5
The difference with the live cable identification is: do not use the transmitter calipers, untie the start and
end of the cable to be identified, untie the armor wires on both sides, use the dedicated direct connection
output wire, the red wire is connected to the cable core wire, and the black wire is connected The earth,
the cable core wire terminal is connected to the earth. Refer to 1 for other operations.
This method is suitable for situations where the start and end of the cable are known, and the middle
position of the cable is found with an instrument.
This method is suitable for situations where the beginning and end of a cable are known and an
instrument is used to find the middle position of the cable.
V.Working principle of live cable identification
Apply the signal to the cable to be recognized through the output coupling clamp. According to the
principle of electromagnetic induction, if the copper shielding layer of the cable is intact and the two ends
are grounded reliably, the copper shielding layer of the cable will inevitably induce an induction signal
consistent with the transmitted signal law , At the site to be identified, use the receiving test clamp of the
handheld receiving box to test all the cables on the spot. According to the displayed waveform, the cable
with the same direction and similar amplitude is the cable of the added signal.
VI.Precautions
1. If there is a ground or branch in the middle of a live cable, only the part before the ground or branch of
the cable can be identified.
After adding a coupled signal to the cable, no obvious effective signal can be measured with the flexible
coil and the receiving box. You can leave the transmitter clamp about 3 meters to avoid signal
interference. If there is still no effective signal display, it means that the copper shielding layer of the
cable has a broken point or The grounding of both ends of the cable is not reliable.
At this time, generally check the grounding of the cable to be identified. If you find that the shielding layer
has a disconnection point, you can use a grounding clamp to ground the disconnection point before and
after the disconnection point, and then identify it in sections.
This phenomenon does not exist when the uncharged cable is identified according to the above four and
2.
2. If the receiver is about 3m away from the host, there is a signal for verification and identification, but
there is no signal at the site to be identified, or the signal is too small to be identified, it means that the
cable to be identified must have multiple metal outer sheath grounding points In this case, the power
