Question About Motors

[Jraef]

FYI, most resi fart fans are "universal motors" here is an explanation. https://byjus.com/physics/universal-motor/#:~:text=When fed with an AC,are in the same phase.

Nooo… Universal motors are used on countertop appliances and tools, but never on bathroom fans. They have brushes and would not last in a moisture rich environment.

Shaded pole motors on these fans, and the bearings get loaded up with dust. Take it out, give it a good cleaning and oil the bearings if you can.

 

[garbo]

FYI, most resi fart fans are "universal motors" here is an explanation. https://byjus.com/physics/universal-motor/#:~:text=When fed with an AC,are in the same phase.

Good old bullet proof universal motors. Only motor type that I ever saw that can operate o. AC or DC. My dad had a 3/8" hand drill from the 1950's that could run on AC or DC. Don't think it would be practical for a bathroom exhaust fan because they usually run over 8,000 RPM.

 

[drcampbell]

Good old bullet proof universal motors. Only motor type that I ever saw that can operate o. AC or DC. My dad had a 3/8" hand drill from the 1950's that could run on AC or DC. Don't think it would be practical for a bathroom exhaust fan because they usually run over 8,000 RPM.

They also need new brushes every few hundred hours, and new commutators every few thousand.
If there's no filter in front of it, the brush arcing might start a hair/dust/crud fire in the exhaust ducting ... or directly into the attic, whee installed that way.