Question { 8099 }

why the frequency in india is 50 50HZ why we not select the
o ther frequncy range?

Answer

higher frequency give us higher output voltage ,india frequency selected 50hz if we select higher frequency then must be primemover speed more than 3000rpm . Above its speed only obtain by high temp.and pressure of steam.but indian metalorgy not take this temp.and pressure. if we given this then metal are melted.and also higher speed give higher centrifugal force on rotor .so causes india freq.50hz selected

Question { Vedanta, 12842 }

where do we connect tap of tap changer, to H.V. side or
L.V.side? and why?

Answer

always provide tap changer on hv side becouse
1.hv winding outside the lv winding easily we connect.
2.small current flow through it as compared to lv winding.
3.smoother control of the output voltage bcoz large turn ratio

Question { 7271 }

if one of the phase is failed to 3 phase IM. what will happen?

Answer

single phasing occur on motor so motor run 50%load for some time and draw more current causes more current overheating of motor and motor will burn after a certain time