What is Motor Starter and Types of Motor Starters

What is a Motor Starter?

A motor starter is an electrical device that is used to start and stop a motor. The motor starter, like a relay, turns the power on and off, but unlike a relay, it also protects against low voltage and overcurrent.

 

The most important feature of a motor starter is to start an engine correctly, to correctly protect a motor from overheating, to drive in the opposite direction of a motor vehicle and low voltage and overcurrent protection for the motor.

 

A motor starter is made up of critical components that work together to manage and protect the motor.

 

Electrical Contactor: The purpose of an electrical contactor is to turn on and off the electricity supply to the motor by creating or breaking the touch terminals.

The purpose of the overload safety circuit is to protect the motor from harm caused by an overload condition. Large currents passing through the rotor have the potential to destroy the winding and other deliver-related equipment. It detects the current time and interrupts the electrical supply.

 

How a Motor Starter Works?

A starter is a control tool that is used to manually or automatically switch the motor on and off. It is used to control the secure ON/OFF of electrical vehicles by creating or breaking its connections.

 

The guide starter is used for smaller cars with a hand controlled lever that is manually turned on or off (flow the contacts position). The disadvantage of these types of starters is that they want to be replaced after the energy frailer has failed. They want guidance management for each (ON or OFF) operation, in other words. This technique can sometimes result in generating high currents within the motor winding, which might burn the motor. This is why it isn’t always recommended in most cases where alternative types of motor starters with safety features, such as electronic starters, are utilized.

 

Automated starters, which include electromechanical relays and contactors, are used to replace the ON/OFF action of motors. When the cutting-edge passes through the contactor coils, it energizes and forms the electromagnetic field, which draws or pushes the contacts to make the motor windings-to-power supply relationship.

 

Motors may be turned on and off using the begin and stop push buttons connected to the motor and starter. The contactor coils can be de-energized by pressing the prevent button, which causes the coil to be de-energized. As a result of the spring association, the contactor contacts return to their original position, resulting in motor transfer. In the event of a power loss or a guidance transfer-off operation, the motor will not start robotically until we manually start it by pressing the “begin push button.” The graphic below illustrates how a DOL motor starter functions in ON/OFF mode.

Type of Motor Starters:

We’ll go over the following types of cars and their starting methods, depending entirely on the benefits and drawbacks of the aforementioned motor starting methods.

Manual Starter

This type of starter is operated manually and no prior knowledge is required. A push-button is used to turn off and on the motor that is connected to it. The rear of the button has a mechanical transfer that stops or starts the motor by breaking or making the ne555n circuit.

 

They also provide overload prevention. However, such starters no longer include LVP (low voltage protection), which means they no longer break the circuit in the event of a power outage. Because the engine restarts while the energy is restored, it might be dangerous for some programs. As a result, they’re employed in a motor that uses very little electricity. The Direct On-Line (DOL) starter is a guide starter that protects against overload.

Magnetic Starter

Magnetic starters are the most common type of starter, and they’re typically utilized with high-voltage AC motors. These starters work in the same way as a relay does, using magnetism to break or form connections.

 

It has a lower and more secure starting voltage, as well as protection against low voltage and overcurrent. During a power outage, the magnetic starter breaks the circuit on a regular basis. Unlike guide starts, it operates automatically and from a distance, removing the operator from the equation.

 

Circuits are included in the magnetic starter.

 

The power circuit is responsible for supplying electricity to the motor. It has electric connections that, through an overload relay, turn on and off the power supplied from the deliver line to the motor.

The control circuit regulates the connections of the electrical circuit, allowing it to create or destroy power for the motor. To pull or push the electric contacts, the electromagnetic coil energizes or de-energizes. As a result, the magnetic starter may be controlled from a distance.

