In depth analysis of waterproof cables

In depth analysis of waterproof cables

• 2024-12-23 16:07:41
• by Admin

In-depth Analysis of FS-VV/FS-YJV Waterproof Cables

I. Definition and Essence of Waterproof Cables

Waterproof cables, as a crucial category in the cable field, are mainly designed to prevent water from entering the internal structure of the cable. This excellent protective performance is achieved by ingeniously adopting structural forms and high-quality waterproof materials with special waterproof functions in the design and material selection of the cable sheath, ensuring that the cable can still transmit electricity stably and safely even in harsh wet and water-rich environments. 

II. Detailed Introduction to FS-VV/FS-YJV Waterproof Cables

Diverse Core Numbers:

This type of waterproof cable offers a wide variety of core number options, including single-core, 2-core, 3-core, 4-core, 5-core,etc., which can fully meet the wiring requirements of electrical systems with different levels of complexity.

Whether it's a simple lighting circuit or a complex industrial control system, it can be precisely matched.

Wide Range of Specifications:

Its specification range extends from 1.5 square millimeters to 240 square millimeters.

Such a wide specification range enables it to handle the power transmission tasks of various loads, from small-power household equipment to large-scale industrial machinery, providing just the right current-carrying capacity for equipment with different power requirements.

Distinctive Appearance Characteristics:

The color is uniformly classic black.

This calm color not only meets the aesthetic needs of most engineering application scenarios but also has practical features such as being dirt-resistant and weather-resistant to some extent, ensuring that the cable maintains a clean and recognizable appearance during long-term use.

Excellent Material Quality: 

It uses national standard oxygen-free copper as the conductor material, ensuring the high efficiency and stability of current transmission. The extremely low resistance effectively reduces the power loss during the transmission process. The sheath is made of polyvinyl chloride or cross-linked polyethylene. These two materials, with their excellent insulation performance, mechanical strength, and waterproof characteristics, provide a comprehensive protective barrier for the copper core inside the cable, protecting it from the erosion of the external environment.

III. Wide Range of Application Scenarios

Thanks to its outstanding comprehensive performance, the FS-VV/FS-YJV waterproof cable has found its place in numerous fields.

It is suitable for both indoor electrical wiring environments that are relatively dry but have high safety requirements, such as the lighting and power systems of large shopping malls and office buildings.

It can also work stably in relatively closed and humid spaces like cable trenches, pipes, and tunnels, safeguarding power transmission in urban infrastructure construction.

Even when buried in loose soil, although it cannot withstand excessive external force impacts, as the main artery of circuit transmission, it can reliably distribute power for power lines under the rated voltage, ensuring that electrical energy is continuously delivered to various end users.

IV. Analysis of the Structure of Waterproof Cables

Fine Structure of Single-core Cables: For single-core cables, first, a semiconductive water-blocking tape is carefully wrapped around the insulation shielding layer.

This layer acts like a sensitive "moisture detector" and starts to play a role when moisture first appears.

Then, an ordinary water-blocking tape is wrapped around the outside to further strengthen the waterproof barrier.

Subsequently, the outer sheath is extruded to complete the "last mile" of external protection.

It is worth mentioning that to ensure full contact between the metal shielding layers, only a single-conductive water-blocking tape is wrapped around the outside of the insulation shielding layer, and no additional water-blocking tape is wrapped outside the metal shielding layer.

In the filling process, depending on the level of waterproof performance required, ordinary filling or water-blocking filling can be flexibly selected.

The materials of the inner lining layer and the outer sheath are the same as those described for ordinary single-core cables to ensure the coordinated stability of the overall structure.

The "Waterproof Secret Weapon" of Aluminum-plastic Composite Tape: By ingeniously longitudinally wrapping an aluminum-plastic composite tape layer inside the outer sheath or the inner lining layer, a dense waterproof layer is created. This structure is like putting a "waterproof armor" on the cable.

With the excellent barrier properties of the aluminum-plastic composite tape, it effectively blocks the penetration of water from all directions, greatly enhancing the waterproof ability of the cable.

Direct Protection of HDPE Outer Sheath: 

Directly extruding an HDPE (High-Density Polyethylene) outer sheath on the outside of the cable is a simple yet efficient waterproof strategy.

