Recent content by Wedoca

Pete, if I understand this correctly.(S= R2/X)which defines the maximium torque and power of which happends when S = 1 when R2 match with X. I do not see that being consistant with the torque VS. Speed graph. because when S = 1 (RPM=0) thats when motor is energized and right before take off...

for "airgap torque is maximized when airgap power is maximized, which occurs when the component R2/s matches the source impedance X.... i.e s = R2/X" if that is the case, then if I take the first derivative of the P_gap with respective to S. I should recieve the same Resistance and Slip...

never mind again.....I got it ..... I just realized how much I have forgotten over the years ....maybe because I was probably never good at it the first place sorry for the confussion

correction to my question...... how do you derivate From equivalent circuit #2:I = V / sqrt(X^2 + R2^2/s^2)

never mind , I see it now

Tmech = Tag = Pag/wsyncTmech = (I^2*R2/s) / wsyncSubstitute our expression for I: Tmech = V^2 *R2 / [s*(X^2 + R2^2/s^2) *wsync] Tmech = V^2 *R2 / [(s*X^2 + R2^2/s) *wsync] Tmech = V^2 *R2/wsync *[(s*X^2 + R2^2/s)]^(-1) Substitude for I, what was the expression ??? I have difficulty...

to be more specific , comparing a S-cage motor to a slip ring motor....additional resistance are added to the rotor resistance to increase starting torque ( during take-off) of which will limit the inrush current.. but since Power is equal to torque * internal angular velocity W( when slip equal...

Pete, would you please show me the expressions of current , power , turque in terms of S ( in Zero to Breakdown Torque region ) since you first common , I have went back looking into couple books but yet , I am still having a hard to making connection between them Thanks

whats the Motor %ed number representing?

knowing Squirrel cage have high inrush current due to low rotor impedence and rotor impedence is equal to Xrotor + Rrotor and since X = jWL = j 2 pi f L Rotor impedence is at its max when f reachs the high point and vis versa, and as the (which above I can prove mathmatically) ""Rotor...

Thanks got it , it was IEC60034-6 Thanks again

guys , whats are some of typical motor cooling metheods ???

guys, .....question ...this might sound very elemetry but, I had to ask what determines the type of VFD set??(constant torque, constatnt speed, constant power) is it set by changing the drive parameter ??? or it is determine by the type of load or the motor??

great infor, Thanks guys

5 Hp, 480V, FLA: 8A, Lock Rotor Amp: 21A@460V and as far as the wire size : AWG 14