Intelligent Neutral and Live Wire Identification Adjust the reducer position until the indicator light turns off, indicating neutral. The red indicator light stays on, indicating the presence of a live wire. Live Wire Detection Set the reducer position to 0. When the red indicator light stays on when the tester is inserted into the socket, this indicates the presence of a live wire. Neutral Wire Detection Set the reducer position to 0. When the indicator light does not turn on when the tester is inserted into the socket, this indicates the presence of a neutral wire. Three adjustable reducer positions. Explanation of the reducer position. Adjust the appropriate reducer position according to the environment and test needs. Gear H (High Induction) Non-contact inductive detection of AC voltage L (Low Induction) Gear Line break detection/Identification of neutral and live wires Gear position (Direct contact) Battery self-test/Continuity test Break point detection Troubleshooting Set the gear position to L or H. Test the line with the tester. When the green light does not turn on and the buzzer stops, the break point is located.