It is an analog-type electronic device developed to govern the movement of the rotation or trolley on construction cranes equipped with motor-retarders.
The NCT112 device acts on the AC voltage of the motor (by choking it when necessary) and on the DC voltage of the retarder to obtain three different working speeds.

With its own outputs, it pilots the two direction remote switches (right and left or far and near) and the parking brake one, as well as a remote control used to exclude the throttle when the maximum voltage value of 400Vac has been reached.
It allows easy adjustment of the micro-speed to be able to adapt it to any type of crane, large or small.

It controls the accelerations and decelerations of the crane arm and trolley with millimeter ramps that automatically adjust to the most varied load and work conditions.
At the start, it gradually increases the motor supply voltage according to a pre-established curve, the result of innumerable practical experiments, in order to minimize the stresses on the structure and mechanics of the crane.

When slowing down, it automatically and appropriately adjusts the tension on the retarder to stop as quickly as possible without stressing the mechanical structure.
Once stopped, it allows you to delay the fall of the parking brake as long as necessary to completely discharge the inertia and avoid swinging of the load.

It safeguards the structure of the crane and all the mechanical parts involved and prolongs their average life by preventing the negative effects of incorrect maneuvers such as sudden reversals of direction.
It reduces starting cues allowing a lower power commitment.