Explanations and Representations of Model Specifications for Wire and Cable Take Power Cables as an Example The types and types of power cables mainly include the power cable models of 35kV and below and the product representation method 1 . Capitalization of the first letter of the Pinyin represents the type of insulation, conductor material, inner sheath material, and structural features. For example, Z stands for paper (zhi); L for aluminum (lv); Q for lead (qian); F for phase separation (fen); ZR for flame retardant (zuran); NH for naihuo.

2. The composition of the outer sheath is represented by numbers and there are two digits. No numbers represent unarmored layers and no outer layers. The first digit indicates armor, and the second digit indicates outer cover, as indicated by 41 for thick steel wire armored fibers.

3. The cable type according to the arrangement of the cable structure is generally in order of: insulation material; conductor material; inner sheath; outer sheath.

4. Cable products are represented by type, rated voltage, and specifications. The method is to add Arabic numerals indicating the rated voltage, the number of cores and the nominal cross-sectional area after the model number. For example, VV42-10 3×50 represents copper core, PVC insulated, crude steel wire armored, PVC sheathed, rated voltage 10kV, 3-core, nominal cross-sectional area 50mm2.

The code of each part of the power cable model and its meaning 1 . Insulation type: V represents polyvinyl chloride; X represents rubber; Y represents polyethylene; YJ represents cross-linked polyethylene;

2. Conductor material: L represents aluminum; T (omitted) represents copper.

3. Inner sheath: V stands for PVC sheath; Y polyethylene sheath; L aluminum sheath; Q lead sheath; H rubber sheath; F neoprene sheath.

4. Features: D no trickling; F phase separation; CY oil-filled; P poor oil dry insulation; P shield; Z DC.

5. Control layer: 0 no; 2 double strip; 3 thin steel wire; 4 thick steel wire.

6. The outer layer: 0 no; 1 fiber outer; 2 PVC sheath; 3 polyethylene sheath.

7. The flame-retardant cable is preceded by ZR; the fire-resistant cable is preceded by NH.

Oil-filled cable model and product representation method Oil-filled cable model consists of the product series code and the code of each part of the cable structure. Self-contained oil-filled cable product series code CY. The outer jacket structure is represented by a code combination of reinforcing layer, armor layer and outer layer from inside to outside. The types of insulation, conductor materials, inner sheath code, and sequence of each code and product representation are the same as for 35kV and below power cables. Such as CYZQ102 220/1×4 indicates copper core, paper insulation, lead sheath, radial reinforcement of copper tape, no armor, PVC sheath, rated voltage 220kV, single core, nominal self-contained area of ​​400mm2 Oil-filled cable.

The meaning of the code for the outer sheath of the oil-filled cable is 1. Reinforcement layer: 1 represents the radial reinforcement of the copper strip; 2 represents the radial reinforcement of the stainless steel strip; 3 the radial reinforcement of the steel strip; 4 the stainless steel strip is reinforced longitudinally with radial and narrow stainless steel strips.

2. Armored layer: 0 no armored; 2 steel belt armored; 4 thick steel wire armored.

3. The outer layer: 1 fibrous layer; 2 PVC sheath; 3 polyethylene sheath.

First, the number of square wire and diameter conversion method Knowledge wire specifications are commonly used in the international community there are three standards: US system (AWG), English system (SWG) and our (CWG).

A few square meters is a nominal value stipulated by the national standard. A few square meters are selected by the user according to the load of the wire and cable.

The number of squares in the wire is a verbal expression in the decoration of hydropower construction. The number of squares of wire is often said to have not been added in units of square millimeters.

The square of the wire is actually marked by the cross-sectional area of ​​the wire, that is, the area of ​​the round cross-section of the wire in square millimeters.

In general, the empirical load capacity is when the grid voltage is 220V, and the empirical load capacity per square wire is about 1 kilowatt.

Each square of copper wire can carry 1-1.5 kW, and aluminum wire can carry 0.6-1 kW each square. So an electric appliance with a power of 1 kilowatt is enough to use only one square copper wire.

Specific to the current, short-distance transmission of copper wire generally can carry 3A to 5A of current. Good heat dissipation conditions are 5A/mm2, which is not good for 3A/mm2.

Conversion method:

Knowing the square of the wire, calculate the radius of the wire using the formula for finding the area of ​​the circle:

The square of the wire (square millimeters) = pi (3.14) × the square of the wire radius (mm). Knowing the square of the wire, the same is true for calculating the wire diameter, such as:

2.5 The wire diameter of the square wire is: 2.5÷ 3.14 = 0.8, and the re-opening square yields 0.9mm, so the diameter of the 2.5-square wire is: 2×0.9mm = 1.8mm.

