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Operating Principle
5. Operating Principle
The Cable Locator consists of a transmitter and a receiver. It is a portable instrument that can be used to
detect or trace conductors.
The signal generated by the transmitter is made of a modulated current, generating an electro-magnetic field
around a conductor. See figure 1. This electro-magnetic field induces a voltage within the receiving coil. The
induced voltage is amplified, decoded and converted to the original signal by the receiver and displayed on
the screen. The process operates on the principle of a closed current circuit.
Figure 1:
5.1 Location in complete circuits
5.1.1 Single pole method
Connect the transmitter to only one conductor. In this operational mode, the transmitter signal is generated
by the internal battery. Due to the high-frequency signal generated by the transmitter, only one single
conductor can be located and traced. The second conductor is the earth. This arrangement causes a high
frequency current to flow through the conductor and to be transmitted to earth, similar to a radio and
receiver.
5.1.2 Double pole “live” method:
Connect the transmitter to the line and neutral conductors using both leads, ensuring correct polarity. The
transmitter power is drawn from the connected voltage supply. Using this method, the modulated current
flows through the phase into the transformer and back through neutral.
5.1.3 Double pole “dead” connection
A further option for testing “dead” or isolated systems is to terminate the transmitter to two line or neutral
cables and connect these together at the far end to make a complete circuit. In this mode, the transmitted
signal is generated by the internal battery. Then, the transmitter is supplied by the built-in battery.
NOTE : The Cable Locator can only detect or locate cables, which are connected correctly.
5.2 Single pole method (In open circuits)
5.2.1 Cable interruptions in walls and floors.
Finding and tracing cables, sockets, junction box, switches, pipes etc.
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General