Electric motor problem

[Eric in IL]

This motor is a 110 volt, 1/3 hp that is used on a grain bin spreader hanging from the roof. This fall it only worked for a couple loads. Then it would just hum when switched on.

I removed the motor a week ago. The capacitor looked ok visually so I took it to a motor shop yesterday. He tested the capacitor as being good. Hooked it to power and it started fine. When it coasted to a stop I heard a click making me think it has a mechanical starting switch.

I told the shop owner to put in some new bearings and take a good look at the switch. This motor starts or cycles 3 times a minute when it is in use.

Do you think I should just have him replace the starter switch ?

 

[Geo-TH,In]

Replace the centrifugal switch

 

[Russ from MN]

Maybe if he just cleans it well it will be fine for awhile, but that sounds like a dusty environment, it probably just had dust between the points. It's probably not an explosion proof motor, it maybe should be. They make load sensitive remote starting switches, maybe that would be a solution.

 

[guido]

Eric in IL,

With that many cycles on and off you NEED to change the starting switch,

Guido.

 

[Steve@Advance]

Is it financially practical to have a 1/3 HP motor repaired? Motor shops around here won't even look at a motor that small unless it's something special.

Starting a cap start motor that often is going to greatly shorten the life.

If you replace it, be sure to get a TEFC (totally enclosed fan cooled) motor. They are not explosion proof but are enclosed for dust resistance.

If the starting/stopping continues to be a problem, another solution would be to replace it with a 3 phase TEFC motor and drive it from a VFD controller. A 3 phase has no internal circuitry, so it doesn't mind starting and stopping or breathing dust. The VFD is all solid state, no contacts to wear and arc.

 

[miangus]

Yes replace the switch. This is a good place for a joke/quiz I played on my kids just recently. You guys will all know the answer, they didn't. I was using a small auger to auger corn into the grinder. When I started it the cap smoked the connection so I had to start the motor manually. The auger ran but no corn came out, why.

 

[showcrop]

Another option for a frequently started motor is an electronic start switch. We used to service a lot of machines that started 5,000 times per month. The OEM switches were needing replaced way to often. The owner of the motor repair shop told us about the solid state switches. The brand that he used was Sinpac. The installed cost was approx. the same as a new motor but now the repaired motor was better than ten new ones, and now our techs were staying home with their families in the evenings.

 

[47fivewindow]

Maybe you manually started it in the wrong direction?