Recent content by Ryan P.E.

As zcore has said, not for a delta-wye transformer. The voltage across one phase of the high voltage side is 4600, and it is connected in delta already. The voltage across the corresponding low voltage winding is 460V, but 460V is the voltage from LN. The LL voltage would be 795V.

The 10:1 is supposed to be turns ratio, not the voltage ratio. With that being said, the LN voltage would 460V on the secondary or 795V LL, but I'm with you that this isn't a typical voltage for motor. If this were a question from school, I would've said 795V and put a note for the TA/teacher...

This all hinges on what 10:1 means. I am with the OP that it means turns ratio for a pair of windings on the same core, then calculate what the voltage would be depending on configuration, which would mean the LL voltage is 460*sqrt(3). But given NEMA typical voltage ratings and whats in the...

Are you talking about secondary impedance calculations like for distance relays like: Z2= Z1 * CTR/PTR? I never knew how this formula was derived, but I made sense looking at it like so: CTR=I1/I2 (primary divided by secondary) PTR=V1/V2 (primary divided by secondary) V1/I1 = Z1 (primary...

The basics of a VFD drive are: AC supply -> Rectifier Section to DC -> Inverter Section to PWM AC The voltage V=679V across the DC link is a DC voltage, not AC. If you imagine closing 2 transistors to complete a phase-to-phase circuit, the peak voltage phase-to-phase of the "PWM AC"...

See 1.1.2 and 1.1.6 from below http://www.propagation.gatech.edu/ECE3025/opencourse/THT/EmagNotes_Phasors.pdf Phasor's drop the "w" or frequency part, but you need to remember what it is in case you need to go back to a sinusoidal form which is the case here. 1) represent 359.3cos(wt) as a...