HOW BIG IS TRANSFORMER FOR DEDICATED MOTOR START/RUN ?????

Transformer sizing for a dedicated motor start /run service. This video displays the various steps are required to be followed for calculation of transformer size, deployed for a dedicated motor service only.
Key words: Motor starting current, power factor, KVA, KW, KVAR, Transformer overload capability etc.

[@VARGHESEVS-e9k]

Thank you sir very useful informations

[@zyadalharbi180]

Thank you very much

[@kucingpowergile]

Good explanation..been searching sizing calculation for unit transformer of HV motor. The voltage drop I get was more than 20% if the transformer is sized at 1.2 times of motor rating..thanks a lot

[@amppowersystem6084]

1.5 times motor KVA should be adequate
Refer my video for more details

[@amppowersystem6084]

1.5 times is minimum Subject to low impedance . 2 to 2.5 times could be accepted if you go by standard transformer percentage impedance

[@kucingpowergile]

Thank you.. I find 2.5 times is adequate to rectify the starting voltage drop as simulated using ETAP.

[@BigAmp]

You are correct. I am an old timer and do not have ETAP but I use traditional manual spreadsheet calculations, aim for voltage at the motor not less than 80% and for DOL start transformer kVA size is about 2 - 2.5 times motor kW rating depending on actual motor locked rotor current and cable voltage drops (insignificant for MV motor but important for LV motor). The transformer acts like a poor mans reduced voltage starter.@@kucingpowergile

[@ajithjohnson5140]

very hard to understand

[@amppowersystem6084]

If you kindly let me know the exact point i may help you