Voltage measuring relay For failing to meet and for exceeding the threshold value of single-phased voltages, operating ranges AC/DC: 0.5 to 500 V, Curve shape: sine, square, triangle, 10 time domains: non-delayed, 0.1 s to 3 h for the operate time delay, Frequency range of the measured variable from 45 to 400 Hz, Multifunction: Operating or rest current principle, hysteresis 3 % or 10 % of the target value