The MT190 is a Circuit Breaker Finder system that operates on energized circuits, consists of a Transmitter, which plugs into the socket on the circuit you wish to isolate and a Receiver Scanner. The Transmitter sends signals along the cable to the distribution board, the operator simply runs the Receiver Scanner along the circuit breakers or fuses, and the scanner will automatically identify the correct breaker by means of a green LED and a continuous buzzer tone. An added feature is the convenient chart printed on the Transmitter that helps determine the wiring condition of the socket outlet, based on the LED lights results. Conditions indicated are Correct Wiring, Open Ground, Reverse Polarity, Open Live, Open Neutral and reverse Live and Ground. There is also a 30mA RCD test function built into the MT190 Transmitter.