Contact blocks N/C and N/O are slow break when they are associated with a pushbutton or a selector switch because in this case the speed of the contact opening is directly linked to the operating speed of the operator.

But when they are associated with an emergency stop with trigger action, they have quick break (Snap Action). Indeed, the speed of the contact opening is in this case independant from the operating speed of the operator. In a first time when you push the mushroom, the plunger of the contact block does not move, you only stock mechanical energy. You do this until this energy is released to operate the plunger. In this case speed of the contact opening is very quick

Released for:Schneider Electric USA