Insulating Resistance of Cables

1. Cable Testing Requirements and Preparations Before Testing

1）Prior to partial discharge testing, disconnect and ground the cable, leaving both ends suspended, and set up safety fencing.

2) Efforts are being made to optimize cable joint areasPTDisconnection of lightning arresters and other equipment.

3) Ensure cable ends are clean and that the insulating distance between the cable ends and the surrounding grounding areas is sufficient.

4) Gather cable parameters such as length, model, type, and commissioning date.

5) Cable Length L: Measurement method on one side of the cable: 50m ≤ L ≤ 3km;

Measurement method at both ends of the cable:L＞3km。

2. Insulation Resistance Testing

10kV Cable Main Insulation Resistance Test: Utilizing a 2500V insulation tester for testing, the insulation resistance should show no significant change before and after the test; for the 10kV cable main insulation resistance test, the insulation resistance must be greater than 50MΩ to proceed to the next phase of testing.

3. Test the intermediate joint position of the cable and the cable length

AdoptedSEBAKMT Easyflex ComMultifunctional Pulse Reflectometer (as shown)2) Conducted tests on the full length of the cable and the positions of intermediate joints to measure cable length and joint locations, as well as to pre-position for cable short-circuit and open-circuit faults.

Test Requirements:

The entire cable length must be accurate for calibration purposes.

Intermediate joint measurements should be as accurate and detailed as possible, which is beneficial for final determination of partial discharge locations.

3) Measurement Range:50m～15000mThe measurement range needs to be adjusted according to the cable length.