Why neutral not necessary for 3 phase induction motor?

Question

Why neutral not necessary for 3 phase induction motor?

Answer 1

Because the windings are connected from phase to phase, there is no need for neutral.

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Answer 2

Neutral conductor in 3-phase systems normally carries no current and therefore is unnecessary. It is cheaper to install a smaller grounding wire to the motor housing and the common factory grounding rod.

Answer 3

The three phase induction motor has 2 parts

1-star winded stator

2-squirrel cage rotor

to make the rotor rotate the emf has to be created

here we have 3 phases in 3 different time difference 120 degrees

[if you keep 3 LED's in a circular manner and light them up in three different time gaps u feel like they are rotating]

the same way the emf rotates the squirrel cage rotor to rotate

there's no need for neutral as the phase difference is created by RYB itself.In some cases you can see the neutral is connected to a three phase motor but actually they are grounded inside.

Faraday's law the induced emf's frequency is directly propotional to the supply frequency so speed control can be acheived by changing supply frequency.

Answer 4

The long answer can be found at wiki.

Answer 5

Because 3-phase induction motors are designed to present a balanced load to the 3-phase supply. When the load is balanced, even if it is wye (star) connected and a neutral connection is provided, no current flows in the neutral conductor.