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AssuredElectrical, Master Electrician
Category: Electrical
Satisfied Customers: 4241
Experience:  Contractor-42+ Years in the ElectricalTrade
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Connect speed controller to 5HP electric Harbor Freight

Customer Question

OK I have a .5 HP electric motor ITEM 67839 on Harbor Freight Website. My main goal is to connect it to a Speed controller and connect it to an outlet. I need about 20 rpm. Have already tried connecting Harbor Freights router speed controller and had no success. I need to build or do something today which I can build with materials at hardware stores or maybe there is something I can buy that I don't know of.

Please help Motor specifics: Name 1/2 HP General Purpose Electric Motor SKU 67839 Brand Smith + Jones Amperage (amps) 8.5/4.25 Application blowers, sanders, saws, conveyor belts and benchtop tools Frequency (Hz) 60 Horsepower (hp) 1/2 Maximum speed (rpm) 1800 RPM Open drip proof housing (y/n) Yes Phase Single Rigid base (y/n) Yes Service factor 1.0 Shaft rotation direction CW/CCW Shipping Weight 27.15 lb.

Submitted: 1 year ago.
Category: Electrical
Expert:  Steve G. replied 1 year ago.

Hello there and welcome to Just Answer.

I need to gather some more information from you in order to help.

Do you actually have the motor or are you just thinking of buying it?

Customer: replied 1 year ago.
I actually have it
Expert:  AssuredElectrical replied 1 year ago.


It may not be the answer you were hoping to receive, I can understand.

But, the previous expert is spot on with the situation, there is no way to achieve a speed control on the motor you have in hand.

Even if there was a controller for that type of motor, it is a capacitor start and most likely has a centrifugal switch inside the motor.

This switch cuts out the capacitor when the motor reaches approx, 75% of its rated speed and then the motor runs on the run windings.

So, even if you had a speed controller to work on the single phase motor, you would have to run it at 75% speed just to get it switch from start to run. .

The motor is not designed for controlling the speed electrically.

Best to get a 1/2 hp 20 rpm gear motor for the application and it would run at 20 rpm output all the time normally through the gearbox.

Used these on swimming pool covers and other special applications

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