What should I pay attention to when lying directly buried? Under what circumstances?
When laying cables directly underground, it is necessary to consider whether the cables are susceptible to damage caused by external impacts.
1 If it will not be subjected to large impacts, direct laying is possible.
2 If it may be subject to some relatively large impact, but the strength can be controlled within a certain range, you can consider armored direct burial.
3 If the external force is greater, it is necessary to use a protective casing, which can be set up locally, such as through the highway.
Advantages: easy to lay, saving materials and labor.
Disadvantages: maintenance is inconvenient, if you want to maintain, you need to dig up the overburden, only recommended to be used in a place that does not consider maintenance, or can accept this kind of maintenance. Direct burial is generally required to pad yellow sand.
How do I find the point of failure for a direct buried cable that is grounded?
A: Use a roving cable tester.
Cable laying in the plant, using armored cable direct burial, crossing the road and into the workshop power distribution room at the need to add cable wells? Municipal 10KV cable into the plant at the need to add cable wells?
A: Cable in 6 and below can not set up cable wells, cable more wells, easy to replace, add cable.
Municipal 10KV cable into the plant does not need to set up cable wells, from the terminal pole lead down to the high-voltage distribution cabinet can be buried.
Cable laying through the pipe, compared with direct burial, is more convenient for late maintenance and increases the line. Cable through the pipe laying, you can consider some spare tubes, for future line maintenance and capacity increase and other preparations.
1 Laying through the pipe, in the line turning angle is a large, or straight section of the longer distance need to consider setting up cable wells.
2 Cable handwells can be used when the number of cables is small and the wire diameter is small.
3 More cables, wire diameter is larger, need to consider the installation of cable manhole.
Cable manholes can be done according to the atlas approach. In addition to the atlas practice, many small crossing wells can also be directly brick or concrete pouring, at this time to consider the bottom of the seepage hole.
4 Through the pipe material is now more cast iron pipe, steel pipe, polyethylene pipe, nylon pipe, carbon pipe, etc., can be selected according to need. Single-core cable through the metal pipe should pay attention to the effect of eddy current.
Pipe laying is mainly used in areas where there are more lines and routing is more centralized, which makes it relatively easier to put the pipe and saves more materials.
Outdoor pipe laying cable, is a row of pipes, a cable, or more cables can be a row of pipes?
A: It is appropriate to wear only 1 cable per pipe. Except for power plants, substations, and other important places, for all circuits of one motor or all circuits of low-voltage motors of the same equipment, no more than 3 power cables or control cables can be threaded in each pipe.
There is a factory outside the line, and there are more than a dozen low-voltage power cables, in addition to weak power cables, strong power cables of more than 8 can not be buried directly, so I used the row of pipe laying. But now there is a problem: the weak power is also laid through the pipe, then the strong power pipe and weak power pipe can be arranged all the time.
A: Try not to line up together, do small municipalities try to set the strong and weak power pipes on both sides of the road? If there are occasional crossings, etc., it is recommended that the implementation of spacing requirements by the norms. You can refer to the underground communication cable laying 05X101-2 and so on.
Cable trench laying should pay attention to, different voltage levels of cables should be divided into different bracket settings, and the cable trench itself should pay attention to drainage measures. And consider measures to prevent the entry of small animals such as rats.
How many cables need to be laid in the cable trench?
A: The number of cables can be connected to the actual project reference, but not so fixed. As for cable trench and cable tunnel, it is not the difference between the number of roots, but the difference between maintenance and importance.
Mainly depends on the engineering conditions, environmental characteristics, and the number of cable types and other factors, as well as to meet the requirements of reliable operation, easy maintenance, and technically and economically rational choice, not sure whether there is a mandatory indicator requirements.
Can bus ducts be laid along the cable trench?
A: There is no requirement, the depth of the cable trench is based on the number of your cable and the number of cable types to decide. For example, if there are control cables, low-voltage power cables, and high-voltage power cables, it is usually set up in three layers, and generally, the spacing between each layer is 250~300, to determine the height.
A high-rise hospital project, to save money, the choice of oil-immersed transformers installed outdoors, 15 meters from the building, low-voltage distribution room located in the hospital underground, to save investment, I would like to use the busbar (current-carrying 3000A) along the cable trench laid to the building house underground distribution room, I wonder if it is feasible?
A: It should be possible to use a dense busbar that meets the requirements of the corresponding IP rating, for example, Siemens or ZMS cables have busbars that can be laid underwater.
However, the use of a dense busbar cost will be higher, need to consider the choice of dry-type transformer and the use of a busbar which is better.
I recommend the use of dry-type transformers, placed indoors. The maintenance workload will be smaller, and the failure rate will be lower.
How many cables can be laid in the cable trench without support?
A: Generally it is necessary to have a bracket. If there is no bracket, cable maintenance in the cable trench will be more troublesome.
If the project is not big, and the number of cables is not much, there is no harm in not setting, but the heat dissipation conditions will be worse, and if there is water in the trench, it will have an impact on the cables.
Do cables have to be armored when they are laid in cable trenches?
Answer: There is no mandatory requirement to use armor for direct buried cables, and even less for cable trenches.
Different environmental requirements are not the same, if the region is rampant with rat activity, it is recommended that armored, generally no mandatory requirements.
In winter, as the temperature plummets, cable laying difficulty increases, and laying construction easily damages the insulation.
So in this case, the winter cable laying should be how to start, winter cable laying should pay attention to what matters.
First, before the cable laying, must be fully prepared.
Should organize the construction personnel concerned to learn construction measures and precautions, familiar with the cable laying construction drawings and technical documents.
And develop a strict winter construction management system, development of good construction measures and precautions, construction of smooth roads, snow, and ice removal promptly, and the work surface for the freezing phenomenon.
Second, in the cable laying process, one must pay attention everywhere, and always be ready.
When the weight of the ice exceeds the acceptance capacity of the wire and cable, due to the wire and cable overhead outdoors.
It will be easy to lead to the cable being pulled to the transmission tower or pulled to the pole as well as the phenomenon of the cable itself collapsing.
Then, to prevent this from happening, in the choice of information pay attention to the selection of cables that can withstand the cold.
Third, low-temperature weather cable laying work, more attention should be paid.
Suppose the temperature is below -5 ℃ for open-air work. In that case, the construction site should be set up near the heating lounge, heating facilities should be in line with the fire regulations, and construction heating facilities must be hung with obvious signs to prevent personnel burns.
Fourth, if the cable storage site's ambient temperature is lower than the use of cable conditions, do not put the cable, such as cable in a warm place to store it 24 hours before laying.
Fifth, before the cable pulling and laying, should carefully check the cable code, specifications, length, start and end of the name and location of the equipment and cable list and drawings are consistent, and check whether the cable is damaged.
Sixth, after each cable pulling and laying, the cable should be straightened and leveled, calibrated length, and the cable rolled up and hung near the equipment.
The cable should not be thrown anywhere, arbitrary trampling, so as not to damage the cable.
Seven, all the cables after pulling and laying, should comprehensively check the cable type, specifications, the length of the equipment into the total number of lengths, to prevent laying the wrong or missing, strictly do a good job in the winter, and make a good record.
The above is about the daily and winter seasons when laying cable precautions. If you have any want to know, you can always consult us.