Protection to Micro lathe power supply?

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Dave, the model I posted for a bush DC motor which applies to all DC motors shows the relationship between speed and current. And the highest current occurs at zero rpm. So a fuse designed for motors will disconnect the motor when locked. Consumer product such as a garbage disposal that expect to have a locked rotor have a bimetal thermal circuit switch that is located in the end turns to disconnect the motor, and I believe the water heaters for coffee pots also choose this part. Retro-fitting a motor I agree maybe difficult.
However; there is a reason that consumer companies choose this solution. It would be much easier to mount the device on the motor housing in the connection box or region on the housing. The reason is simple, there is a lag in the temperature rise of the housing and a reduction in the peak temperature if failure of the windings didn't occur, stayed generating heat at the locked current level. It is slow and inaccurate. Temperature measurement is useful to determine with experience what temperature the housing needs to reach before turning on a fuse or breaker tripped motor and the minimum time due to lag.
I would use on the treadmill motor a thermal fuse around 90°C / 200°F . Just use a tubing clamp or wire for thermal fuse to motor. Use wire nuts so change the thermal fuse.
Thermal fuses are found on Amazon, Walmart or a Aplance parts store.


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