DC Shunt Motor & DC Series Motor

DC Shunt Motor

In the DC Shunt Motor, the armature winding and field winding are connected in parallel and voltage across it, equal to supply voltage.

DC Series Motor

In the DC Series Motor, the armature winding and field winding are connected in series and voltage across it, equal to supply voltage.

Compare DC Shunt Motor and DC Series Motor

Series field winding	Shunt field winding
The armature winding is series with the field winding	The armature winding is parallel with the shunt field winding.
As the series field winding is connected in series with the armature winding, the series field carries same current as that of armature winding.	As the shunt field winding is connected in parallel with the armature winding, the voltage across shunt field winding is same as the armature winding.
The series winding is designed with few turns of thick wires.	The shunt field winding is designed with large number of turns having thin wires.
The resistance of the series field winding is very low.	The resistance of the shunt field winding is very high.
The torque is directly proportional to square of the armature current. T α ΦI_a As Φ α I_a T α I_a² The series motor would draw only 1.41 times full load current for the same amount of torque. ( As t α I_a² )	The torque is directly proportional to the armature current. T α ΦI_a As Φ is almost constant T α I_a If twice the full load torque required at start, the shunt motor draws the twice the full load current. ( As t α I_a )
The starting torque develop by series motor is high as compared to shunt motor for same amount of armature current.	The starting torque develop by shunt motor is low as compared to series motor for same amount of armature current.
A series motor respond by decreasing its speed with small increase in current for a given load torque.	A shunt motor holds its speed nearly constant with large increase in input current for same amount of load torque.
Variable speed motor	Constant speed motor
Applications : Hoists , Cranes , Trolley cars ,Conveyors, Electric locomotives	Applications : Lathes , Centrifugal pump , Blowers, Machine tools , Printing process , Spinning machines, Reciprocating pump