Project Description
Maintenance of cable fault dectaor circuit measuring point in Xi’an substation
Project Name: Maintenance of 10kV cable fault measuring point in Xi’an substation
Cable overview:
| Cable name | Chanba Peninsula community in the eastern suburb of Xi'an | Cable medium | Crosslinked polyethylene |
|---|---|---|---|
| Voltage level | 10KV | Cable length | 1150m |
| Fault nature | High resistance fault | Test equipment | LTDL-VI |
| Test method | Low voltage pulse, high voltage impulse flashover | Laying mode | Directly buried, through pipe and Bridge |
Fault nature judgment:
how to find fault in underground cable
The cable is 10kV power cable of Chanba Peninsula community in the eastern suburb of Xi’an. Xi’an substation immediately went to repair after receiving the notice. Our worker ude cable fault finder to find cable fault in underground.
The insulation resistance tester is used to measure the relative armor of cable a is infinite, the relative armor of cable B is infinite, the relative armor of cable C is almost 0 megohm, and the relative armor of cable C is 0.25 megohm measured by multimeter. Therefore, it is judged that the cable fault is a high resistance fault of cable C.
Test process:
1. The total length of the cable is about 1150M measured by low voltage pulse method, as shown in the figure below.
2. Test the c-phase fault waveform by impulse flashover method, and judge the fault point at 190m, as shown in the figure below.
3. Because the cable laying time is long, it helps users to find the path again.
4. Add about 18kV impulse high voltage to C, and then go to about 190m to fix the point, and finally determine the fault point, as shown in the figure below.
5. After excavation, the final fault point is the joint fault, which is completely consistent with the fixed point, as shown in the figure below.
Test summary:
The cable laying time is long, the path is complex, and the cable is often damaged by external force due to construction, which is a typical construction failure. Therefore, it is necessary to strengthen the detection of buried cables before construction to ensure the reservation of construction excavation. Reduce the occurrence of power cable failure and ensure reliable power transmission.
