DOL Starter basically comprises of only two buttons one of them is ‘green’ and the other is ‘red’.‘The green button is used for starting and the ‘Red’ button is used for stopping the motor. The Direct ON Line Starter actually consists of a contactor, an MCCB or circuit breaker, and an overload relay for protection whenever a fault condition occurs.
The above-mentioned two buttons ‘stop’ and ‘start’ or also called as ‘Red’ and ‘Green’ buttons are used to control the contacts.
For starting the motor, we press Green Button and the contact is closed, and therefore full line voltage start appearing across the motor. A contractor can either consist of 3 poles or 4-pole depending upon the design. In our case, the contactor used is of a 4-pole type.
There are three “Normally Open” contacts from where the motor is connected to the supply lines, and the fourth one contact is called as “hold on contact” which is an additional contact and this one energizes the contactor coil after the start or green button is released.
The additional coil gets de-energized if there is any fault occurs and then the starter disconnects the motor from the supply mains.
The DOL starter basically consists of two main protection parts
- Overcurrent Protection
- Overload Protection
Features
- Contact type: Magnetic contact
- Telemecanique DOL Motor starter
- Schneider electric
- Number of pole: 3pole
- Current Rating : 25A
- Switch type: Direct Online Starter
- Main voltage: 220v/240V AC
- Voltage rating: up to 500V AC