If it the same as the LatheMaster, there are a couple of interlocks, one on the swing guard and one on the cover, I do not believe there is an overload per se.
The start button is a bit 'Mickey Mouse' as what you actually do is push the armature of the start relay closed, which then latches itself in until a stop button is pushed.
The click you can hear is probabally the relay releasing, any of the above interlocks will cause it to drop out.
Al.
CNC, Mechatronics Integration and Custom Machine Design
“Logic will get you from A to B. Imagination will take you everywhere.”
Albert E.