Many people have heard of power cables and control cables, but they don't know much about the differences between them. Let's take a look at the differences between power cables and control cables. We can understand the difference between power cable and control cable from the aspects of classification, standard and suitable place.
The application range of power cable and control cable is different
Power cables are 0.6/1kv, such as VV and YJV
The control cable is 450/750v, such as KVV and KVVP
Generally, the power cables are all within 5 cores, which are generally used for high voltage. There are many cores for control cables. Sometimes customers have different requirements, usually 37 cores, but there are also more cores.
Commonly used cable classification is divided into five categories:
(1) Wire and bare inner conductor products: refers to only conductors, but no insulation layer and other structures. Such as: copper, aluminum and various composite metal single wires; Twisted wires, flexible wires, profiles and profiles for overhead transmission of various structures, etc.
(2) Electromagnetic wire: A wire that cuts magnetic lines in a magnetic field in the form of a winding to induce a current, or generates a magnetic field with a current, is called an electromagnetic wire. Such as enameled wire, fiber-wound wire, inorganic insulated wire, etc.
(3) Power cable: a wire product used to transmit and distribute high-power electric energy in the trunk line of power system, called power cable. Such as plastic cables of various voltage levels, oil-impregnated paper cables and non-drip cables, etc.
(4) Communication cable: cable for transmitting audio and various telecommunication information above audio. Such as: local telephone cable, long-distance symmetrical communication cable, coaxial communication cable, telephone equipment cable and data cable, etc.
(5) Wires and cables for electrical equipment: wires and cables for power connection that directly transfer electric energy from distribution points of power system to various electrical equipment and appliances. Such as wires and cables for electrical connection and control signals in various industrial and agricultural equipment. This kind of products have a wide range of applications and various varieties, and most of them have to combine the characteristics of the equipment used and the environmental conditions used to determine the structure and performance of the products.
Therefore, in addition to a large number of general products, there are many special and special products. Such as: general insulated wires, installation wires, rubber sheathed flexible cables, control cables, signal cables, special cables for airplanes, automobiles and tractors, electrical and electrical outlet wires, cables for locomotives and rolling stock, wires for radio devices, mining cables, marine cables, agricultural cables, oil mines and exploration cables, cables for field work, wires for various high-voltage DC equipment, flexible cables, etc.
Power cables are used to transmit and distribute large-function electric energy in power system trunk lines, and control cables directly transmit electric energy from distribution points of power system to power supply connection lines of various electrical equipment and appliances. The rated voltage of power cable is generally 0.6/1kV and above, and the control cable is mainly 450/750V. When power cables and control cables of the same specifications are produced, the insulation and sheath thickness of power cables are thicker than that of control cables.
Control cables belong to electrical equipment cables, and power cables are two of the five categories of cables.
The implementation standards of power cables and control cables are different
The standard of control cable is 9330
The standard of power cable is GB12706
The color of the insulated core of the control cable is generally black and printed in white, and the low voltage of the power cable is generally color separated.
Generally, the cross-section of control cables will not exceed 10 square meters, and the power cables are mainly used for power transmission, which are generally large in cross-section.
Due to the reasons mentioned above, the specifications of power cables can generally be larger, up to 500 square meters (the range that conventional manufacturers can produce). However, there are relatively few manufacturers who can do it with a larger cross section, while the cross section of control cables is generally smaller, and the largest one generally does not exceed 10 square meters.
In terms of the number of cable cores, according to the requirements of the power grid, the power cable is generally 5 cores at most, while the control cable is used for transmitting control signals, and the number of cores is more, with 61 cores according to the standard, but it can also be produced according to the requirements of users.
Grounding methods of power cable and control cable are different
Electrical and thermal control cables are shielded and grounded
There are two grounding methods for cable shield, namely, two-point grounding and one-point grounding.
To prevent transient overvoltage, it is better to ground the shielding layer at two points. Grounding at two points causes electromagnetic induction to generate an induced longitudinal current on the shielding layer, which generates a secondary field opposite to the main interference, counteracts the action of the main interference field, and reduces the interference voltage.
Ground both ends of the control cable shield. The ability of shielding layer to reduce induced overvoltage is mainly based on the counteraction of magnetic field generated by shielding layer current to magnetic field generated by interference current. Two ends of the shielding layer are grounded because it is not easy to burn the shielding layer because of the short action time of large short-circuit current and lightning current when short-circuit current and lightning current pass through. If one end of the shielding layer is grounded, there is no current loop, but its ability to prevent overvoltage and anti-interference is very low, so the shielding layer cannot achieve good shielding effect.
