Answer / ritesh pokarna

because in three pt starter,there are three p.t which are
as follows
1)Line:-(L)
2)Field:-(f)
3)Armature:-(A)
above three pt act in dc motor&remaining starting
resistance is connected in series with armature.

Answer / atul dattatray ahirrao

this is called as three point starter because three points L,A and F are brought out for the external connection.
Point L:it is the line terminal and should be connected to the dc supply.
point A:it is to be connected to the armature winding.
point F:it is to be connected to the feild winding.

Answer / vignesh

it has three terminals l,f,a namely

l=line current
f=field current
a=amruture
it is connected dc motors .it is used shunt motors.it
protocts overload volts ect.

Answer / hima teja

3 POINT DC STARTER
3 point DC starter is a unit intended to limit the starting current in a DC circuit. This starter is a must for any DC motor applications. This starter has three functions.
(a) To provide series resistance in a DC circuit when this starter is in START position. I.e. In STARTposition full resistance is included, and is reduced to zero ohms when the handle is moved to ON position, in discrete steps. The starter is held in ON position by an electromagnet. At this ON position the DC circuit gets its full current from the DC Rectifier unit. In the case of a DC motor, this is
connected in series with the armature circuit, to limit the starting current and eventually this resistance is CUTOUT, from the circuit. There by enabling the motor to run at it’s full armature current. Therefore this starter acts as a first order protection circuit, in between a DC rectifier unit and the DC circuit.
(b) No Volt Coil (NVC) – This is normally connected to Field circuit in a DC motor. In case of a failure in current in this circuit, for any reason, namely accidental tripping, or unintentional break in field circuit, this coil will provide a signal to the electromechanically held arm (handle) to release, and the starter is switched to OFF position, thereby providing safety to the system.
(c) Over Load (OL) release switch – This is connected in series with the armature circuit. In case of current beyond the rated current of this coil in the circuit, this automatically trips the electromagnet, which is holding the handle in ON position. Thereby tripping the starter from being over loaded

Answer / madhu kavlekar

because of armiture wdg has less resistance if total
voltage is given directly to a arm. wdg.the arm. may
damage, so the three point startor is used to reduce the
damage,by decreasing the resistance and increasing the
voltage slowly.

Answer / aarif ashraf

Bcoz it has
3 points(terminals)
L,A, nd F connected to
the motor to save it
from damages like
short circuiting etc.

Answer / s.balamurugan

In basically 3 point starter has used in dc motor because
in dc motor design field windings are connected in stator
and armature windings are placed in rotor.so at starting we
can use 3 point starter to reduce the starting curent and to
excite the field and to produce emf in rotor thus emf oppose
the dc supply is called back emf........

Answer / richa

3 Point Starter is a device whose main function is starting and maintaining the speed of the DC shunt motor. it is called three point starteras it has three terminals.
L is the Line terminal, connected to positive supply.
A is the armature terminal and connected to the armature windings.
F is the field terminal and connected to the field terminal windings.
for more information on 3 point starter see here http://circuitglobe.com/3-point-starter.html

Answer / vineet singh

There is no solid reason to say that, it is called three point
Starter because it has major component supply ,field winding ,
And armature coil.....I think so..

Answer / kushal kumar

Bcz it has three points. L. F A. Which are connected to line , field,armature respectively..

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