Why different values of B’s (magnetic flux density) are
chosen for DC machines and Induction Motors?

Answer Posted / iamdon

Induction Motors are designed for COMPARATIVELY LOW VALUE
OF B.Because if we select higher value of B,the magnetizing
current requirement for establishing the working flux in
the air gap will became high.This reduces the power factor.
This condition is undesirable hence must be avoided.

DC machines are designed for COMPARATIVELY HIGH VALUE OF B.
Because if we select lower value of B,the amount of force
developed will became small.Since there are large spaces
available on poles,so we have no difficulty in putting
extra number of turns on it for getting higher value of B.

Author:arbelectbit@yahoo.com

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