Cable Identifier
Working Principle
In order to reliably and accurately identify cables, it is necessary to apply a special signal to the cable to be identified. This signal must be received by a dedicated receiver, and using this characteristic, the target cable can be identified.
Cable IdentifierDLSB Cable Fault Locator works according to the following principle:
The generator feeds periodic unipolar voltage pulses into the cable to be identified. This cable needs to be grounded at the far end to ensure that a sufficiently large current flows through the cable. The system is designed so that the return current does not return through the same cable. If this can be achieved, the direction of the pulse current fed into the cable can serve as a clear identification criterion. The outgoing current passes only through this one cable, while all other adjacent cables carry return currents, but with opposite polarity. In addition to the practical difference in current direction, the current amplitude is also an identification feature. The outgoing current passes through only one cable, while the return current may pass through several cables, which means that the outgoing current is larger than the return current flowing through other cables.
The task of the receiver is to detect the direction and magnitude of the current flowing through the cable. To achieve this, a current clamp is used as a sensor, which is equipped with an amplifier and connected in series in the circuit. The clamp clamps onto the cable under test. The magnetic field generated by the current flowing through the cable induces a voltage in the coil of the clamp. The polarity of this voltage is determined by the direction of the current and the orientation of the clamp coil. In order to obtain a clear voltage polarity indicating the current direction, all cables in a bundle are tested with the same correct winding direction. This is the reason why an arrow is marked on the clamp. The direction of the arrow on the clamp should point towards the far end of the cable. The voltage induced in the clamp coil is displayed on the meter. If the clamp is connected in the manner described above, the direction of the pointer deflection can indicate the current direction. That is, only the cable with outgoing current will cause the pointer to deflect to the right, and this is the cable to be found. All other cables only carry return current, causing the pointer to deflect to the left, or if there is no pulsating current, the pointer does not deflect. The amplifier adjustment on the receiver can adjust the signal strength.
Note: The above information and technical parameters are compiled and released by Yangzhou Darui Electric Co., Ltd.
