1-30
MOTOR REACTION is caused by the magnetic field that is set up in the armature. It tends to
oppose the rotation of the armature, due to the attraction and repulsion forces between the armature field
and the main field.
ARMATURE LOSSES in dc generator armatures affect the outputs. These losses are as follows:
1. Copper losses are simply 12R (heat) losses caused by current flowing through the resistance of
the armature windings.
2. Eddy currents are induced in core material and cause heat.
3. Hysteresis losses occur due to the rapidly changing magnetic fields in the armature, resulting in
heat.
