Sta-rite pool pump humming.

[Poconos]

Hi Mikey and welcome to the forum.
It sounds like it was a loud hum and the internal thermal switch cut out. After it cools it would try again. Now what caused the hum. First thing I would think of would be the starter capacitor shorting and causing a LOUD hum but when they short, they don't fix themselves. Besides, I think the thermal cutout would cut in less than 15 seconds. I'm thinking the centrifugal starter switch contacts are cruddy and what you heard was a low level hum. Lots of motors have this problem especially when they're out in the environment and are older. If this is the cause it's an easy fix if you want to dig into it. Kill the power and pull the back cover where the wires go in. You should see a set of contacts that are part of the centrifugal switch mechanism. This switch opens when the motor is up to speed and closes when stopped. It powers a starting winding to get the motor going. If the contacts are crummy the starter winding is not powered and the motor will just hum. Take some fine sandpaper, 600 grit, and clean the contacts. No need to grind away, just a light dressing. I have no idea how many motors were saved over the years by just cleaning these contacts. If the repair guy tries to sell you another pump, tell him you'll think about it and get back to us. Since it does run normally, most of the time, it probably is not a major, read $$$, problem.
Al
Edit: I FINALLY figured how to post pics. Kind of convoluted compared to the way it used to be but it seems to work.

This is a pic of the back end of my Superpump. The contacts are the inverted V.



As you can see the pic was taken in 2004. Pump installed 1997 and still going strong. It's in a poolhouse and have only had to retorque some bolts almost every spring.


Mikey, let me know is you can view the pic. Think you should be able to.
Al