Question { Siemens, 9854 }

what is difference between short ckt and overload?

Answer

in short ckt the potential difference b/w phases or b/w
phase & ground becomes zero &very high current flows
bt in over load condition only current greater than rated
value flows..

Question { 9105 }

in ceiling fan and table fan what is the rotating part and
what is the stationary part?

Answer

in ceiling fan field winding is rotating part...in table fan
rotor is rotating part.so their direction of rotation is
opposit to each other.

Question { 8210 }

why single induction motor is not self starter?

Answer

in single phase induction motor stator has single phase
winding,when we give single phase supply, it creats a
pulsating magnetic flux in the air gap but for rotor
rotation there should be a rotating flux.so it is not self
starting.
for starting either auxiliary winding or any means which
splits the single phase flux in at least 2 phase flux can be
used