Page 306 - Electronic Mechanic - TP - Volume - 2

ELECTRONICS MECHANIC - CITS

EXERCISE 207: Familiarize with different types of AC motor

and demonstrate the different parts

Objectives

At the end of this exercise you shall be able to:
• to demonstrate all parts of the AC motor.

Requirements

Tools/ Equipments/ Instruments Materials/ Components
• Combination Plier 250mm - 1 No. • Induction Motor - 1 No.
• Screwdriver Set 150mm - 1 No. • Circuit Barker - 1 No.
• Wire Stripper - 1 No. • Push Button NO/NC - 1 No.
• Overload Relay - 1 No.
• Contactor - 1 No.

Procedure

AC Motor: - An AC motor is an electric motor driven by an alternating current. The AC motor commonly consists of
two basic parts an outside stator having coils supplied with alternating current to produce a rotating magnetic field
and an inside rotor attached to the output shaft producing a second rotating magnetic field. The rotor magnetic
field may be produced by permanent magnets, reluctance saliency, or DC or AC electrical windings.

Less common, AC linear motors operate on similar principles as rotating motors but have their stationary and
moving parts arranged in a straight-line configuration, producing linear motion instead of rotation.
Operating principles :- The two main types of AC motors are induction motors and synchronous motors. The
induction motor always relies on a small difference in speed between the stator rotating magnetic field and the
rotor shaft speed called slip to induce rotor current in the rotor AC winding. As a result, the induction motor
cannot produce torque near synchronous speed where induction is irrelevant or ceases to exist. In contrast, the
synchronous motor does not rely on slip induction for operation and uses either permanent magnets, salient
poles or an independently excited rotor winding. The synchronous motor produces its rated torque at exactly
synchronous winding that does not rely on the principles of slip induction of current. The supply frequency of sub
to super multiple of the supply frequency.
Other types of motors include eddy current motors and AC and DC mechanically commutated machines in which
speed is dependent of voltage and winding connection.
Types of AC motor : -
AC motor

Single Phase motor Three Phase motor

Split phase induction motor Squirrel cage induction motor
Capacitor start inductor motor Double squirrel cage motor
Capacitor starts capacitor runs induction motor Slip ring or wound rotor induction motor
Permanent split capacitor motor
Shaded pole induction motor

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