We all know that the transmission of electricity requires conductors, so the inside of the cable is a metal conductor, such as; Copper, aluminum, and so on, followed by the protection of metal conductors. Different conductors have different protective skins, usually using insulators such as rubber, silicone rubber, cross-linked polyethylene, polyethylene, polyvinyl chloride, etc., which are used to protect metal conductors.

With the development trend of economic globalization, more and more companies are not paying attention to the principle of proximity when purchasing items. The improvement of purchase spacing, transportation reduction, and storage reduction are also becoming increasingly crucial. The logistics transportation and storage stages of cables and wires are also crucial. Some large and medium-sized manufacturers and enterprises purchase a large amount of cables and wires at once, so many cables and wires are temporarily stored.

Control cable
The model is KVV control cable, and its name is copper core, PVC insulation, and PVC sheath. Its rated voltage index is 450/750. This type of cable is mainly used in mines as a dedicated control cable.
Control cable
The model is KVV22, and its full name is copper core PVC insulated PVC sheathed steel tape armored KVv22 cable. The rated voltage is 450/750. The main application area is in fixed situations such as indoor or cable trenches, direct burial of pipelines, etc. The characteristic of this type of cable is its ability to withstand large mechanical external forces.
The control cable model is KVVRP, which is a copper core PVC insulated PVC sheathed braided shielded control flexible cable. Its rated voltage is 450/750, and it is generally used indoors in areas with mobile shielding requirements.
Control cable
The model is ZRKVVRP, which is a copper core PVC insulated PVC sheathed braided shielded cable. Its rated voltage is 450/750. The main application area is indoors, in some places with mobile shielding and flame retardant requirements.
The control cable model ZRKVV22, its full name is copper core polyvinyl chloride insulated polyvinyl chloride sheathed woven steel strip armored zrkvv22 cable. The rated voltage of this type of cable is 450/750, mainly used indoors, in cable trenches or directly buried pipelines. This type of cable support can be used in some places with flame retardant requirements due to its ability to bear relatively large mechanical external forces.

1、 Overview of control cables
The cables connecting the control center to various systems for transmitting signals or controlling operational functions are collectively referred to as control cables. The early functions of control cables were relatively simple, including: indicator light display, instrument indication, operation of relays and switchgear, alarm interlocking system, etc. In recent years, due to the widespread application of weak current and computer networks, new functions have put forward higher requirements for the selection and application of control cables.
2、 Main series varieties of control cables
The main products of control cables today include PVC insulated control cables, natural styrene butadiene rubber insulated control cables, and polyethylene insulated control cables. In addition, there are also cross-linked polyethylene insulation and ethylene propylene rubber insulation products. The oil immersed paper insulated lead wrapped control cables produced in the early years have been phased out.
The rated voltage of the control cable is expressed in U0/U. The national standard issued in 1998 in China stipulates that the rated voltage of plastic insulated control cables is 450/750V. Foreign countries have proposed 600/1000V products as the conventional product series for control cables. At present, China can also produce 600/1000V plastic insulated control cables. The rated voltage of rubber insulated control cables is specified as 300/500V.
The control cable core is copper core, with a nominal cross-section of 2.5mm and below, with 2-61 cores; 4-6 mm, 2-14 cores; 10mm, 2-10 cores. Control the working temperature of the cable: rubber insulation at 65 ℃, polyvinyl chloride insulation at 70 ℃ and 105 ℃. The control cables used in computer systems generally use PVC, polyethylene, cross-linked polyethylene, and fluoroplastic insulation products.

