VFD question

Well why didn't you _say_ it was a mechanical logic switch?

I think the vote goes to VFDs with braking resistors if you have to do many quick stops. The article on pluggers noted that they heat up quickly if you do much repetition.

Depending on the motor plugging may be OK. For example, my Bridgeport mill motor has "Tropical Insulation" according to the nameplate. So I guess that means it can tolerate heat better. There have been many days over the years where I plug reversed the motor all day power tapping holes and the motor never ran too hot. I have owned this mill since 1981. If a motor can be kept cool enough then plugging will be fine. Just adding a fan might be good enough and loads cheaper than a VFD with a resistor bank. The switch on my mill is still the original with the original contacts. It has been used to plug the motor thousands of times. Eric