Single Phase Motors pptx

Single Phase Motors
•
Similar to a 3 phase
induction motor with
squirrel cage rotor
and main stator
windgs.
Main wndgs
Start wndgs
Laminated stator slots
Rotor
Wndgs
Centrifugal switch

Run (main) and Start (Aux) Windings
•
The stator has two sets of
windgs, Run (which is of
thicker size to reduce I²R
losses) and Start of thinner
size is placed 90˚ apart.
•
Run has relative Large
number of turns.
•
Aux has relative Small
number of turns.

Starting Torque in Single phase motor
•

To produce a starting torque a
rotating magnetic field must be
produced.
•
This is done by including the Aux
winding.
•
When an AC source is applied the
main windg produce a flux while
the Aux wndg produces a flux
Since the angles are out of phase a
resultant rotating field is created
•
A centrifugal switch disconnects the
Aux. wndg from the supply after it
has run up to 75% of full speed.
m
Φ
m
Φ
aΦ
Split Phase Principle