Some Characteristics About Medium Voltage Power Cables

The types of cables are single-core cables, cross-linked polyethylene insulated cables, shielded cables, and bimetallic shielded cables. There are many types, specifications, and models of insulation materials. The types and characteristics of the conductors and insulation materials used are also different.
Different conductors also have different requirements for voltage. There may be large differences between them and they are interconnected.

Therefore, when choosing a cable, you must consider the different characteristics and different requirements between them, and choose a cable product that suits your needs according to different environmental conditions.
The next thing is to pay attention to the specifications and model of the cable, so as not to affect the performance and quality of the use of the cable.
The last thing is to pay attention to the quality of the cable, there is no failure and so on!
These are the important factors that we need to take into account when buying these cable products! So what about the price of these cables?
The types of electrical products are power cables, overhead laying cables, mining cables, rubber-sheathed flexible cables, metal-clad cables, fire-resistant cables for control equipment, coaxial cables for control power, rubber-sheathed cables, fire-resistant wires, coaxial cables, special cables, etc.
The cables used above should generally have the following properties: 1, heat-resistant, flame retardant, 2, high-voltage resistance, 3, cold resistance, 4, electrical properties in line with GB/T20949-1986, GB 19796.1-2003, GB 19007.1-2009, GB 19000.4-20092.1-2012, GB 19983.3-2012, GB 19973.2-2003 and other standards.

Some requirements of cable cores

1. The core can use soft link stranded wire or twisted stranded wire.
2. Cold-resistant cable core must be made of cold-resistant (below 10℃) material. Cold cable sheath should be high and low-temperature resistance (-40 ℃ to +70 ℃) metal sheath or sheath without metal sheath material.
3. High insulation strength cable cores should be used with high content of shaped sheath cable cores or bimetallic sheath cable cores (copper, aluminum).
4. High insulation strength cable cores must use fully insulated shielded conductors or semi-insulated shielded conductors.
5. Corrosion-resistant cable cores in long-term immersion conditions should use non-metallic insulated shielded conductors.
6. Voltage-resistant cable cores should be operated at higher voltages.
7. High insulation strength cable core at rated voltage does not allow the use of overload heating measures as well as the use of mechanical stress generated during the effective protection and adjustment of its strength.
8. High insulation strength cable cores are not allowed to have broken insulation, insulation overheating, insulation aging and conductor damage, etc.

The diameter of the single-core cable is not less than 15 mm, the maximum cross-section is 100mm2, the larger the diameter, the higher the voltage level.
The diameter of the cable has a certain influence on the resistivity between the insulation layers, heat resistance, impact resistance, electrical strength, insulation aging life, cable cold resistance, and the life of the wire and cable.
The thickness of the insulation layer should meet the requirements, and the minimum thickness should be selected considering the influence of the cable structure layer and shield layer on the insulation performance. Conductor material for cross-linked polyethylene (PE) insulation cable should meet the specified temperature requirements.
Insulated cable temperature increase leads to the melting of the insulation material and the temperature that causes the melting of the insulation material is related to the relative humidity and temperature conditions in the air. Air humidity increases, the insulation material melts and causing the insulation material to melt and causing the insulation metal sheath to melt. This causes the insulation material to melt and causes the insulation metal sheath to melt and causes the cable joint to melt, and causes the cable to heat up causing the insulation material to melt. This causes cable failure caused by the heating of cable joints. If the insulation material melts and causes the insulation material to melt. This causes the cable fault to produce a thermal trip, and the cable fault is not found in time and eliminated when the wire on the cable burn will cause a power outage accident. So it is important to choose the right insulation material! But how to pick the right cable for you?
Specifically as follows: For low-voltage power cables, the smaller the diameter the better, but the insulation should not be hard material. Generally, cross-linked polyethylene material should be used when the soft cable insulation material should have a certain thermal resistance, temperature rise and mechanical strength, and other physical properties.

