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They are a really heavy duty switch and are used because they can handle high current(amps) caused especially while the motor gets up to full speed, and can handle repeated starting and stopping of the motor several times an hour if needed without wearing out, overheating or causing overload problems. Also called a contactor, it uses an electromagnetic coil that works on a lower voltage, usually whatever the control panel voltage is (24vac is most common in USA, when you push the start button it energizes the coil that slams a set of three contacts(six all together for three phase)together very tightly to complete the power circuit to the motor. The contacts inside the contactor used to be pure silver, now they are mostly copper with a thick pure silver coating on the contact surfaces.

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Q: Why magnetic starter switch is used for 3 phase delta motor?
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What will happen if induction motor is in star-star connected?

If a motor is connected in a star configuration it will operate at a slower speed. This is the working process that a star delta starter operates on. At first through the starter the motor starts in the star connection. When the motor gets up to its highest speed in that connection it times a timer out , the star starter drops out and the delta starter pulls in and then connects the motor in the delta connection. This allows more voltage to be applied to the motor and it then speeds up to its nameplate rated RPM.


What device may be wired into the starting circuit of a motor to improve the starting torque?

I assume a 3 phase, AC induction motor. A star delta starter or a soft starter can be used. A soft starter is better compared to a star delta starter, but it is more expensive.


How much KW range can be use star-delta starter?

The use of a star delta starter is for motor control only and not resistive heating loads. This type of starter is used to dampen the inrush current by using a lower voltage to start the motor.


What are magnetic shading coils and what do they do in a magnetic motor Starter?

Shading coils provide a phase shift between the magnetic field of the rotor and stator, which is necessary to get the motor spinning.


What is a forward-reverse star delta?

A forward reverse star delta is a two in one motor starter where a motor first runs on star connection and then changed to delta connection after a time which has been set. The motor direction can be changed, whether forward or reverse

Related questions

Why is the automatic star to delta starter tripping?

The only thing that will trip the starter, is the load of the motor. Check the motor leads to make sure you have not crossed them over coming from the motor junction box. If the motor current is normal nameplate full load amps when run across the line then reduce the timing of the timer on the switch over from star to delta.


The function of the solenid switch on the starter motor?

solenid switch engages and disengages the bendix on the starter


When is starter motor relay for 1991 Nissan terrano?

You can find the 1991 Nissan starter motor relay switch in the fuse box. The starter motor relay switch will be in the third column, second from the bottom.


What does a car starter motor solenoid do?

When opened by the starter switch, it sends electricity from the battery to the starter motor to start the car.


What will happen if induction motor is in star-star connected?

If a motor is connected in a star configuration it will operate at a slower speed. This is the working process that a star delta starter operates on. At first through the starter the motor starts in the star connection. When the motor gets up to its highest speed in that connection it times a timer out , the star starter drops out and the delta starter pulls in and then connects the motor in the delta connection. This allows more voltage to be applied to the motor and it then speeds up to its nameplate rated RPM.


What device may be wired into the starting circuit of a motor to improve the starting torque?

I assume a 3 phase, AC induction motor. A star delta starter or a soft starter can be used. A soft starter is better compared to a star delta starter, but it is more expensive.


How can you include phase failure relay in your star delta motor starter circuit?

The star delta motor starter circuit has to have a control voltage to energize the motor magnetic contractors. A phase failure relay monitors all three phases of the incoming supply lines. The phase failure relay also has auxiliary contacts on it. There are usually two sets of "C" form contacts. The control voltage for the starter circuit must be connected across the normally open (N.O.) contacts of one of these two sets. When the phase monitor is energized these N.O. contacts close supplying the control voltage to the circuitry of the star delta starters. If there is a phase interruption, phase reversal or phase loss, the phase failure relay will de-energize and the N.O. contacts will go back to their de-energized state. If the star delta motor starter is in use at the time, its control circuitry voltage will be lost and the delta motor magnetic contactor will open. The opening of this contactor will disconnect the motor from the failed three phase supply.


How much KW range can be use star-delta starter?

The use of a star delta starter is for motor control only and not resistive heating loads. This type of starter is used to dampen the inrush current by using a lower voltage to start the motor.


When star-delta starter timer will disconnnect?

its is very simple whem motor shifted on delta then timer will disconnect


What are magnetic shading coils and what do they do in a magnetic motor Starter?

Shading coils provide a phase shift between the magnetic field of the rotor and stator, which is necessary to get the motor spinning.


Why using on motor star delta starter?

because at the starting the induction motor drawn a heavy current thats why we use starter to increase the starting resistance of the induction motor!


What component used to start a modern induction motor?

Star delta starter