Motor runs for about 10 seconds then trips breaker without any load on it
The start capacitor for the motor is bad or the internal switch isn't shutting off the start capacitor. The start capacitor usually is mounted to the side of the motor in a sheet metal case that has 2 screws. The metal case is usually contoured and likes like a long wart on the side of the motor. Oh, DISCONNECT YOUR MOTOR FROM ALL ELECTRICITY BEFORE DOING ANY OF THIS! I would recommend removing the motor entirely from the saw.
To Check the start capacitor...
Open the metal case on the side of the motor to expose the capacitor. Be carefull here, as you could get a shock! Use a screwdriver with a plastic handle, and while holding the platic handle only, touch the 2 leads of the capacitor together for about 5-10 seconds. This will drain the capacitor of any residual charge.
Disconnect the wires to the capacitor. Connect a multi-meter or resistance/ohm meter to the two leads. If the resistance is 0, then slowly starts to climb (you can reset to 0 using the screwdriver across the leads again) - then the start capacitor is good. If the resistance is infinity or very large, then the capacitor is bad.
I'm betting that your capacitor is good (the motor would have a hard time trying spin if capacitor was bad), then it's the internal switch that shuts off the start capacitor. In my experience, these switches are mechanical and the are centrifical switches - it's like 2 little weights at the end of an arm attached to the motor shaft. The faster the motor spins, the further the weights swing away from the shaft.
I've found that these switches get dirty/corroded or filled with sawdust (when the motor isn't very well sealed), or the lubricating grease dries out. If you're mechanically inclined, I say take the motor apart and clean the switches and re-lubricate them. Adjust as necessary. But you can totally mess them up or have parts from your motor shoot across the shop (some are spring loaded).
Dec 17, 2010 |
Craftsman 10" Table Saw