Knowing the diameter of the wire, calculating the square of the wire is also calculated using the formula for finding the area of ​​the circle:

Square of wire = pi (3.14) x square of wire diameter/4

The size of the cable is also squared. Multi-stranded wire is the sum of the cross-sectional area of ​​each wire.

Calculation formula for cable cross-sectional area:

0.7854 × square of wire radius (mm) × number of strands such as 48 strands (0.2 mm per wire radius) 1.5 square lines:

0.785 × (0.2 × 0.2) × 48 = 1.5 square Two, commonly used small-size cable knowledge RVVP: Copper core PVC insulated shielded PVC sheathed flexible cable, voltage 300V/300V 2-24 core. The main quality indicators: wire diameter (including core wire and braided wire, not as thick as possible, with impurity copper to achieve the resistance standard and do very rough), copper core purity, weaving density, lay length.

Uses: instruments, meters, intercom, monitoring, control installation.

RG: Physically foamed polyethylene insulated access network cables are used to transmit data analog signals in a coaxial fiber hybrid network (HFC). This is an American standard and is approximately equivalent to the national standard SYWV series. The main quality indicators: copper wire diameter, insulation thickness, braided material (the market is mostly aluminum-magnesia wire braided, good quality should use tin-plated copper), weaving density.

UTP: LAN cable uses: transmission of telephones, computer data, fire protection, security systems, intelligent building information network. Commonly used UTP CAT 5, UTP CAT 5E with shielded model STP

KVVP: PVC sheathed braided shielded cable Uses: Signal transmission, control, measurement of electrical appliances, meters, and power distribution devices SYWV(Y), SYKV Cable TV, Broadband network-specific cable structure: (Coaxial cable) Single oxygen-free Round copper wire + physical foamed polyethylene (insulation) + (tinned wire + aluminum) + polyvinyl chloride (polyethylene), (equivalent to American Standard RG-6, RG-59). Nowadays, aluminum magnesium wire is used in the market to weave (which cannot be welded and easily oxidized). The core wire is made of copper clad aluminum or copper clad steel. Many people think that the SYWV wire is cheaper than the SYV wire, but in fact it is not the case.

RVV (227IEC52/53) PVC insulated flexible cable (cross-sectional area: 0.5-6.0 core number 1-24) Uses: power lines, signal lines, household appliances, small power tools, instruments and power lighting. As long as the specification line complies with the national standard, the price is not much different, but there is no lack of useful impurities on the market, copper is not enough, a small diameter, a short number of meters, straight (core wire is not twisted or core wire is not twisted, so that the tensile strength is greatly reduced, Resistance increases) to charge. Derivative Model: RVVS: The twisted pitch of this type of core wire is generally used for broadcast systems.

AVVR PVC sheathed flexible cable (cross-sectional area: 0.12-0.5 cores 1-24) Usage: Signal, control. Such as access control signals, control, PTZ control, etc.

HYV, HYA data communication cable (indoor and outdoor) (core diameter 0.5mm, core number 2, 4, 8, etc.) is a telephone line for connection of telephone communication and radio equipment and distribution box for telephone distribution network Wiring and so on. In the market, the diameter of the core is generally 0.4 mm. There is also a difference in the use of steel wire or copper-aluminum alloy. Another common lack of telephone lines.

RV, RVP PVC insulated cables, PVC shielded cables, mainly used for equipment.

RVS, RVB are suitable for connecting cables for household appliances, small electric tools, instruments, meters, and power lighting. RVS can also be used for broadcast lines or in place of RVV cables. RVB can replace the gold and silver wire when the demand is not high.

BV, BVR PVC Insulated Cable Uses: Suitable for electrical instrumentation and power lighting fixed wiring, low price and low resistance. In many occasions to connect the power can be more considerate.

RIB Speaker Cables (Fever Lines, Gold and Silver Cables) Some models of audio cables are marked with the words "6N" and "7N". The meaning is used to indicate the purity of the fever lines made of metal materials. For example, "99.9999%" can be expressed as "6N", which means that the purity is 6-9. The larger the number in front of N, the higher the purity of the audio line. Whether home theater audio equipment requires the use of higher-quality audio cables, the key is to grasp the principle of seeking truth from facts and doing what it can. For the generally popular type (less than 10,000 yuan) audio equipment does not need to deliberately pursue the high quality of the wire, as long as the copper core signal line with a larger general cross-section can be used. For better home theater audio equipment, consider using high-quality audio cables