"3 phase RMS voltage protection relay -Monitors: Over / Under Voltage, Over / Under Frequency, Phase asymmetry, Phase failure, Phase sequence & Neutral loss -Accuracy: ± 1% of Voltage, ± 0.3Hz -Measuring range : 160 to 520V depending on Network selection -Supply Voltage : 85 to 270V AC/DC -CE and RoHS Certified"