Common cable failures
Wire surface mark - according to the national standard, the wire surface should be the manufacturer name, product model and rated voltage continuous mark. This is conducive to the use of the wire in the process of problems can be found in a timely manufacturing plant, consumers must pay attention to this when purchasing power lines. Meanwhile, consumers should pay attention to whether the manufacturer name, product model, rated voltage and the printed mark on the wire surface are consistent with the manufacturer's name, product model and rated voltage indicated on the qualified certificate, so as to prevent fake products.
Wire appearance -- consumers should pay attention to the appearance of the wire when purchasing the wire. The appearance of the wire should be smooth and smooth. From the cross-section of the wire, the thickness of insulation or sheath on the whole circumference of the wire should be even, not eccentric, insulation or sheath should be a certain thickness.
Conductor line diameter -- when purchasing electric wires, consumers should pay attention to whether the conductor line diameter is consistent with the section clearly shown in the certificate of qualification. It is recommended that 1.5mm and above specification should be adopted for domestic lighting lines. High power household appliances, such as air conditioners and microwave ovens, should use 2.5mm square wires or above.
Standard use -- the wiring should be standardized, and the fixed line should use BV single core wire to enter the pipe. Do not connect in the middle of a route; Do not touch the wire when the wire is connected to the electrical box. In addition, the household appliances with large electricity consumption, such as air conditioning, should be supplied by a single wire. Weak electricity, strong electricity with the wire had better maintain a certain distance.
The common faults of cables include mechanical damage, insulation damage, dampness of insulation, aging and deterioration of insulation, overvoltage, overheating of cables, etc. When circuit fault occur, will be cut off the power supply of the cable failure, to find fault point, the fault inspection and analysis, and then repair and test of the mutilation of mutilation, after being fault elimination, can restore power.
Safety requirements for buried cables
1. When the cable wire crosses each other, the high voltage cable should be below the low voltage cable. The minimum allowable distance is 0.15m if one of the cables passes through the pipe protection or is separated by a partition within 1m before and after the intersection.
2. When the cable and thermal pipe are close to or cross, the minimum distance of parallel and cross is 0.5m and 0.15m respectively if there is heat insulation measures.
3. When the cable crosses the railway or road, it shall be protected by pipe, and the protective pipe shall extend 2m beyond the track or road surface.
4. The distance between the cable and the building foundation shall ensure that the cable is buried outside the building's free water; When the cable is introduced into the building, it should be protected by pipe, and the protective pipe should be beyond the building's water distribution.
5. The distance between the cable directly buried in the ground and the grounding of the general grounding device shall be 0.15~0.5m; The buried depth of cables buried directly in the ground should generally not be less than 0.7m and should be buried under the permafrost.