Method for repairing non-penetrating damage of outer sheath of high-voltage single-core cable

Abstract

The invention relates to a non-penetrating damage repairing method for an outer sheath of a high-voltage single-core cable. The non-penetrating damage repairing method comprises the following steps: cleaning and wiping the outer sheath of the cable; then, the outer sheath of the damaged part is stripped and treated; the insulating property of the outer sheath is recovered by using the insulating tape; meanwhile, the waterproof performance is recovered by wrapping a waterproof tape; the conductivity of the outermost layer is recovered by wrapping the semi-conductive belt; according to the non-penetrating damage repairing method for the outer sheath of the high-voltage single-core cable, the insulating performance of the outer sheath of the cable can be quickly and well recovered, and the potential engineering application value is achieved.

Description

Technical Field

[0001] The invention belongs to the technical field of cable operation, maintenance and repair, and in particular to a method for repairing non-penetrating damage to an outer sheath of a high-voltage single-core cable. Background Art

[0002] The outer sheath of the power cable is the outermost structural layer of the power cable, which is used to protect the inner structure of the power cable. For three-core cables, the main function of the outer sheath is mechanical protection and corrosion protection. For single-core high-voltage cables of 66kV and above, the outer sheath of the cable not only plays a role in mechanical protection and corrosion protection, but also plays the role of an insulating layer of the metal sheath. Therefore, the insulation performance of the outer sheath is very important. In addition to polyvinyl chloride outer sheath and polyethylene outer sheath, the types of outer sheaths of high-voltage cables also include metal-plastic composite jackets. In addition, the surface of the outer sheath of high-voltage single-core cables has a semi-conductive layer extruded or coated, which is significantly different from three-core power cables of 35kV and below. Whether it is a three-core cable or a single-core cable, maintaining the integrity of the outer sheath is a basic condition to ensure the long-term safe and reliable operation of the cable.

[0003] During construction and operation, the cable sheath may be damaged due to mechanical force, ants or small animals biting, etc. If the damage is relatively minor, it will lead to non-penetrating damage. Non-penetrating damage generally refers to the cable sheath hitting a sharp object during the construction process, causing the cable sheath to be scratched, or the cable sheath is corroded by organisms or burned at high temperature, causing the surface of the cable sheath to deteriorate. Summary of the invention

[0004] The purpose of the present invention is to overcome the deficiencies of the prior art and to propose a method for repairing non-penetrating damage to the outer sheath of a high-voltage single-core cable, which can quickly and well restore the insulation performance of the outer sheath of the cable and has potential engineering application value.

[0005] The present invention solves the technical problem by adopting the following technical solutions:

[0006] A method for repairing non-penetrating damage to an outer sheath of a high-voltage single-core cable comprises the following steps:

[0007] Step 1: Clean and wipe the outer sheath of the cable;

[0008] Step 2, stripping and treating the outer sheath of the damaged part;

[0009] Step 3: Use insulating tape to restore the insulation performance of the outer sheath;

[0010] Step 4: Wrap the waterproof tape to restore the waterproof performance;

[0011] Step 5, wrapping the semi-conductive tape to restore the outermost layer's conductive properties;

[0012] Step 6: Conduct insulation performance test to check the repair effect.

[0013] Moreover, the specific implementation method of step 2 is: use a glass sheet to scrape off the conductive layer within 50 mm around the damaged area and use a cleaning towel to remove surface impurities and dust particles. Note that no semi-conductive material can remain on the scraped surface, and use a multimeter to test the conductivity of the scraped surface. The test result should show an open circuit.

[0014] Moreover, the specific implementation method of step 3 is: fill the damaged part with the repair material of the same material as the cable outer sheath, heat the sheath insulation material with a hot air gun and smooth it with polytetrafluoroethylene tape; then wrap the insulation tape, overlap more than 60mm, and restore the insulation performance.

[0015] Moreover, the repair material is PE or PVC.

[0016] Moreover, the specific implementation method of step 4 is: wrapping the waterproof tape requires covering the insulating tape range of more than 60mm to ensure waterproof performance, and then wrapping the black PVC adhesive tape to enhance wear resistance and corrosion resistance.

[0017] Moreover, the specific implementation method of step 5 is: wrapping the semi-conductive tape to restore the semi-conductive performance, and the semi-conductive tape overlaps the outer conductive layer of the intact part of the cable on both sides by no less than 50mm to ensure the connectivity of the conductive layer.

[0018] Moreover, the specific implementation method in step 6 is: the insulation performance of the repaired outer sheath should be able to withstand a 10kV DC voltage for 1 minute without breakdown.

[0019] The advantages and positive effects of the present invention are:

[0020] The present invention cleans and wipes the outer sheath of the cable; then strips and treats the outer sheath at the damaged part; then uses an insulating tape to restore the insulation performance of the outer sheath; at the same time, wraps a waterproof tape to restore the waterproof performance; and wraps a semi-conductive tape to restore the outermost conductive performance; finally, an insulation performance test is performed to check the repair effect to complete the repair of non-penetrating damage to the outer sheath of the high-voltage single-core cable. The present invention can quickly and better restore the insulation performance of the outer sheath of the cable, and has potential engineering application value. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 Flowchart of the present invention

[0022] Figure 2 This is a schematic diagram of non-penetrating damage to the outer sheath of the present invention;

[0023] Figure 3 It is a schematic diagram of the structure after repair of the present invention. DETAILED DESCRIPTION

[0024] The present invention is further described in detail below with reference to the accompanying drawings.

