There are two main losses.
a. Copper losses or electrical losses.
b. Stray losses or rotational losses or constant losses.
Copper losses includes following losses
a. Armature copper losses (Ia 2 ra).
b. Field copper losses (Ise 2 rse) or (Ish 2 rsh).
c. Losses in brush.
Stray losses are as follows
a. Magnetic losses (Iron loss or core loss).
b. Mechanical losses.
