1. Connecting the power, for the default setting is high voltage protection voltage 270V, low voltage protection voltage 170V and working delay-time 10 seconds. 2. Press the SET key to enter the high voltage setting page, the digital is flashing, press the + or - key to adjust the high voltage protection range. Press the SET key again, it’s enter the next low voltage value setting, the digital is flashes again, press the + or - key to adjust the low voltage protection range. Press the SET key again, the page is entered the delay-time setting, press + or - key to adjust the delay time after the power is recovery. Press the SET again to confirm all data are OK finally. 3. When the applied voltage is in the normal working range, the blue light will be ON; When the product is in the protection state of too high or too low voltage, the red light will be ON, and the power will be cut off automatically; When the product is power off because the instantaneous voltage is too high or too low, delay protection will be opened automatically, and no power output. 4. After the delay-time countdown off, the product to be resume working. Noted: The reset voltage is automatically detected at a set value below or above 10V. ?High-voltage protection: 10V below the original settings recovery; ?Low-voltage protection: 10V above the original settings recovery.