The basic principle behind the machine is not difficult to grasp: For applications with long cycle times the drive power of the pump motor is adjusted to match the reduced energy requirements of the machine during phases when none of the hydraulic axes are active. For example, during long cooling and curing times, the speed, and consequently the output of the pump motor, are adjusted to match the actual amount of energy required, rather than constantly operating inefficiently at the rated speed. Once this “rest phase“ is completed, if full output is again required, then the rev speed of the AC asynchronous motor can be increased to its rated speed, thereby bringing it up to its rated capacity. Built into the machine control system is a regulating and control unit, which the AES uses to constantly check the current output requirement. An infinitely variable frequency converter adjusts the speed of the electric motor to suit the actual output required. Consequently, even at low loads, the motor still operates with optimum efficiency and correspondingly low energy consumption.

It makes sense to use the AES with applications, where “rest phases“ such as cooling and lag times take up a considerable proportion of the entire cycle. In such cases efficient energy savings can be made by reducing the rev speed. An added bonus is the reduction in noise emitted by the machine when operated at lower rev speeds. In addition, highly efficient drives minimise wear and tear and produce less excess heat, with the result that energy can also be saved when operating the cooling systems.