Digital ammeters are designed to monitor the AC current value drawn by the loads continuously. If the current value drawn by the load is below 5A (I), you can connect the current input (k) and current output (I) terminals directly without current transformer. When the device is energized,firstly you need to enter the current transformer value in order to see the current values accurately. Press the menu button to enter the current transformer value and enter the value by pressing the Up or Down buttons. Then, the value is saved when you pressed the menu button and the current drawn by the load is shown on the display. Default value is set to 50/5A. If you make direct connection without current transformer under 5A, you need to ensure that the current transformer value is 5.