System consisting of a plastics-processing machine, in particular an injection moulding machine, and a peripheral unit, in particular a handling device, wherein the peripheral unit has at least one electrical consumer (4, 5, 6), wherein the plastics-processing machine has at least one electrical consumer and wherein the peripheral unit is connected to an electric AC grid in order to be supplied with electrical energy, wherein at least one of the electrical consumers (4, 5, 6) of the peripheral unit is also designed for generator operation to convert kinetic energy to electrical energy, wherein at least one electrical consumer of the plastics-processing machine can be electrically connected to one of the electrical consumers (4, 5, 6) of the peripheral unit that operate by way of generator and wherein the electric AC grid is connected to a DC intermediate circuit via a rectifier, wherein at least some of the electrical consumers (4, 5, 6, 7) of the peripheral unit and of the plastics-processing machine are electrically connected to the DC intermediate circuit and can be supplied with electrical energy therefrom and wherein at least some of the electrical consumers (4, 5, 6) of the peripheral unit that are formed for generator operation are electrically connected to the DC intermediate circuit to feed in electrical energy generated by way of generator, wherein at least one electrical consumer of the plastics-processing machine is electrically coupled to the DC intermediate circuit, wherein the energy draw of the electrical consumer of the plastics-processing machine from the DC intermediate circuit is controlled by means of a semiconductor switching element (16', 16'', 16'''), wherein the electrical consumer of the plastics-processing machine is preferably a heating element of the plastics-processing machine, wherein the semiconductor switching element (16', 16'', 16''') is connected to at least one sensor for detecting an operating parameter of the electrical consumer of the plastics-processing machine, wherein the semiconductor switching element (16', 16'', 16''') comprises a first comparator for comparing the value of the operating parameter measured by the sensor with a prescribed value for the operating parameter, wherein the semiconductor switching element (16', 16'', 16''') comprises a first computation unit for ascertaining a required switch-on period (ED T) for the electrical consumer of the plastics-processing machine for satisfying the prescribed value for the operating parameter, wherein the semiconductor switching element (16', 16'', 16''') comprises a second comparator for comparing the value of the intermediate circuit voltage (U ZK) measured by a voltmeter with a prescribed maximum value for the intermediate circuit voltage (U ZKmax) and wherein the semiconductor switching element (16', 16'', 16''') comprises a second computation unit for ascertaining a required switch-on period (ED UZK) for the electrical consumer of the plastics-processing machine for satisfying the maximum value for the intermediate circuit voltage (U ZK), characterized in that the first and the second computation unit (20, 22) are connected to a maximum value former, which is configured to ascertain the greater of the two values for the switch-on period (ED T, ED UZK), wherein the maximum value former is designed to prescribe a prescribed switch-on period for the electrical consumer of the plastics-processing machine.