Cable Maintenance Cycle and Preparations Before Laying

I. Cable Maintenance Cycle

       Major maintenance is performed once every three years, and minor maintenance is performed 1 to 2 times per year.

1. Major Cable Maintenance

      Clean the surfaces of cable terminals and lead wires.

　  Use a 0.05 mm feeler gauge to check the contact surface of the cable lug; it should not be able to be inserted. If overheating is observed, re-polish and treat it, and if necessary, remake the terminal.

      Check that the grounding wire and fixing clamps are securely fastened.

Darui Equipment Co., Ltd.Safety tools testing equipment is produced to meet the development needs of China's power industry, respond to the spirit of the new version of the "Safety Regulations" of the State Grid Corporation, and support the standardized construction of substations and power supply stations.      For cables that fail the test, the cause should be identified and addressed.

2. Minor Cable Maintenance

     Clean the surfaces of cable terminals and lead wires.

     Measure the cable insulation; if it is unqualified, identify the cause and address it.

3. Handling of Poor Cable Insulation.

     When the exterior of the cable terminal is damp, it can be dried using methods such as infrared lamps or hot air from a hair dryer.

     If the interior of the cable is damp, a section of the cable must be sawed off, and after the insulation passes the test, a new terminal should be made.

     When there is an obvious grounding or short circuit in the cable, the fault location can be found by external inspection or by applying a higher voltage to break down the fault, and then it can be handled.



II. Preparations for Cable Laying

Selection of Cable and Route:

1. For 6kV cables buried directly underground, armored cables with a protective layer should be selected; for cables of 1 kV and below, if there is no risk of mechanical damage or chemical corrosion, unarmored cables with a protective layer can be used.

2. For cables of 1kV and below laid in trenches or tunnels, unarmored cables should be used.

3. For cables laid in pipes, thickened bare lead-sheathed cables should be selected (bare armored cables can be used in short pipes crossing roads).

4. Cables laid indoors or in cable trenches must not have a jute protective layer.

5. Select cables with appropriate voltage and cross-section according to work requirements.

6. The cable route should be chosen to avoid various damages and be economically and technically advantageous.

Handling of Cables:

1. Try to use the original cable reel for rolling; if it has been dismantled, the cable should be securely tied to prevent loosening during rolling. The rolling direction should be consistent with the cable winding direction.