(1) Current method
If a ground fault occurs in a tunnel cable, we can use the fact that the current direction before and after the fault point is opposite to find the fault point. The method is to apply a pulsating high-voltage signal to the faulty cable to cause discharge at the fault point. At this time, currents of opposite polarity will be generated before and after the fault point, but the current at the fault point is minimal.
Using this characteristic, we can use a receiving clamp to determine the direction of current before and after the fault point. Clamp the receiving clamp onto the cable, and the receiver box will indicate a direction. If you continue moving past the fault point, the current polarity will reverse, so by moving back and forth, you can accurately determine the grounding point.
(2) Withstand voltage function
Switch the function key to the withstand voltage function to output 0-10kV voltage for withstand voltage testing of the cable.
Functional features:
Adjustable voltage
Adjustable frequency
Overcurrent protection
One-key switching between fault location and withstand voltage
No blind spots in test range
Adjustable receiver sensitivity.
Signal frequency adjustment
Zero position protection
Technical specifications:
1. Input voltage: 220V (1±10%), 50Hz (1±5%)
2. Output voltage: 0～10kV (square wave) adjustable
3. Output current: max 200mA
4. Output capacity: 2kVA
5. Frequency adjustment: Min: 0.4Hz, Max: 1Hz (range adjustable)
Precautions
1. During testing, it is forbidden to touch the high-voltage connecting wire and the cable under test to avoid electric shock;
2. Do not turn on the power when connecting cables; turn off the power after the test;
3. When the current exceeds 200mA, the instrument will stop for protection;
4. The instrument cannot be started when the voltage adjustment is not at zero position;
5. If the receiver cannot be zeroed, please open the back cover of the receiver and check whether the 9V battery has power;
Packing list
Outer sheath fault tester main unit 1 unit
High-voltage output wire (50kV*5m) 1 piece
Power cord 1 piece
Ground wire 1 piece
Fuse Φ5×20 8A 2 pieces
Manual 1 copy
A-frame probe 1 set
A-frame connecting wire 1 piece
Current receiving clamp 1 piece
Receiver 1 unit
Note: The above information and technical parameters are compiled and released by Yangzhou DARUI Electric Co., Ltd.
