What is the requirement of motor starter?

Motor starters consist of two devices—a contactor that completes the circuit to the motor and an overload relay that monitors the current the motor is drawing. This overload protection device is set to a pre-determined maximum load that the motor can safely handle.

What are the different types of motor starter used in induction motor?

Types of Magnetic Motor Starters

• Direct-On-Line Starter. The direct-on-line starter is the simplest form of motor starter, other than a manual starter.
• Rotor Resistance Starter.
• Stator Resistance Starter.
• Auto Transformer Starter.
• Star Delta Starter.

Why the starting current of an induction motor is very high?

At start, the reactance of the rotor is high because the slip of the motor is equal to unity. The value of Rr/s increase as the slip gets decrease. When the induction motor is started the rotor reactance is more than the rotor resistance and because of the large Xr/Rr ratio the motor takes large inductive current.

Can a single-phase motor run without a capacitor?

A single phase capacitor run motor will not be able to start without capacitor, since torque is missing. Motor is not designed to give full torque without capacitor. So even if it were to mechanically start with a force, it doesn’t achieve full speed, and will not be able to take load.

Why a single-phase induction motor requires a means of starting?

The Single Phase Motor is not self-starting and hence needs an auxiliary means or equipment to start the single-phase induction motor. Mechanical methods are impractical and, therefore the motor is started temporarily converting into a two-phase motor.

Why single phase motors are not self starting?

Single phase induction motor has distributed stator winding and a squirrel-cage rotor. When fed from a single-phase supply, its stator winding produces a flux ( or field ) which is only alternating i.e. one which alternates along one space axis only. That is why a single phase motor is not self-starting.