Glossary of Motor Terms
Number of poles
The number of magnetic poles in the windings or the field system in a DC or AC motor. There must be an even number, so the minimum is 2, then 4, 6, 8, etc. In DC motors and rotating field type AC motors, the number of poles in the field system and that in the armature winding are equal. The figure below shows examples of an inner-rotor 4-pole construction and an outer-rotor 16-pole construction.
