As a part of power lines, power cables are widely used due to their low failure rate, high safety and reliability, and flexible sockets. However, once a failure occurs, maintenance will be more difficult and dangerous, so attention should be paid to maintenance and testing.
1. Preparation before work
The first type is used for outage work of the power cord, and the second type is used for work that does not require a power outage. Before working, please check the related roadmap, layout and hidden engineering drawings. You need to check whether the names of the cables and nameplates are consistent with the work order. Only after taking correct and reliable measures can you start working.
2. Matters needing attention at work
The cable to be repaired must be confirmed when working. There are two types of cables that need to be repaired:
(1) Cables with faults on the surface of the cable head and protruding fault points. This faulty cable has prominent signs of failure and is easy to identify.
(2) For cables with no fault points on the cable surface, for such faulty cables, in addition to checking the data and verifying the cable name, the cable identifier needs to be marked to distinguish it from other live cables in operation, especially in the same When there are many cables in the part; it is particularly important to distinguish the cables that need overhaul from other live cables. At the same time, this can also prevent misidentification of cables due to incorrectpower cable labels, resulting in accidental disconnection of live cables.
When sawing the cable, it is necessary to take reliable protection measures; before sawing the cable, it is necessary to confirm whether the cable needs to be cut and the cable has no electricity; then, before working, insert the subway with a wooden handle (epoxy handle) In the cable core; the person holding the wooden handle should wear insulating gloves and stand on the insulating mat, and pay attention to ensure that the iron brazing is well grounded; if you need to move the cable during work, you should be careful and avoid excessive operation to avoid damage to the running The cable head needs to be installed according to the process requirements to ensure the quality and there is no hidden danger of accident; after repairing the cable, please carefully check the two ends of the cable, first remove the original color mark, and then paste the correct color mark to prevent The old and new colors are mixed.
3. Matters needing attention in high voltage test
Aerial Bundled Cable (ABC) BS 7870 Standard high voltage testing should strictly abide by the "Safety Work Regulations for the Electrical Industry", and the requirements should not be reduced at all even under harsh on-site working conditions; the division of labor should be clearly defined, and preventive measures should be arranged in detail, and closed fences or fences should be installed at the test site; It is marked with the words "Stop, high voltage danger!"; it should be hung outward and protective measures should be sent, especially when the other end of the cable needs to be protected and the communication must be kept open to prevent emergencies.
The test equipment and wiring should meet the requirements, and the operation should be standardized; during the test, attention should be drawn, and the operator should stand on the insulating pad; when the circuit is changed or the test is over, the test power supply should be disconnected, discharged, and The high-voltage part of the high-voltage equipment is grounded; in the high-voltage test, before touching the cable, the cable should be discharged to the ground several times and short-circuited to the ground at the end of each test or at the end of the test.