Dol Starter: Buy Dol Motor Starter
DOL starter, also known as a direct-on-line starter, is a method of starting a 3-phase induction motor. In a DOL starter, a three-phase induction motor is connected directly across its 3-phase supply, and the DOL starter applies the full line voltage to the motor terminals. Direct-on-Line (DOL) Starter are highly reliable, time-tested, and suitable for wide range of agriculture and industrial applications.
The DOL starters are best for small motors that needs full power startup without speed control. The major benefits of this starter is that it is simple, easy to access and low cost solution for small motors. And DOL starter is a popular choice because of its simplicity and effectiveness for smaller, straightforward motor applications.
DOL Starter from our Leading Brand Siemens
A Siemens DOL starter is an electrical device that is made to effectively and safely start and stop electric motors. Offering a variety of motor starters that represent state-of-the-art technology and unparalleled performance, this company is a global leader in electrification, automation, and digitization. Siemens motor starters are the pinnacle of performance and cutting-edge technology. With the highest accuracy and efficiency, a Siemens motor starter guards against damage from overloads, short circuits, and other electrical issues while protecting the electric motor and electrical circuit.
Key Components of DOL Motor Starter
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Contactor: The contactor is an electromechanical switch that controls the power supply to the motor. It has a coil that, when energized, closes the main contacts and connects the motor to the power source.
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Overload Relay: The overload relay is a protective device that senses the current flowing through the motor. If the current exceeds a preset value, indicating an overload condition, the overload relay trips and opens the contactor, disconnecting the motor from the power supply. This protects the motor from damage due to overheating.
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Start/Stop Buttons: The DOL starter has separate start and stop buttons. Pressing the start button energizes the contactor coil, closing the main contacts and supplying power to the motor. The stop button de-energizes the contactor coil, opening the contacts and stopping the motor.
- Thermal Overload Protection: In addition to the overload relay, DOL starters often include thermal overload protection. This is achieved using thermal elements embedded in the motor windings. If the temperature of the windings exceeds a certain limit, the thermal elements trip and open the circuit, disconnecting the motor from the power supply.
How Does DOL Starter Works
- Full Voltage: When the starter is turned on, the motor gets full power right away, starting it immediately with maximum force.
- High Starting Current: This full power causes a high surge in current, usually 6–8 times the normal running current.
- Instant Speed: There’s no slow buildup of power, so the motor reaches full speed very quickly.
Frequently Asked Questions
Q1. What is a Direct On-Line (DOL) motor starter?
Ans. A DOL motor starter is a simple and widely used method for starting and stopping electric motors. It provides full voltage to the motor during the starting phase without any reduction in voltage or current.
Q2. How does a DOL motor starter work?
Ans. A DOL starter consists of a contactor, an overload relay, and start/stop buttons. When the motor is started, the contactor closes, connecting the motor directly to the power supply. The overload relay protects the motor against excessive current. The start button energizes the contactor, and the stop button de-energizes it.
Q3. What is the purpose of an overload relay in a DOL starter?
Ans. The overload relay in a DOL starter is a protective device that senses the current flowing through the motor. If the current exceeds a preset value, indicating an overload condition, the overload relay trips and opens the contactor, disconnecting the motor from the power supply. This protects the motor from overheating and damage.
