Answer / sagar

The armature of a DC shunt motor is connected to the external circuit via a commutator which can convert ac to dc as well as dc to ac. So AC supplied across the armature will be converted to DC so, current flowing in armature will be DC. But there will be an AC applied across the field winding, hence the field will vary with time from 0 value to max value. The machine will rotate but with serious vibrations induced in it, bcoz the torque will vary from 0 to a max value and that also 50-60 times per sec depending on frequency applied. (NB: don't compare this situation with synchronous m/c as there will b no rotating mf in this case)

Answer / shekhar

NO,in dc motors when ac given to the armature IT CONVERTS IT INTO DC and produces a stationary armature magnetic field,if ac is aplied o the shunt field it will produce alternating field which will produce torque in opposite torque in alternate half cycles so avg. torque will b zero.

Answer / vishwa theja c

yes, in dc motor commutator produces opposite poles and alternating magnetic field using dc. but on using ac this magnetic reversals is very high and frequent causes sparking at brushes. so it is not satisfactory and danger.

Answer / venkatesh

no.
as field winding is shunted with armature ac voltage is
applied across field winding.
thus the resulting avarage flux is zero.

Answer / manoj

yes it would operate similar to a dc supply but the
difference would be that it will move with variable speed.
since because in ac as the polarity changes polarity of
field flux and direction of current in armature winding also
changes hence the direction of torque remains same as it
would be in case of dc.

Answer / vishwa theja c

yes, as dc shunt motor commutator converts dc to ac supply to windings, but there will be sparking at brushes as ac changes it's polarity frequently so it is not satisfactory operation, and motor gets heated easily this may leads to failure of insulation.

Answer / deepak tyagi

dc shunt motor can not operate on ac because field winding
have the ac supply while the rotor winding have the dc
supply due the commutator because its function is to
convert the ac to dc or dc to ac. torque angle mean angle
between the armature mmf and field mmf will be time
dependent mean average torque will be zero.

Answer / chandra

yes,DC shunt motor can be operated with AC supply.When we
apply AC voltage to the armature,the DC shunt motor is
similar to a Synchronous generator.So,it works like a
synchronous generator.

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