Thread Content
This post was last edited by Sales Support on 2017-8-17 09:36 to introduce the differences and definitions between cables and wires, optical cables, and optical fibers for everyone’s reference. 1. The difference between wires and cables: In fact, there is no strict boundary between “wires” and “cables”. Products with a small number of cores, a small diameter, and a simple structure are generally referred to as wires; those without insulation are called bare wires, while the rest are known as cables ； Wires with a larger cross-sectional area (greater than 6 square millimeters) are called large wires, while those with a smaller area (less than or equal to 6 square millimeters) are called small wires. Insulated wires are also known as cloth wires. A wire consists of one or several flexible conductors, covered with a soft protective layer on the outside ； A cable consists of one or several insulated wires, covered on the outside by a strong outer layer made of metal or rubber. Cables and wires generally consist of three components: a core wire, an insulating covering, and an outer protective layer. The characteristics of commonly used cables are as follows: CEF – ethylene propylene rubber insulation with neoprene sheath; a marine flame-retardant power cable. CVV — marine flame-retardant power cable with PVC insulation and PVC sheath. Wires for oxygen chambers are commonly made from BV, BX, RV, and RVV series wires. Among these, BV refers to copper-core polyvinyl chloride insulated wires; the allowable operating temperature is 65°C, the minimum temperature is -15°C, and the operating voltage is 500V for alternating current and 1000V for direct current. Such wires can be installed indoors or outdoors, either exposed or concealed. BX — copper core rubber-insulated wire, with a maximum operating temperature of 65°C, for use indoors. RV — PVC-insulated single-core flexible wire, with a maximum operating temperature of 65°C and a minimum operating temperature of -15°C. Its operating voltage is 250V for AC and 500V for DC; it is used for internal wiring in instruments and equipment. RVV —— Flexible wire with copper core and PVC insulation and sheathing, allowing a continuous operating temperature of 105°C; it can operate at an alternating voltage of 500V and a direct current voltage of 1000V. It is suitable for use in humid environments where high mechanical protection is required, as well as in situations involving frequent movement and bending. In fact, there is no strict distinction between “wires” and “cables”. Products with a small number of cores, a small diameter, and a simple structure are generally referred to as wires; those without insulation are called bare wires, while the rest are known as cables ； Wires with a larger cross-sectional area (greater than 6 square millimeters) are called large wires, while those with a smaller area (less than or equal to 6 square millimeters) are called small wires. Insulated wires are also referred to as cloth wires; this classification is simple and easy to understand!! Cables generally have more than two layers of insulation, are usually multi-core in structure, are wound around cable reels, and their length is typically greater than 100 meters. Wires are generally single-layer insulated, single-core, packed in rolls of 100 meters, with wire spools. Common cable types: VV denotes polyvinyl chloride insulation (first V) and polyvinyl chloride sheath (second V). YJV22 means cross-linked polyvinyl chloride insulation (YJ), polyvinyl chloride sheath (V), and steel tape reinforcement (22). Cables with “ZR” or “FR” added to the designation are flame-retardant cables (wires). Adding an “L” simplifies the designation of aluminum wire cables: BVV–copper wire with polyvinyl chloride insulation and sheath; BV–copper wire with polyvinyl chloride insulation; BYJ–copper core wire with cross-linked polyolefin insulation; BVR–soft copper wire with polyvinyl chloride insulation; BX–copper wire with rubber insulation; RHF–soft copper wire with neoprene sheath. Those with a small diameter are called “threads”” ； Those with a large diameter are called “cables”. Those with a simple structure are called “lines”” ； Those with a complex structure are called “cables”. But as its scope of use expands, many varieties have \"cables within wires\" and \"wires within cables\". So there is no need for a strict distinction. In everyday usage, people refer to household cloth wires as wires, and power cables as simply cables. Wires and cables mainly include bare wires, winding wires, power cables, communication cables and optical fibers, as well as those used in electrical equipment. 2. Difference between cables and optical fibers: Cable: When a telephone converts sound signals into electrical signals, these signals are transmitted over a line to the switch; from there, the switch uses the same line to send the electrical signals directly to another telephone for reception. The line used in this process of communication is the cable. The cable mainly consists of copper conductors. The core wire diameter comes in 0.32 mm, 0.4 mm, and 0.5 mm; the larger the diameter, the stronger the communication capability ； There are also types classified by the number of core wires: 5 pairs, 10 pairs, 20 pairs, 50 pairs, 100 pairs, 200 pairs, and so on. The number of pairs mentioned here refers to the maximum number of users that the cable can support ； There are also those classified by packaging; I’m not very familiar with that. Cables: They are large in volume and weight, have poor communication capabilities, and can only be used for short-distance communication. Optical cable: When a telephone converts sound signals into electrical signals, these signals are transmitted over the lines to a switch. The switch then sends these electrical signals to an optoelectronic conversion device (which converts electrical signals into optical signals), which in turn transmits the optical signals over the lines to another optoelectronic conversion device (which converts optical signals back into electrical signals). From there, the signals reach the switching equipment and finally another telephone, where they are received. The cable connecting the two photoelectric conversion devices is an optical fiber cable. It is said that it varies only in the number of core wires, with options such as 4, 6, 8, 12 pairs, and so on. Optical cables: They have advantages such as small size and weight, low cost, large communication capacity, and strong communication performance. Due to various factors, it is currently used only for long-distance and point-to-point (i.e., between two switching centers) communication transmission. The difference between them: the inside of the cable consists of copper conductors ； The inside of an optical cable is made of glass fibers. An optical cable for communication is a type of communication line in which a certain number of optical fibers are arranged in a specific pattern to form the core of the cable; it is covered with a sheath, and some versions also have an outer protective layer, all of which serve to enable the transmission of optical signals. Field tests have been conducted in Shanghai, Beijing, Wuhan, and other places. Not long after, it was tested as an inter-office trunk line within the city’s telephone network; after 1984, it was gradually used for long-distance lines, and single-mode fiber began to be employed. Communication optical cables have a greater transmission capacity than copper cables. They allow for longer relay distances, are smaller in size and lighter in weight, and are free from electromagnetic interference. Since 1976, they have become the backbone of wired transmission systems for long-distance trunk lines, urban relays, undersea communications in coastal and transoceanic areas, as well as local area networks and private networks. They are also being utilized in urban customer loop wiring networks, providing transmission paths for fiber-to-the-home and Broadband Integrated Services Digital Networks.