Mains powered fractional HP motor winding.

[#12]

Just a curiosity, but I was recycling (scrapping) some mains powered fan motors (PSC) and saw that they have 36 "shapes" in the stator? laminations (or is that called the "field"?). Thirty six scooped out places and 36 of what looks like magnetic poles. This made me wonder if this is a standard shape so that "any" speed motor can be wound on the same core. Speed = 3600 (in the US) divided by the number of poles?

Next question: For a 3 speed motor, do they wind the stator so the motor has 3 magnetic field arrangements or do they just use longer windings to impede the current to make the motor run slower? I've noticed that 3 speed motors have less horsepower available when you use a lower speed winding.

 

[tcmtech]

Thats a standard design for most AC motors except shaded pole types.

Variable or multi speed design can be done by either using extra windings on each pole to limit the current and thus regulate the speed by limiting the torque such as in fan motors or it can be done by using multiple windings each with their own pole configurations.

 

[#12]

OK. The answer is: yes.
Various manufacturers use these standard core laminations and wind motors both ways, depending on their intended use.
Thank you.

 

[KeepItSimpleStupid]

PSC motors like ceiling fans and either tap the winding with a single cap or use multiple caps. The windings will have a slight differenece in reistance.