answersLogoWhite

0

The only explanation to that is given by the presence of back emf Eb, which plays a critical role in governing the operation of the motor. The back emf, develops as the motor armature starts to rotate in presence of the magnetic field, by generating action and counters the supply voltage. This also essentially means, that the back emf at the starting is zero, and develops gradually as the motor gathers speed.

The general motor emf equation E = Eb + Ia.Ra,

at starting is modified to E = Ia.Ra as at starting Eb = 0.

User Avatar

Wiki User

12y ago

What else can I help you with?

Related Questions

What is use of two point starter in electrical machines?

A two-point starter is used to control the starting of electrical machines, such as DC motors. It helps limit the initial current surge during the starting process by gradually increasing the voltage applied to the motor through the use of resistance. This protects the motor's windings and prevents damage due to high inrush current.


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 :)


Is 4 point starter used to start and control the speed of dc shunt motor with armature resistance control?

yes


Which motor is used for starting engine?

Er... a Starter Motor?


Can a starter used for 5 hp 3 phase motor be used for 7.5 hp 3 phase motor?

No, you cannot use a starter rated for a 5 hp motor with a 7.5 hp motor. The starter needs to be matched to the motor's horsepower rating to ensure proper protection and operation. Using an undersized starter can lead to overheating and premature failure of the motor. It is recommended to use a starter specifically designed for a 7.5 hp motor.


Can a voltmeter be used to measure voltage in and out of a starter motor?

Voltage flow into a starter motor, never out of it. Use the voltmeter to measure the voltage at the starter motor before starting to crank and then whilst it is cranking. (Before cranking, the voltage appears across the starter motor relay only.)


A motor starter will have a set of auxiliary contacts which is used to provide a?

Feedback to a control circuit that the motor starter has closed or opened its contacts as commanded.


Why use link in star contactor?

The link in the star contactor is used to form the star point of three of the motor leads. On most star wound motors the star point is inside the motor windings. On a motor that can be used for star delta starting it is a six wire motor. The star point winding depends on the contactor to tie the coil ends together externally in the control panel of the star delta starter.


What type of motor is used in a starter motor?

None, it is an electric motor In fact, most cars have SERIES connected starter motors - an electric motor where the field windings (the ones that are fitted to the case of the machine and don't move) have the same current flowing in them that the armature (the rotating part of the motor) has. A series motor has very high starting torque, so it's ideal for getting a large lump of scrap metal turning over, but it has poor running (high speed) torque and poor speed control. (Speed control is so poor that if you spin up a starter motor without a load, it may over-speed and possibly throw its windings out of the armature!) Some starter motors use permanent magnets for the field system - these magnets are quite powerful and give the motor good starting torque, and magnet systems are smaller than the series coil systems, and make the starter motor a bit lighter and cheaper. These motors also have a lower top speed at no load, too.


Where on a motor vehicle would brass be used?

Brass bushings inside the electric starter motor.


How the Operation of direct online Starter?

A direct line starter is a simple motor starter used to power electric machines. It works by coupling the motor to the power supply directly at full function.


What DC motor is used for traction?

dc series motor is used for traction...