Features: 1. This relay can monitor its own working voltage (true RMS measurement). 2. 8 types of adjustable rated voltage. 3. Voltage measurement accuracy is no more than 1%. 4. The relay's working status is indicated by LED indicators. 5. With a super small volume, this relay can be mounted on a 35mm DIN rail. 6. Application: Equipment protection and control (tower crane, elevator, agricultural equipment, refrigerated trucks); Protect equipment from reverse running; Normal/emergency power supply switch; Protect against phase failure of a dynamic load. Specification: Function: Monitor L-N voltage (3-phase 4-wire system) Monitoring terminal: L1-L2-L3-N Power: L1-N Rated working voltage: 127-132-138-220-230-240-254-265 (P-N) Rated power frequency: 45Hz-65Hz Measuring range: 101V-318V Voltage threshold range: 2%-20% (rated voltage) Fixed voltage delay rate: 2% Voltage measurement error: 1% Power-on delay time: 0.5s Button setting accuracy: 10% Reset time: 1s Temperature fluctuation error: 0.05%/C, at=20C Output: 1 x SPDT; 10A/ AC1; 250VAC/24VDC Minimum switching power: 500mW Overvoltage: 2%-20% Undervoltage: -20%-2% Unbalanced voltage: 8% Action delay time: 0.1-10s adjustable Phase sequence protection: Yes Phase failure protection: Yes Power indicator: Green LED Output relay indication: Red LED Mechanical life: 1x107 Mounting method: 35mm DIN rail mounting Mounting height: 2000m Weight: Approx. 76g/2.7oz Package List: 1 * Voltage Monitoring Relay