What type of interlock uses a cam to prevent simultaneous closure of forward and reverse contactors?

A mechanical interlock utilizes physical components, such as a cam, to ensure that only one contactor can be closed at a time, thus preventing the simultaneous operation of forward and reverse settings in motor controls. This system works by creating a direct physical connection or restriction, such as a cam that physically blocks the path of one contactor when the other is engaged.

The operation of contactors is critical in motor control circuits, as running a motor in both forward and reverse simultaneously can lead to severe damage. Mechanical interlocks provide a reliable means of ensuring safety by using straightforward mechanical principles to establish interdependence between the contactors.

In contrast, electrical interlocks rely on circuit logic to achieve a similar result, while pneumatic and hydraulic interlocks generally involve the control of fluids and may not be applicable in this specific context where a direct mechanical action is needed to prevent contact closure. Thus, the use of a mechanical interlock with a cam is the most effective way to ensure that forward and reverse operations are never engaged at the same time.