About the meaning of the output input button. The function is to change the display. Press one time it will show input voltage and press another time it will show output voltage.
Delay protection – 180s delay after starting. When you press this button, stabilizer will start to work in 6s. Delay is to protect the machine from the damage caused by excessive current when start the machine.
Power on the regulator first, wait 180 seconds, then connect your appliance, if you don’t want to wait, press the delay switch, then you can see the current input or output voltage value on the display, press output input switch to switch the display.