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Dec 19, 2023 · As a common technique for starting induction motors, the “Across the Line” method is one of the most popular methods for starting motors. The windings of the motor are directly connected to the power supply at full voltage during the starting phase of the motor.
Across the line start circuitry is by far the most common starting circuit encountered. It is also the circuity that experience the highest current during motor starting. Across the Line Starting Circuit. When the contactor coil is energized, the L1-3 contacts close and line voltage and starting current is connected directly to the stator windings.
- What Is Dol Starter?
- Dol Starter Wiring Diagram
- 3 Phase Motor Starter with Overload Protection
- Dol Starter Working Principle
- Advantages of Dol Starter
- Disadvantages of Dol Starter
- Dol Starter Applications
A DOL starter (also known as a direct on line starter or across the line starter) is a method of starting a 3 phase induction motor. In a DOL Starter, an induction motoris connected directly across its 3-phase supply, and the DOL starter applies the full line voltage to the motor terminals. Despite this direct connection, no harm is done to the mot...
The wiring diagram for a DOL stater is shown below. A direct online starter consists of two buttons, a GREEN button for starting and a RED for stopping purpose of the motor. The DOL starter comprises an MCCB or circuit breaker, contactor and an overload relay for protection. These two buttons, i.e. Green and Red or start and stop buttons control th...
When a motor draws excessive current to meet the load requirements such that this load requirement goes beyond the rated limit, this is known as overload. Thermal overload protectionis a type of security when the motor draws over current or excessive current and causes overheating of the equipment. Overload is also the type of over current. So over...
The working principle of a DOL starterbegins with the connection to the 3-phase main with the motor. The control circuit is connected to any two phases and energized from them only. When we press the start button, the current flows through the contactor coil (magnetizing coil) and control circuit also. The current energises the contactor coil and l...
The advantages of a DOL starter include: 1. Simple and most economical starter. 2. More comfortable to design, operate and control. 3. Provides nearly full starting torque at starting. 4. Easy to understand and troubleshoot. 5. DOL starter connects the supply to the delta winding of the motor.
The disadvantages of a DOL starter include: 1. High starting current (5-8 times of full load current). 2. DOL Starter causes a significant dip in voltage, hence suitable only for small motors. 3. DOL Starterreduces the lifespan of the machine. 4. Mechanically tough. 5. Unnecessary high starting torque
The applications of DOL starters are primarily motors where a high inrush current does not cause excessive voltage drop in the supply circuit (or where this high voltage drop is acceptable). Direct on line starters are commonly used to start small water pumps, conveyor belts, fans, and compressors. In the case of an asynchronous motor (such as the ...
Dec 12, 2023 · Choosing the right starting method minimizes stress on the motor and ensure a reliable and efficient start-up. This article will cover the following motor starting methods and their strengths and weaknesses: Across the Line; Reduced Voltage; Multispeed; Across the Line Method
Sep 27, 2016 · The simplest method is by closing a contactor and allowing the motor to start at full voltage, or known as Across The Line (ATL). Today’s motor control applications, such as ATL starters are...
DOL Starter (Direct Online Starter) is also knows as “across the line starter”. DOL starter is a device consist of main contactor, protective devices and overload relay which is used for motor starting operations. It is used for low rating usually below 5HP motors.
Feb 1, 2024 · One of the most basic motor starting methods is an across-the-line motor starter, which is also known as full-voltage or direct-online. An across-the-line motor starter typically includes three components: the contactor, the motor circuit protector and the overload relay.