The same specification in the length of the core on each cable should be in line with the provisions.
In the design process, care should be taken not to overload the work. For example, the pressure on the cable becomes larger when operating under overload, so the cable must be protected when working under overload.
In addition, the protection should be strengthened during overload operations. In the overload work also need to do some appropriate protection. Because for low-voltage cables, the general low-voltage users do not have very high requirements for its grounding.
And low-voltage users will also require a high grounding rate to ensure their safety. This can cause some constraints on the voltage level increase. So it is better to choose a high-voltage system for a low-voltage system.
The high-voltage system refers to the two functionally independent power systems through the higher voltage level transmission lines and power equipment to achieve high-voltage power supply (mainly industrial and mining enterprises) and low-voltage power supply (generally by the power supply bureau is responsible for power supply).
The high-voltage system of high-voltage transmission signals, usually used for power supply, has a higher voltage level and is also known as the high-voltage transmission equipment lines (high-voltage transmission equipment) and low-voltage transmission equipment lines (low-voltage transmission equipment) system. And the low-voltage system consists of power supply lines, load management, and substation operation.

Wire cores for shaped wires, and cross-sections should be based on the alignment of the wire in different conductors, insulation materials, and process characteristics to determine.
Cable and busbar connection using rubber flexible wire, according to the actual situation on site, the use of the same cross-section and diameter of the busbar flexible wire or medium-section rubber-sheathed cable. Cable and power transformer, a reactor with the use of copper-core or aluminum-core flexible wire should be selected.

Single-core cable in the commonly used materials are copper, aluminum and copper and other types and varieties, these materials are consistent in electrical performance, but also meet the needs of the normal work of the equipment.
With the rapid development of the new energy industry, wire and cable products have become an important part of major electronic equipment and transportation systems.
The current application of wire and cable products is very wide. Electric power, communications, industrial and mining industrial sectors, as well as the transportation sector, have been commonly used and achieved good results.
First of all, we must ensure that the quality is safe and reliable. Secondly, we should consider the after-sales service in the later production. The third strengthens the construction of independent innovation capacity. Fourth increase brand-building efforts, etc.

Single-core cables are used in different environments are also different, so it is important to understand the relationship between these materials and the scope of application, to choose the appropriate conductor material.
Such as copper conductor: copper wire in low-temperature conditions conductive performance is better. Aluminum conductor: aluminum has a strong conductive effect on the copper, compared with copper conductors, aluminum has better conductive properties and heat resistance. Copper-clad aluminum conductor: copper-clad aluminum has better electrical conductivity and high-temperature resistance characteristics. Copper wire has good electrical conductivity to aluminum and is more adaptable to temperature changes. There is no fusion between the core of the aluminum-clad aluminum conductor and the copper core. Aluminum-clad aluminum conductor (also known as copper-clad aluminum): can be composite with copper or aluminum (can be single core or multi-core) and reduce the insulation resistance.

Medium-voltage power cables commonly used products such as copper, aluminum, steel, etc., specifically including the following.

1. copper-core aluminum stranded wire: suitable for electric power, communications, lighting, lifting, and transportation. Its beautiful appearance, used under different loads, can effectively extend the life of the cable.
2. Aluminum-stranded wire with sheath: It is suitable for various occasions with AC-rated voltage of 220/380 V and below, such as electric power, communication, lighting, etc. Its lightweight has good elasticity and strong corrosion resistance.
   3)Halogen-free PVC insulation: suitable for AC 220/380 V wire (special cable), high-density polyethylene insulation, low-smoke halogen-free insulation core, cross-linked polyethylene insulation, low-smoke halogen-free aluminum alloy (aluminum clad) sheath, etc.
3. Aluminum stranded wire with insulation: suitable for AC rated voltage of 500/1000 V and below on various occasions, it has excellent electrical conductivity, temperature resistance and mechanical properties, aging resistance, non-combustible, acid and alkali resistance, oil resistance, and other properties.
4. Aluminum wire with sheathing strip: It is suitable for various occasions with AC-rated voltage of 400/500 V and below, such as metallurgical equipment in metallurgical and mechanical industries, railroad passenger car parts, and industrial electrical instrumentation devices, etc.
5. Low sulfur aluminum stranded wire with sheath: applicable to various occasions of AC 200/250 V or below (such as factory power facilities and agricultural machinery and equipment) or the specified requirements for the use of cables working in humid environments.