The HDPE material itself has excellent waterproof and moisture-proof properties.

It tightly wraps around the surface of the cable, forming a solid protective shell to keep water out. Especially for XLPE (Cross-Linked Polyethylene) insulated cables with a voltage level above 110kV, a metal sheath is used to meet strict waterproof requirements.

The metal sheath is like an "impenetrable wall", with complete impermeability and excellent radial water-blocking performance.

Common types include hot-pressed aluminum sleeves, hot-pressed lead sleeves, welded corrugated aluminum sleeves, welded corrugated steel sleeves, and cold-drawn metal sleeves. Different types are suitable for different scenarios, providing personalized waterproof protection for cables.

V. Decoding Waterproof Forms

Longitudinal Water-blocking Mechanism:

The longitudinal water-blocking of waterproof cables is usually achieved by using key materials such as water-blocking yarns, water-blocking powders, and water-blocking tapes.

These materials contain a that can expand when encountering water.

When water infiltrates from the cable ends or tiny defects in the sheath, this special material will quickly sense it and expand upon contact with water, just like building "dams" inside the cable one after another, effectively preventing the water from spreading further along the longitudinal direction of the cable and ensuring that the power transmission path is not affected by water.

Radial Water-blocking Strategy:

Radial water-blocking is mainly achieved through two ways.

Firstly, by extruding an HDPE non-metallic sheath, taking advantage of the waterproof properties of the HDPE material to resist water intrusion from all radial directions of the cable.

Secondly, by creating metal sheaths through processes such as hot-pressing, welding, and cold-drawing.

These metal sheaths, with their high strength and low permeability, provide solid radial protection for the cable, ensuring that the cable's radial waterproof performance is foolproof.

VI. Distinguishing between Waterproof Cables and Water-blocking Cables

Characteristics of Waterproof Cables:

As mentioned earlier, waterproof cables focus on comprehensively preventing water from entering the internal structure of the cable.

From the design of the sheath to the selection of materials, every aspect is carefully crafted around the core goal of waterproofing, striving to build an airtight waterproof system.

Characteristics of Water-blocking Cables:

In contrast, the assessment standard for water-blocking cables lies in allowing a certain amount of water to enter the cable interior, but under specified conditions, it is not allowed to penetrate to a specified length.

Water-blocking cables are further divided into conductor water-blocking and cable core water-blocking.

Conductor Water-blocking Structure:

During the process of single wire stranding, water-blocking powders and water-blocking yarns are ingeniously added.

Once the conductor accidentally takes in water, these water-blocking materials will expand upon contact with water and quickly play a "plugging" role to prevent further water penetration. Compared with ordinary conductors, solid conductors have inherently better water-blocking performance due to their denser internal structure.

Cable Core Water-blocking Structure:

When the outer sheath is unfortunately damaged and water enters, the water-blocking tapes in the cable core will respond quickly, expand upon contact with water, and rapidly form water-blocking sections, just like setting up checkpoints inside the cable core to prevent further water penetration.

However, for three-core cables, due to the relatively large and irregular gaps in the middle of the cable core, even if the water-blocking tapes are used to fill them completely, the actual water-blocking effect is still not satisfactory.

Therefore, it is recommended to produce each wire core according to the single-core water-blocking structure and then carry out the cabling operation, which can significantly improve the overall water-blocking efficiency of three-core cables.

VII. The "Part-time" Waterproof Function of Rubber-sheathed Cables

Rubber-sheathed cables also have a certain degree of waterproof performance to some extent, but their main function is not professional waterproofing and can only be regarded as "part-time" waterproofing.

In fact, most electric wires and cables have some degree of waterproofing to varying degrees, but the waterproof level varies depending on the type, structure, and material of the cable.

It should be noted that not all cables are naturally waterproof.

Whether a cable needs to have waterproof functionality completely depends on the requirements of its laying environment.

Generally speaking, cables laid in inland river channels or on the seabed are exposed to harsh water environments with high humidity and strong water pressure for a long time, so they must have strong waterproof capabilities.

Such cables usually are equipped with a longitudinal waterproof isolation layer and mostly need to be armored to ensure that they can operate safely and stably in complex and changeable underwater environments and provide reliable power support for various underwater facilities.

If you need any custom wiring harness, you can contact us.