: Starting Power Factor
PF=Rr'/[(Rr')**2 + (ws x Llr')**2]**0.5, in per unit