NOYAFA Electronic specializing in testing instruments and cable testers for 16 years
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NOYAFA Electronic specializing in testing instruments and cable testers for 16 years
Author: Noyafa–CCTV Tester
How does the cable identifier quickly distinguish the portable live cable identifier? How does the portable live cable identifier look for a specific cable in a bundle of cables? How to accurately identify the cable? Many power maintenance companies use cables commonly used in power cable erection, migration, maintenance and troubleshooting How does the identifier quickly distinguish the portable live cable identifier? How does the portable live cable identifier look for a specific cable in a bundle of cables? How to accurately identify the cable? Many power maintenance companies often use live cables in the erection, migration, maintenance and troubleshooting of power cables. Cable identification instrument, but in the face of complex cables and environmental differences, it has become very difficult to identify running cables. So what is the difference between a live cable identification instrument and an uncharged cable identification instrument? How to distinguish it quickly? 1. Working principle of the cable identification instrument: The main working principle of the live cable identification instrument is to transmit a phase code with an average value of 0 on the transmitting caliper Signal, the single-chip microcomputer in the receiving caliper filters the received signal by hardware and software, and then performs phase identification. When the receiving caliper clamps the cable according to the current direction, the ammeter of the identified cable is deviated to the right, accompanied by sound and light indication. . The current direction of other cables is opposite to the current direction of the identified cable, and the pointer of the ammeter is shifted to the left.
The working principle of the uncharged cable identification instrument is mainly to add a special signal to the identified cable, and the signal needs to be received by a special receiver. Periodic unipolar voltage pulses are fed into the cable to be identified, the direction of the pulse current fed into the cable can be used as an obvious identification criterion, and the outgoing current only passes through this cable. 2. Basic parameters of the cable identification instrument Insert the red and black wiring plugs of the transmitting caliper A into the two red and black binding posts corresponding to the transmitting source, and clamp the transmitting caliper A on the identified cable.
The arrow on launch caliper A points to the cable terminal. On the identified cable two meters away from the transmitting caliper, clamp the receiving caliper B on the cable, and the arrow on the caliper must point to the cable terminal. Then check the current direction and test connection direction.
At the identification point, use the receiving caliper B to identify each cable. When identifying, make sure that the arrow on the receiving caliper always points to the terminal direction of the cable, and test each cable one by one. On the identified cable, the pointer of the ammeter head of the receiver must be deflected to the right, and the sound and light alarm will prompt. , at this time, the magnetic field cannot be detected, and it is thought that it is a dead cable, which is very prone to misjudgment.
②If the cable is not running, but if this cable is in parallel with other running cables, an induced current will be generated, and the induced current will also generate a magnetic field. misjudgment. ③If there are multiple cables in the cable trench, these multiple cables will generate a magnetic field. At this time, there will be a magnetic field generated by a 50HZ current in the entire area. At this time, there will be a magnetic field in the entire area, making the judgment impossible. Misjudgment is easy to occur.
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