The main function of cable identification instrument is to identify a cable from a bundle of cables. The structure is relatively simple and consists of three parts: signal generator, receiving clamp and signal detector.device. It is a common equipment in cable erection, migration, maintenance and fault treatment. The search method of cable identification instrument can be divided into live cable identification instrument and non-live cable identification instrument according to the use conditions.

Non-live cable detector search mode

The search method of non-live cable identification instrument is basically connected with live cable identification. The generator feeds periodic unipolar voltage pulses into the cable to be identified. This cable need to earth at the far end, in order to make sure there is enough electric current flows through the cable, in the direction of the pulse current in the cable can be as a clear identification standard, only from the outflow to the current through a cable, all other adjacent cables are the return current flows, the reverse polarity, but they are detected by receiver through the cable current direction and the size of it. The sensor clamps the cable under test. The magnetic field generated by the current flowing through the cable induces a voltage in the sensor coil. The polarity of the voltage is determined by the current direction and the direction of the sensor coil, thus achieving the recognition of the cable.

Live cable detector search mode

We must not interfere with the normal operation of the line when it is live. The sensing method is used to identify the cable with point. High frequency signals are transmitted through calipers. After receiving the signal characteristics, the receiver is filtered through software and hardware, and then phase recognition is performed. When the receiving calipers clamp the cable in the direction of the current, the identified cable ammeter is to the right, accompanied by an acousto-optic indication.

The current direction of other cables is opposite to that of the identified cables. The ammeter pointer is to the left, and there is no acousto-optic indication. This reflects the uniqueness of the identified target cable, and it is easy to distinguish the identified cable from multiple cables. Since the signal current strength on the identified cable is the same across the whole line, and the receiving calipers receive the same electromagnetic signal strength along the cable, in principle, the identified cable is not limited by the length of the identified cable.