1. This relay can monitor own working voltage (true RMS measurement).2. 8 kinds of adjustable rated voltage.3. Voltage measurement accuracy is not more than 1%.4. Relay working status is indicated by LED indicators.5. With super small volume, this relay can be mounted on 35mm DIN rail.Application: Equipment protection and control(tower crane, elevator, agriculture equipment, refrigerated trucks); Protect equipment from reverse running; Normal/emergency power supply switch; Protect against phase failure of a dynamic load.Function: Monitor L-L voltage (3-phase 3-wire system)Monitoring terminal: L1-L2-L3Power: L1-L2Rated working voltage: 220-230-240-380-400-415-440-460(P-P)Rated power frequency: 45Hz-65HzMeasuring range: 176V-552VVoltage threshold range: 2%-20% (rated voltage)Voltage fixed lag rate: 2%Voltage measurement error: less than equal 1%Power-on delay time: 0.5sKnob setting accuracy: 10%Reset time: 1sTemperature fluctuation error: 0.05%/C, at=20COutput: 1 x SPDT; 10A/ AC1; 250VAC/24VDCMinimum switching power: 500mWOvervoltage: 2%-20%Undervoltage: -20%-2%Action delay time: 0.1-10s adjustablePhase sequence protection: YesPhase failure protection: YesPower indicator: Green LEDOutput relay indication: Red LEDMechanical life: 1x107Mounting : 35mm DIN rail mountingMount altitude: less than equal 2000mWeight: . 78g/2.7ozsize:95*18*64mmcolour:whiteMaterial:plasticPackage Contents:1 * Voltage Monitoring Relay1 * InstructionsOnly the above package content, other products are not included.Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.