According to the model, it can be roughly divided into the following categories:
Flexible control cable
1. PVC outer sheath flexible control drag chain cable, flame retardant CC101 bending radius: 8X
2. PVC outer sheath flexible shielded control drag chain cable, flame retardant CC111 bending radius: 10X
3. PVC outer sheath flexible control drag chain cable, flame retardant CC120 bending radius: 5X
4. PVC outer sheath flexible shielded control drag chain cable, flame retardant CC121 bending radius: 8X
5. PUR outer sheath flexible control drag chain cable, oil resistant, hydrolysis resistant, UV resistant, low temperature resistant, wear-resistant, flame retardant CC127 bending radius: 8X
6. PUR outer sheath flexible control shielded drag chain cable, oil resistant, hydrolysis resistant, UV resistant, low temperature resistant, wear-resistant, flame retardant CC117 bending radius: 10X
7. Steel wire woven flexible control drag chain cable, UV resistant, low temperature resistant, wear-resistant, CC158 bending radius: 10X
8. PETP outer sheath flexible control drag chain cable, oil resistant, hydrolysis resistant, UV resistant, low temperature resistant, wear-resistant, flame retardant CC160 bending radius: 5X
9. PETP outer sheath flexible control shielded drag chain cable, oil resistant, hydrolysis resistant, UV resistant, low temperature resistant, wear-resistant, flame retardant CC133 bending radius: 10X
Flexible power cable
10. PVC outer sheath flexible power drag chain cable, flame retardant CC305 bending radius: 8X
11. PVC outer sheath shielded flexible power drag chain cable, flame retardant CC336, bending radius: 10X
12. PETP outer sheath flexible shielded power drag chain cable, oil resistant, hydrolysis resistant, UV resistant, low temperature resistant, wear-resistant, flame retardant CC358 bending radius: 10X
13. PETP outer sheath flexible shielded power drag chain cable, oil resistant, hydrolysis resistant, UV resistant, low temperature resistant, wear-resistant, flame retardant CC371 bending radius: 8X

Electric contact pressure gauges are widely used in industries such as petroleum, chemical, metallurgical, electrical, mechanical, and electromechanical equipment, to measure pressures of various fluid media without explosion hazards.
This instrument can be used in conjunction with relevant electrical equipment (such as relays, frequency converters, etc.) to achieve automatic control and signaling (alarm) of the tested (controlled) pressure system.
The current of the electric contact pressure gauge should not exceed 3a (amperes), otherwise it may cause an accident.
The pressure gauge should be perpendicular to the equipment, and collision and vibration should be prevented during transmission and equipment operation.
The electric contact pressure gauge is suitable for seismic resistant pressure gauge models with ambient temperatures ranging from -40 ℃ to+70 ℃, humidity not exceeding 85%, and vibration or severe pulsation of the measured medium, which does not affect reliable contact and accurate reading.
The electrical circuit of the electric contact pressure gauge should be carefully checked and tested after being installed in the price list and wiring of the electric contact pressure gauge.
When adjusting the given voltage value, the contactor must use a single slot screw tightening tool.
When measuring static load, the contact pressure gauge can use 3/4 of the upper measurement limit. When measuring the alternating load of the pressure gauge manufacturer, 2/3 of the upper measurement limit can be used. In an instant, the upper measurement limit value can be used.
When measuring media with high viscosity and severe shaking pressure, isolation and buffering devices should be added.
Pressure gauges should be regularly calibrated (every three months)
Electric contact pressure gauges should be kept clean and properly maintained during use.
In general, instruments can be used in conjunction with corresponding electrical equipment (such as relays, contactors, etc.) (with contact types such as upper and lower limit, double upper limit, and double lower limit) to achieve automatic control and signaling (alarm) of the pressure system being tested (controlled).
The liquid receiving materials include copper or stainless steel, and users can choose according to their actual usage situation. Suitable for pressure measurement in industries such as petroleum, chemical, metallurgy, and food.

The fire-resistant cable can still maintain the normal operation of the line for a period of time under combustion conditions, which means that in case of a fire, the fire-resistant cable will not burn immediately, and it can still maintain normal power supply for a period of time. This characteristic determines that fire-resistant cables play an important role in modern urban and industrial buildings, as once a fire occurs, the power supply circuits of control, monitoring, guidance, and alarm systems must maintain normal operation.
The main usage scenarios of fire-resistant cables are:
Fire-resistant cables are mainly used in power supply circuits from emergency power supply to user fire-fighting equipment, fire alarm equipment, ventilation and smoke exhaust equipment, guide lights, emergency power sockets, emergency elevators, etc.
When installing fire-resistant cables, staff should pay attention to the following issues:
1. When fire-resistant cables are used in densely packed cable tunnels, cable interlayers, or in flammable locations such as oil pipes and oil depots, Class A fire-resistant cables should be selected first. When these situations are eliminated and the number of cable configurations is relatively small, Class B fire-resistant cables should be selected.
2. Most fire-resistant cables are used as power supply circuits for emergency power supplies, requiring normal operation in case of fire. Due to the sharp increase in ambient temperature during a fire, in order to ensure the transmission capacity of the line and reduce voltage drop, for circuits with long power supply lines and strictly limited allowable voltage drop, the cross-section of the fire-resistant cable should be enlarged by at least one level.
3. Fire-resistant cables cannot be used as high-temperature resistant cables.
4. To reduce the probability of cable joint failure in fire accidents, the number of joints should be minimized during installation to ensure that the line can work normally in a fire. If branch wiring is required, fire protection measures should be taken for the joints.

