DOL STARTER (DIRECT ON LINE STARTER)
Three phase induction motor draws a very high starting current. This starting current know as the Inrush current,(Inrush current is 4-6 times of rating current or full load current ) which can damage the motor winding. To avoid any type of damage in motor winding. There are use different types of methods to start an induction motor. These methods depend on the load connected to the motor and it's rating.
What is DOL starter?
Direct on line starter is also called DOL STATER.
DOL stater is a motor starting method which is commly use to start 3 phase small induction motor rating up to 10 HP or 7.50 KW. In this method the motor is directly connected to the three phase power supply. This is a simplest type of motor starter. we are easily operate a three phase induction motor with the help of DOL starter.
Why use DOL starter ?
DOL stater protect the motor from high starting current and also provide the protection during operation. DOL starter are used to start and stop a three phase induction motor with safely and easily.
* Power diagram of DOL starter.
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| Power diagram of DOL starter |
*Control diagram of DOL starter.
Control diagram of DOL starter
Advantages of DOL starter :-
1. DOL stater provides a high starting torque at starting.
2. It's most economical and simplest starter.
3. DOL starter is very easy to understanding and maintain.
4. It's very cheapest.
5. It's more comfortable for operating, controlling and design.
Disadvantages of DOL starter :-
1. It's reduces the lifespan of the motor.
2. It have unnecessary high starting torque.
3. DOL starter have high starting current (4-8 times of full load current)
4. It is mechanically hard.
5. DOL starter only suitable for small induction motor rating up 10 HP or 7.50 KW.