Direct Online (DOL) Starter

DOL aka Direct Online Starter is the only shape of motor starter that connects the motor without delay to the energy deliver. It includes a magnetic contactor that connects the motor with a deliver line & an overload relay for safety towards overcurrent. There isn’t anyt any voltage discount for secure beginning a motor. Therefore the motor used with such starters has under five hp rating. It has  easy push buttons that begin & prevent the motor.

 

Pressing the begin button energizes the coil that attracts the contactors collectively to shut the circuit. And urgent the prevent button de-energizes the contactor’s coil & pushes its contacts aside accordingly breaking the circuit. The transfer used for turning ON/OFF the energy deliver may be of any kind together with rotary, level, float, etc.

Stator Resistance starter

The RVS (reduced voltage starter) method is used to start a motor with a stator resistance starter. Every area of a three-section induction motor’s stator receives external resistance in collection. The resistor’s job is to lower the road voltage applied to the stator (by lowering the preliminary modern sooner or later).

 

Initially, the variable resistor is saved in the most resistance-inducing function. As a result of the voltage drop across the resistor, the voltage across the motor is kept to a minimum (safe level). The low stator voltage prevents the motor windings from being damaged by the first inrush current. As the motor’s speed increases, the resistance decreases, and the stator part is quickly connected to the power lines.

 

Rotor Resistance or Slip Ring Motor Starter

A whole voltage motor starting is used in this type of motor starter. Because it works well with a slip ring induction motor, it’s also known as a slip ring motor starter.

 

The slip ring connects external resistances to the rotor in supermegacelebrity aggregate. These resistors limit rotor current while increasing torque. As a result, the initial stator current is reduced. It also aids in the improvement of the electricity factor.

Autotransformer Starter

Such motor starters employ an autotransformer as a step-down transformer to reduce the voltage applied to the stator at some time during the first stage. It might be linked to each star’s and delta’s motors.

 

Every portion of the motor is connected to the secondary of the autotransformer. The autotransformer’s many tapings provide a fraction of the rated voltage. During starting, the relay is set to the begin role, which is the faucet factor that provides a reduced voltage for the startup. To increase the voltage with the rate of the motor, the relay changes among the faucet factors. Finally, it links it to the overall rated voltage.

 

It provides excessive voltage for a given starting current as compared to other voltage discount systems. It makes it possible to provide a higher starting torque.

 

Star Delta Starter

This is yet another common starting technique used in industries for large motors. To start the motor, the windings of a three-section induction motor are switched between large name and delta connections.

 

To begin, a triple pole double throw relay is used to connect the induction motor to the mains. The section voltage in a huge name connection is reduced by 1/three, and the starting modern-day as well as the beginning torque are reduced by 1/third of the normal rated amount.

 

When the motor accelerates, a timed relay changes the stator windings’ large name connection to the delta connection, allowing the total voltage to be maintained across all windings. The motor is set to its maximum speed.

Soft Starter

The voltage discount approach is also used by the gentle starter. It employs semiconductor switches such as TRIAC to control the voltage as well as the initial current supplied to the induction motor.

 

Variable voltage is provided using a phase-managed TRIAC. With the help of several TRIAC conduction perspectives or firing perspectives, the voltage may be varied. To reduce voltage, the conduction viewpoint is kept to a minimum. The voltage is increased on a regular basis by increasing the conduction viewpoint. From a conduction standpoint, the induction motor receives the entire line voltage and works at rated speed.

Variable Frequency Drive (VFD)

A Variable frequency drive (VFD), like a tender starter, may vary the voltage as well as the frequency of the imparting current. Because it is dependent on the deliver frequency, it is primarily utilized for managing the velocity of the induction motor.

 

With the help of rectifiers, the AC from the delivery line is converted to DC. Using a pulse width modulation technique and energy transistors like IGBTs, natural DC is converted into AC with adjustable frequency and voltage.

 

It provides you entire control over the motor’s speed, from zero to the rated speed. The variable voltage pace control option provides a stronger starting current and acceleration.

 

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