Features 1、Working Principle: When the main power supply fails or the voltage is abnormal, the load is automatically transferred from the main to the backup power supply to ensure uninterrupted power supply. After the main power supply is resumed, ATS will automatically transfer the load back to the main power supply. 2、Flexible Setting: This 3 phase automatic changeover switch allows you to freely prioritize mains power, generators, and inverters. The voltage threshold for switching can be set, so it will automatically switch when undervoltage or overvoltage occurs. The switching speed setting range is 1‑600s, with a default of 30s. 3、Parameter Adjustment: Provides stable switching to prevent power fluctuations or interference. The conversion time, reset time, overvoltage or undervoltage guard, and overcurrent guard parameters can all be adjusted within the specified range. 4、Flame Retardant PC: The automatic transfer switch housing is made of fireproof PC material, which is secure and flame retardant. Featuring high sensitivity, accurate measurement, and low heat generation, you can use it with confidence. 5、Wide Application: This 3 phase 4 wire automatic transfer switch is widely applied in electric system that require continuous and stable power supply, including commercial and industrial buildings, medical facilities, data centers, base stations, etc. Specification Item Type: Automatic Transfer Switch Material: Flame Retardant PC Power Terminals: N, L1, L2, L3 Automatic Reclosure Delay (Ton): 1-600s Return Priority Phase Delay: 1-600s Switching Delay to Reserve Phase: <0.2s Voltage Lag: 5V Overvoltage Trip Delay: 0.1s; ≥350V: 0.02s Undervoltage Trip Delay: 0.1s; ≥350V: 0.02s Voltage Accuracy: <1% Maximum Working Phase Voltage: 350V Rated Working Current: 63A Maximum Working Current: 80A Pollution Grade: 3 Altitude: ≤2000m Ambient Temperature: -25-50℃ Relative Humidity: ≤50% at 40℃ (non condensing) Applicable Wire Size: 0.5mm²-1mm² Installation: 35mm Standard Guide Rail Size: Approx. 90 x 66 x 95mm / 3.5 x 2.6 x 3.7in Package List 1 x Automatic Transfer Switch 1 x User Manual