Low-voltage power cable structure and the difference between four-core and five-core cables

Low-voltage power cables are cables with a rated AC voltage of 1kV and below, which are used to transport electrical energy. In practical applications, there are many models of low-voltage cables, and it is very important to distinguish the various models. This article will introduce the basic meaning of low-voltage power cable models and their differentiation methods in detail.

 

A multi-core cable is a cable with more than one insulated core.

Cables play an important role in electronic products and electronic systems, and are the key link to connect the various functions of electronic products, and are widely used in the fields of aerospace and aviation, as well as naval warships.

Multi-core cables reduce the skin effect of the cable, thus reducing line losses.

Power cables are cables used for the transmission and distribution of electrical energy. Power cables are commonly used in urban underground power grids, power station lead-in lines, internal power supply of industrial and mining enterprises, and underwater transmission lines across rivers and seas.

In the power lines, the proportion of cables is gradually increasing.

Power cables are used in the transmission and distribution of high-power electrical power cable products in the backbone of the power system, including 1-500KV and above various voltage levels, a variety of insulation power cables.

 

Power Cable Structure

The basic structure of a power cable consists of four parts: core (conductor), insulation layer, shielding layer, and protective layer.

Core

The core is the conductive part of the power cable, which is used to transmit electrical energy and is the main part of the power cable.

Insulation Layer

The insulation layer is the core and the earth and the core of different phases are electrically isolated from each other to ensure the transmission of electrical energy, which is an indispensable part of the power cable structure.

Shielding Layer

Power cables of 15KV and above generally have a conductor shield layer and insulation shield layer.

Protective Layer

The role of the protective layer is to protect the power cable from the intrusion of external impurities and moisture, as well as to prevent direct damage to the power cable by external forces.

 

The difference between four-core cable and five-core cable

Different Structure

Five-core cables have one more ground wire than four-core cables, and they both have three fire wires and one zero wire.

The Application Range is Different

Four-core cables are mostly used in three-phase power equipment. And five-core cables are mostly for civil use.

Electrical Performance is Different

Because the four-core cable does not have a ground wire, in the high safety requirements, or high soil resistivity, to the use of electrical equipment without reliable grounding, the need to lead the protection of the ground, the choice of five-core cable and do not have to use four-core cable.

The important difference between the two is that if the insulation of the five-core cable fails, the leakage can be sent to the earth through the grounding wire.

If the four-core cable leaks, the leakage is likely to be transmitted to the user resulting in an electric shock.

 

Low voltage power cables are cables with a rated AC voltage of 1 kV and below, used as a means of transmitting electrical energy. In practice, there are many models of low-voltage cables, and it is very important to distinguish the various models. This article will introduce in detail the basic meaning of low-voltage power cable models and their differentiation methods.

 

Low-voltage Power Cable Model Differentiation Method

 

Common models of low-voltage power cables and their meanings

VV Type Cable

VV-type cable is one of the most common low-voltage power cables.

The V of this model stands for polyvinyl chloride insulation and V stands for polyvinyl chloride sheath.

VV-type cable is suitable for indoor, cable well, and other applications.

VV22 Type Cable

VV22 type cable refers to PVC insulated steel belt armored PVC sheathed cable.

This type of cable has the characteristics of pressure resistance, wear resistance, and corrosion resistance, and is suitable for underground laying occasions such as indoor, outdoor, cable wells, and underground.

YJV Type Cable

YJV-type cable refers to cross-linked polyethylene-insulated PVC-sheathed cable.

Cross-linked polyethylene insulation is an excellent electrical insulation material with stable electrical properties and strong pressure-bearing capacity.

YJV-type cables are suitable for indoor and cable well applications.

YJLV Type Cable

YJLV type cable refers to cross-linked polyethylene insulated polyethylene sheathed cable.

Compared with the VV type cable, the conductor of YJLV type cable adopts an aluminum conductor.

YJLV-type cables are suitable for electric power transmission as well as for cable branch circuits inside buildings, etc.

VV23 Type Cable

VV23 type cable refers to PVC insulated steel belt armored PVC sheathed cable.

Compared with the VV22 cable, the VV23 cable has an additional layer of high-strength steel wire armor.

VV23 type cable is suitable for outdoor, cable well, and underground laying occasions, and has strong corrosion resistance.

 

 

Material

The letters representing the insulation material in the model number of low-voltage power cables are different in each model.

VV-type cables represent polyvinyl chloride insulation, while YJV-type cables represent cross-linked polyethylene insulation.

Therefore, we can distinguish the different models of cables by the material represented in the model number.

Armoring Method

The armoring method of different models of low-voltage power cables varies.

VV22-type cable is armored by a steel belt, and VV23-type cable is armored by steel wire.

Therefore, we can distinguish different models of cables by the armoring method represented in the model number.

Conductor Material

In low-voltage power cables, the conductor material also varies.

The conductor material of VV type cable is more commonly copper conductor, while the conductor material of YJLV type cable is the aluminum conductor. Therefore, we can distinguish the different types of cables by the conductor material represented in the model number.

Applications

Different types of low-voltage power cables are used in different applications.

For example, VV-type cables are suitable for indoor applications and cable wells, while VV23-type cables are suitable for outdoor applications, cable wells, and underground applications. Therefore, we can distinguish different models of cables by the application occasions represented in the model number.

 

In conclusion, the distinction of low-voltage power cable models is very important, because different cable models have different characteristics and application areas. By understanding the meaning and differentiation of various models, we can better select and use low-voltage power cables, to ensure the safety and reliability of power transmission.