[0025] A method for repairing non-penetrating damage to the outer sheath of a high-voltage single-core cable. Figure 2 In the case of non-penetrating injuries as shown, Figure 1 The modification method shown in the figure is used to repair the problem, which specifically includes the following steps:

[0026] Step 1: Clean and wipe the outer sheath of the cable.

[0027] Step 2: Remove and treat the outer sheath of the damaged area.

[0028] Use a glass sheet to scrape off the conductive layer within 50mm around the damaged area and use a cleaning towel to remove surface impurities, dust particles, etc. Be careful not to leave any semi-conductive material on the scraped surface. Use a multimeter to test the conductivity of the scraped surface. The test result should show an open circuit.

[0029] Step 3: Use insulating tape to restore the insulation performance of the outer sheath.

[0030] Fill the damaged area with repair material of the same material as the cable outer sheath (usually PE, PVC), use a hot air gun to heat the sheath insulation material and smooth it with polytetrafluoroethylene tape; then wrap the insulation tape, overlapping more than 60mm, to restore the insulation performance.

[0031] Step 4: Wrap the waterproof tape to restore the waterproof performance.

[0032] The wrapped waterproof tape is required to cover the insulating tape range of more than 60mm to ensure waterproof performance, and then wrapped with black PVC adhesive tape to enhance wear and corrosion resistance.

[0033] Step 5: Wrap the semi-conductive tape to restore the outermost conductive property.

[0034] Wrap the semi-conductive tape to restore the semi-conductive performance. Wrap the outermost layer with two layers of PVC protective tape to protect the semi-conductive tape. The semi-conductive tape and the outer conductive layer of the intact cable on both sides should overlap by at least 50mm to ensure the connectivity of the conductive layer.

[0035] Step 6: Conduct insulation performance test to check the repair effect.

[0036] The insulation performance of the repaired outer sheath should be able to withstand a 10kV DC voltage for 1 minute without breakdown.

[0037] like Figure 3 As shown, the outer sheath of the high-voltage single-core cable repaired by the present invention is Figure 3 It can be seen that the repair method of the present invention can better restore the insulation performance of the cable outer sheath and has potential engineering application value.

[0038] It should be emphasized that the embodiments described in the present invention are illustrative rather than restrictive. Therefore, the present invention includes but is not limited to the embodiments described in the specific implementation manner. Any other implementation manners derived by those skilled in the art based on the technical solution of the present invention also fall within the scope of protection of the present invention.

Claims

1. A method for repairing non-penetrating damage to the outer sheath of a high-voltage single-core cable, characterized in that: The following steps are involved: Step 1: Clean and wipe the outer sheath of the cable; Step 2, stripping and treating the outer sheath of the damaged part; Step 3: Use insulating tape to restore the insulation performance of the outer sheath; Step 4: Wrap the waterproof tape to restore the waterproof performance; Step 5, wrapping the semi-conductive tape to restore the outermost layer's conductive properties; Step 6: Conduct insulation performance test to check the repair effect.

2. A method for repairing non-penetrating damage to the outer sheath of a high-voltage single-core cable according to claim 1, characterized in that: The specific implementation method of step 2 is: use a glass sheet to scrape off the conductive layer within 50 mm around the damaged area and use a cleaning towel to remove surface impurities and dust particles. Note that the scraped surface cannot be stained with semi-conductive materials, and use a multimeter to test the conductivity of the scraped surface. The test result should show an open circuit.

3. A method for repairing non-penetrating damage to the outer sheath of a high-voltage single-core cable according to claim 1, characterized in that: The specific implementation method of step 3 is: fill the damaged part with the repair material of the same material as the cable outer sheath, heat the sheath insulation material with a hot air gun and smooth it with polytetrafluoroethylene tape; then wrap the insulation tape with an overlap of more than 60mm to restore the insulation performance.

4. A method for repairing non-penetrating damage to the outer sheath of a high-voltage single-core cable according to claim 3, characterized in that: The repair material is PE or PVC.

5. A method for repairing non-penetrating damage to the outer sheath of a high-voltage single-core cable according to claim 1, characterized in that: The specific implementation method of step 4 is: wrapping the waterproof tape to cover the insulating tape range of more than 60mm to ensure waterproof performance, and then wrapping the black PVC adhesive tape to enhance the wear and corrosion resistance.

6. A method for repairing non-penetrating damage to the outer sheath of a high-voltage single-core cable according to claim 1, characterized in that: The specific implementation method of step 5 is: wrapping the semi-conductive tape to restore the semi-conductive performance, and the semi-conductive tape overlaps the outer conductive layer of the intact part of the cable on both sides by no less than 50mm to ensure the connectivity of the conductive layer.

7. A method for repairing non-penetrating damage to the outer sheath of a high-voltage single-core cable according to claim 1, characterized in that: The specific implementation method of step 6 is: the insulation performance of the repaired outer sheath should be able to withstand a 10kV DC voltage for 1 minute without breakdown.

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