determining values for starter capacitors 1

[pcb22000]

how do i determine the value of a starter capacitor for an electric motor? is there a standard procedure/formula? if so, what is it? thanks!

 

[wired1]

There may be standard designs that all the motor mfrs use but I'm not sure. The best way is to contact the mfr. I can tell you that value of the capacitance will affect the torque of your motor. Also, another rule says to use a voltage of 1.5 x the highest the voltage the motor sees. The motor mfr may not tell you this.

 

[SteveKW]

Do a search on this site for more information.

If you have the motor and do not know the size of cap ... post the motor info and I may recognize it!

 

[js9308]

I somewhere read many years ego that a rule of thumb is a 1 KVAR of capacitor for each HP of motor power

 

[wired1]

pcb22000:
My statement about the torque of the motor actually refers to a "capacitor run" motor. Please pardon my error on that point.

 

[jbartos]

Suggestion: It is better to contact the motor manufacturer for a designed or suggested capacitor value since the exact calculation would need motor parameters and curves.
Visit

http://www.iprocessmart.com/techsmart/basictraining.pdf

for motor basics

 

[pcb22000]

just wanted to say thanks to all you folks for responding to my question. best regards to all of you!