The main function of wires and cables is to transmit electrical energy, signals, and achieve electromagnetic conversion. For power transmission, such as power cables, overhead lines, etc., for signal transmission, such as shaft cables, and for electromagnetic conversion, such as enameled wires.
Electric cable; power cable: usually composed of several wires or groups of wires.
Power system: The wire and cable products used in the power system mainly include overhead bare wires, busbars (busbars), power cables (plastic cables, oil-paper power cables (basically replaced by plastic power cables), rubber sheathed cables, overhead insulated cables), branch cables, electromagnetic wires, and electrical equipment wires and cables for power equipment.
Information transmission system: The wires and cables used for information transmission systems mainly include local telephone cables, television cables, electronic cables, radio frequency cables, optical cables, data cables, electromagnetic cables, power communication or other composite cables.
Mechanical equipment and instrument systems: Almost all products except for overhead bare wires are used, but mainly power cables, electromagnetic wires, data cables, instrument cables, etc.

(1) Wire: The basic and essential component of a product for transmitting current or electromagnetic wave information.
Main materials: the conductor is the abbreviation of conductive core, which is made of copper, aluminum, copper clad steel, copper clad aluminum and other nonferrous metals with excellent conductivity, and optical fiber is used as the conductor.
There are bare copper wires and tinned wires; Single branch line, stranded wire; Twisted tinned wire.
(2) Insulation layer: A component that is wrapped around the periphery of a wire and serves as electrical insulation. To ensure the normal transmission function of the wire and the safety of external objects and individuals, it is necessary to ensure that the transmitted current, electromagnetic waves, and light waves only travel along the wire and do not flow outward. The potential (i.e., the potential difference or voltage formed on the surrounding object) on the conductor can be isolated. Wire and insulation layer are two basic components that must be present in cable products (excluding bare wires).
Main materials: PVC, PE, XLPE, polypropylene PP, fluoroplastic F, rubber, paper, mica tape
(3) Filler structure: Many wire and cable products are multi-core. After forming these insulated wire cores or pairs into cables (or grouping them multiple times into cables), the first reason is that the appearance is not round, and the second reason is that there is a large gap between the insulated wire cores. Therefore, it is necessary to add a filler structure during cable formation. The filler structure is to make the outer diameter of the cable relatively round, which is conducive to tape wrapping and sheath extrusion.
Main material: PP rope
(4) Shielding: It is a component that isolates the electromagnetic field in the cable product from the external electromagnetic field; Some cable products also need to be isolated from each other between different pairs (or groups) of wires inside them. It can be said that the shielding layer is an "electromagnetic isolation screen". The conductor shielding and insulation shielding of high-voltage cables are used to homogenize the distribution of electric fields.
Main materials: bare copper wire, copper clad steel wire, tinned copper wire
(5) Protective layer: When wire and cable products are installed and operated in various environments, they must have components that protect the overall product, especially the insulation layer, which is called protective layer.
Because insulation materials are required to have excellent electrical insulation properties, it is necessary to require materials with extremely high purity and minimal impurity content; It is often difficult to balance its ability to protect the outside world, so various protective structures must bear the burden of bearing or resisting various mechanical forces, atmospheric environment resistance, chemical or oil resistance, prevention of biological damage, and reduction of fire hazards in the external environment (i.e. installation, usage, and use).

The main characteristics of this type of product are: a wide variety of specifications, a wide range of applications, and a wide range of voltages below 1kV. In the face of special occasions, new products are constantly derived, such as fire-resistant cables, flame-retardant cables, low smoke zero halogen/low smoke low halogen cables, termite resistant, mouse resistant cables, oil resistant/cold resistant/temperature resistant/wear-resistant cables, medical/agricultural/mining cables, thin-walled wires, etc.
Communication cables and optical fibers
With the rapid development of the communication industry, from simple telephone and telegraph cables in the past to thousands of pairs of telephone cables, coaxial cables, optical cables, data cables, and even combined communication cables. This type of product usually has small and uniform structural dimensions, and requires high manufacturing accuracy.
Winding wire
Winding wire is a conductive metal wire with an insulation layer used to wind the coil or winding of electrical products. When it works, a magnetic field is generated through current, or induced current is generated by cutting magnetic lines of force, achieving the conversion of electrical and magnetic energy, thus also known as electromagnetic lines.