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XI.Cable low resistance and broken line fault points
This chapter is an auxiliary chapter, please choose to read as necessary.
When the cable fault resistance is low, if the legal point of high-voltage impact discharge
is adopted, the discharge sound at the fault point is weak, especially if there is no
discharge sound in the fault of gold property dead earth, and the accurate fixed point of
acoustic measurement method fails, audio induction method should be changed. The
audio frequency method is generally only applicable to low resistance fault with
resistance less than 10 ohms. A satisfactory result can be obtained by using the audio
induction method to the two-phase or three-phase short-circuit (or combined ground) fault
point, and the error of the general point is 1-2 meters.
Audio legal points can also be used for broken wires.
1. Phase-to-phase short circuit fault point
1) Signal transmission method
As shown in the figure, the two ends of the metal sheath of the cable should be earthed
first, and the zero line and ground line grounding of the low-voltage cable should also be
earthed. The transmitter should be directly connected with the output to connect two fault
core wires. The receiver must be moved parallel to the cable and detected using the peak
method.
Summary of Contents for HZ-5000
Page 1: ...HZ 5000 Underground Cable Detector User Manual Huazheng Electric Manufacturing Baoding Co Ltd...
Page 35: ...33 Figure a Illustration of Deeper Pipes Figure b Illustration of T Branch Pipe...
Page 37: ...35 Figure e Illustration of Detection under Steel Mesh Net Illustration of Depth Measurement...
