Planer will just shut off?

[Mark W Pugh]

I have an old 15" Buffalo planer from the 80's. Every now and then, during planing, the planer will shut down. I'm not bogging it down, it just quits. I will lower the table, take out the board, raise the table and restart it. I don't have to reset anything. The switch is magnetically actuated.

My thoughts go to the switch. Does anyone know is there an overload circuit on these switches? Any ideas, or suggestions, where I should start trouble shooting?

Thanks

[Jason White]

Thermal overload protector in the motor itself? My bandsaw motor has one. There's a red reset switch on the motor. Might need to take the motor apart and blow all the dust and chips out with a compressor.

[Steve Baumgartner]

I am not familiar with that specific machine, but I'd agree that it sounds like a thermal or current overload protector. Since it restarts without pushing a reset, it must be automatic. If you open up the box with the mag controls, you can see if there is an overload as well as the main contactor relay. Most overload protectors have adjustments on them that are supposed to match the full load of the motor.

[Lee Schierer]

If the thermal overload in the motor tripped it would take several minutes for it to cool down enough to reset either manually or automatically. I suspect there is a problem with the magnetic contactor holding circuit. Perhaps the contacts are dirty or the vibration is causing the contactor to open. A loose wire would also cause the planer to stop in mid cut.

[peter gagliardi]

Open up the magnetic contractor box, and blow it out. Over the years, dust can accumulate, and cause poor contact. The result of poor contact will start the contacts arcing, resulting in a pitted contact surface, resulting in less and less magnetic pull holding the contacts in the run position. So, inspect the contact faces, and possibly flatten/clean them off with a scraper, file, or emery paper.