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Is 4 point starter used to start and control the speed of dc shunt motor with armature resistance control?
Wiki User
∙ 11y ago
yes
Wiki User
∙ 11y ago
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In what two ways can the speed of a dc motor be varied?
speed of a dc motor can be varied by mainly two methods:- 1)field control method 2)armature control method further , field control method can be divided in 3 parts:- 1)field rhestat control method---speed variation is acomplished by means of a variable resistance inserted in series with shunt field 2)reluctance control method---by changing the reluctance of magnetic circuit by choosing right material.. 3) field voltage control method-requires variable field voltage supply. and armature control method can be divided in 3 parts :- 1)armature resistance control---variable resisitance connected in series with armature 2)shunted armature control. 3)armature voltage control. ------------mrityunjay pandey (kiit university ,btech 2nd year)
Why a DC motor starter is called 3 point starter?
Because it has three terminals L , F and A L - Line (connected to Supply) F - Field (connected to field of dc motor) A - Armature (connected to armature of DC motor) that's y it is called 3 point starter :)
Why the armature current of a shunt motor decreases as the motor accelerates?
Without a mechanical load the motor accelerates until the back-emf generated by the armature nearly equals the supply voltage. On load, the speed drops and the current rises until the power taken from the supply balances the mechanical power supplied to the load. If the armature has low resistance, the speed drop under load is not very much, so speed regulation is better if the armature resistance is lower.
How do you measure the resistance of a motor?
we can measure the resistance of the motor by using voltmeter ammeter method of by directly using a multimeter across the armature terminals of the motor in voltmeter ammeter method we should use a less value of dc voltage to find the resistance
Why the armature rheostat of dc is motor kept at maximum resistance position?
It isn't. It is only kept at maximum resistance when the motor is not running. That is done to limit the starting current.
Explain the necessity for the use of a starter with a dc motor?
In its simplest form, the starter of a dc motor is a variable resistance in series with the armature circuit of dc motor to reduce the high starting current so that the armature winding does not get overheated and burnt while the motor isgetting started. As the rotating armature of dc motor picks up speed, the starter resistance is gradually reduced so that the motor is able to attain its full speed when the starter is not expected to offer any additional resistance in series with the armature winding of the dc motor. At full speed the motor starts running normally, of course, without the help of starter. In other words, the starter offers resistance to armature current during starting of dc motor only. Under normal working condition of dc motor , the starter is electrically out of armature circuit of the motor. The starter protects the armature of dc motor from getting damaged. The electromotive force (emf) induced in the armature winding during starting builds up from zero value to max value to restrict the armature current within the permissible value at full speed. As the speed of armature/motor build up, armature induced emf also starts building thus reducing the role resistance offered by the starter, hence requiring it to gradually reduce as the motor picks up full speed.
Why armature resistance is less than 1 Ohm?
why armature resistance is very low as compare to field resistance in dc motor
What device has a coil armature and heaters?
A motor starter.
When operated the starter motor solenoid moves the plunger to engage the?
armature
In what two ways can the speed of a dc motor be varied?
speed of a dc motor can be varied by mainly two methods:- 1)field control method 2)armature control method further , field control method can be divided in 3 parts:- 1)field rhestat control method---speed variation is acomplished by means of a variable resistance inserted in series with shunt field 2)reluctance control method---by changing the reluctance of magnetic circuit by choosing right material.. 3) field voltage control method-requires variable field voltage supply. and armature control method can be divided in 3 parts :- 1)armature resistance control---variable resisitance connected in series with armature 2)shunted armature control. 3)armature voltage control. ------------mrityunjay pandey (kiit university ,btech 2nd year)
In DC motor is the armature plus brushes resistance substantially the same for every rotational position of the armature?
yes
why starter motor armature over heat?
Usually caused by worn bearings.
Why motor has large winding in shunt resistance than armature resistance?
A motor with large windings will have greater shunt resistance than armature resistance due to the sheer amount of copper wire it must travel through. The gauge of the wire also plays a part in this process.
What are components of a DC motor starter that can be affected by a high starting current if it is not limited?
armature
Why 3 point starter is called 3 point starter?
Because it has three terminals L , F and A L - Line (connected to Supply) F - Field (connected to field of dc motor) A - Armature (connected to armature of DC motor) that's y it is called 3 point starter :)
Want to know about two point starter?
In DC series motor, field and armature are in series. so we use only two points. They are line and armature. therefore we use two point starter.
Why a DC motor starter is called 3 point starter?
Because it has three terminals L , F and A L - Line (connected to Supply) F - Field (connected to field of dc motor) A - Armature (connected to armature of DC motor) that's y it is called 3 point starter :)
