Direct Burial Cables: How to Choose and Install for Reliable Underground Connections

Article summary:

Directly buried cables are widely used in underground connections, and their selection and installation are crucial to ensure the reliability of the connection. This article will introduce the types of directly buried cables, selection points, installation steps and precautions in detail, so as to help readers better select and install directly buried cables and achieve reliable underground connections.

Directly buried cable, selection, installation

Table of Contents:

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Overview of Direct Buried Cable

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Types of directly buried cables

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How to Choose a Directly Buried Cable

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Installation steps for directly buried cables

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Precautions for installing directly buried cables

Overview of Direct Buried Cable

Directly buried cable is a kind of cable laying method directly buried in the ground. It is widely used in underground connection in power tranSMission, communication and other fields because of its advantages such as simple installation and no occupation of ground space. This kind of cable needs to have good insulation properties and mechanical protection properties to cope with complex underground environmental conditions.

Types of directly buried cables

1. Power direct buried cable: Mainly used for the transmission of power, according to the different voltage levels, it can be divided into low-voltage, medium-voltage and high-voltage power direct buried cables. Cables of different voltage levels vary in insulation materials and structural design to meet corresponding safety and transmission requirements.

2. Communication direct buried cable: used to transmit various communication signals, such as telephone calls, network data, etc. Common are fiber optic direct buried cables and copper core communication cables. fiber optic cables have the advantages of fast transmission speed and large capacity, while copper core cables are still used in some short-distance and relatively low transmission requirements.

How to Choose a Directly Buried Cable

1. Determine the requirements for use: First, it is necessary to clarify the purpose of the cable, whether it is used for power transmission or communication, as well as the type of power or signal required for transmission, transmission distance, etc. According to these requirements, the appropriate cable type is initially screened.

2. Consider environmental factors: The underground environment may be humid, acid-alkali corrosion, mechanical stress, etc. To choose cables with corresponding protective properties, such as in humid environments, cables with good waterproof performance should be selected; in chemically corrosive soils, corrosion-resistant cable sheathing materials should be selected.

3. Pay attention to cable specifications: according to the current or signal transmission requirements, choose the appropriate cable specifications, including the cross-sectional area of the conductor, the thickness of the insulation layer, etc. The cross-sectional area of the conductor should meet the requirements of the load current to avoid cable overheating and cause safety problems.

Installation steps for directly buried cables

1. Cable path planning: Before installation, carefully plan the cable laying path. Try to choose the shortest and straightest path to avoid excessive cable bending. At the same time, avoid other underground facilities, such as pipelines, building foundations, etc., to prevent mutual interference.

2. Trenching: According to the number and specifications of the cable, dig the appropriate depth and width of the cable trench. Generally speaking, the depth of the cable trench should ensure that the cable is buried below the permafrost layer to prevent damage to the cable due to soil freezing and thawing.

3. Cable laying: Lay the cable along the cable trench, paying attention to keep the cable straight to avoid twisting, knotting, etc. For multiple cable laying, maintain a certain spacing for heat dissipation and maintenance.

4. Backfill: After the cable is laid, cover the cable with a layer of fine sand or soft soil, usually 10-15 cm thick, and then backfill the original soil and layer it.

5. Do a good job of marking: Set up obvious signs on the ground of the cable path, such as cable piles, warning tapes, etc., for future maintenance and repair.

Precautions for installing directly buried cables

1. Cable protection: During the laying process, pay attention to protecting the insulation layer of the cable to avoid mechanical damage. Auxiliary facilities such as cable protection tubes can be used, especially when cables cross roads, buildings, etc.

2. Waterproof treatment: Although directly buried cables have certain waterproof performance, they still need to be waterproof in cable joints and other parts. Special waterproof sealing materials can be used to prevent moisture intrusion from affecting cable performance.

3. Grounding requirements: For power direct buried cables, ensure good grounding to ensure power safety. Grounding resistance should comply with relevant standards.

Related questions and answers:

What environments are directly buried cables suitable for use?

Answer: Directly buried cables are suitable for environments that do not require frequent maintenance and have limited ground space, such as urban streets, parks, factories, and other underground connection scenarios.

How to determine whether the specifications of a directly buried cable are appropriate?

Answer: According to the required transmission current, voltage level, and transmission distance, etc., refer to the cable specification table to determine whether the conductor cross-sectional area and other specifications are appropriate.

How long is the service life of a directly buried cable?

Answer: Under normal environmental and maintenance conditions, the service life of directly buried cables is usually 20 to 30 years, but it is also affected by environmental factors and cable quality.

How to avoid conflicts with other underground facilities when installing directly buried cables?

Answer: Before installation, it is necessary to understand the distribution of underground facilities in detail, and plan the cable path rationally by consulting data and on-site exploration.

How to waterproof the joints of directly buried cables?

Answer: Special waterproof sealing materials such as waterproof sealing tape and waterproof heat shrinkable tube can be used to wrap and seal the cable joint.