Direct On Line (DOL) Starting

Question 1

Principle

Answer 1

DOL starting the motor is connected directly to the supply voltage allowing it to draw full line current and develop maximum starting torque

Question 2

Advantages

Answer 2

Simple and cost-effective.

Reliable with minimal components.

Provides high starting torque, ideal for small motors.

Question 3

Disadvantages

Answer 3

High inrush current (6-8 times the full-load current), which can cause voltage dips in the supply system.

Sudden torque can stress mechanical components and load systems.

Question 4

Applications

Answer 4

Used for motors with small ratings (typically below 10 kW) or where the power system can handle the inrush current without significant voltage drops.