Method for identifying the presence of a sufficient input-side supply voltage (V mains ) on an operating device , a supply voltage (V mains ) supplied to the operating device being rectified and subsequently compared with three reference voltages (Vrefl, Vref2, Vref3), and, for the purpose of identifying the presence of a sufficient input-side supply voltage (V mains ), the presence of an input-side supply voltage (V mains ) only being determined if the rectified supply voltage exceeds at least one of the three reference voltages (Vrefl, Vref2, Vref3) for a predefined period of time in a time measurement, characterized in that the peak value of the supplied supply voltage (V mains ) or of the rectified supply voltage is additionally detected, and in that the presence of a sufficient input-side supply voltage (V mains ) is only determined if i. the presence of a supply voltage is determined on the basis of the comparison of the rectified supply voltage with the three reference voltages (Vrefl, Vref2, Vref3); and ii. the peak value satisfies a predefined condition whereby the peak value exceeds a predefined reference value; the type of the available supply voltage (V mains ) first being determined on the basis of the comparison of the rectified supply voltage with the three reference voltages (Vref1, Vref2, Vref3), and in that the peak value is compared with the predefined reference value, the predefined reference value being dependent on the previously determined type of the available supply voltage (V mains ). a supply voltage (V mains ) supplied to the operating device being rectified and subsequently compared with three reference voltages (Vrefl, Vref2, Vref3), and, for the purpose of identifying the presence of a sufficient input-side supply voltage (V mains ), the presence of an input-side supply voltage (V mains ) only being determined if the rectified supply voltage exceeds at least one of the three reference voltages (Vrefl, Vref2, Vref3) for a predefined period of time in a time measurement, characterized in that the peak value of the supplied supply voltage (V mains ) or of the rectified supply voltage is additionally detected, and in that the presence of a sufficient input-side supply voltage (V mains ) is only determined if i. the presence of a supply voltage is determined on the basis of the comparison of the rectified supply voltage with the three reference voltages (Vrefl, Vref2, Vref3); and ii. the peak value satisfies a predefined condition whereby the peak value exceeds a predefined reference value; i. the presence of a supply voltage is determined on the basis of the comparison of the rectified supply voltage with the three reference voltages (Vrefl, Vref2, Vref3); and ii. the peak value satisfies a predefined condition whereby the peak value exceeds a predefined reference value; the type of the available supply voltage (V mains ) first being determined on the basis of the comparison of the rectified supply voltage with the three reference voltages (Vref1, Vref2, Vref3), and in that the peak value is compared with the predefined reference value, the predefined reference value being dependent on the previously determined type of the available supply voltage (V mains ). <EOS>