Commonly used cable, wire, network cable, cable TV line representation

First, the meaning of various commonly used letters

R-connecting flexible cable (wire), soft structure. V-insulated PVC. V-PVC insulation V-PVC sheath B-flat (flat). S-twisted type. A-tin or silver plating. F- high temperature P-bracketed shield P2- copper tape shield P22-steel tape armored

Y-prefabricated, generally omitted, or polyolefin sheathed FD-product category code, refers to the branch cable. The Ministry of Construction standards to be promulgated are represented by FZ, which are essentially the same YJ-XLPE insulated V-PVC insulated or sheathed ZR-flame-retardant NH-refractory WDZ-Halogen-free low-smoke flame retardant WDN-None Halogen low smoke refractory type

Second, cable knowledge

Cables are usually divided into power cables and control cables.

1, the meaning of the cable symbol:

[1]ZR-Flame Retardant, NH-Fire-Resistant, ZA(IA)-Intrinsically Safe

〔2〕 use. Power cable default representation, K-control cable, P-signal cable, DJ-computer cable

[3] Insulation. V-polyvinyl chloride, Y-polyethylene, YJ-crosslinked polyethylene, X-rubber, Z-paper

[4] Conductors. The T-copper core defaults to the L-aluminum core.

[5] Inner sheath (sheath), V-PVC, Y-polyethylene, Q-lead, L-aluminium, H-rubber, HF-non-combustible rubber, LW-wrinkle aluminum sheath, F - Neoprene, N-butyl rubber sheath.

[6] Features. Do not need to indicate that the package type, F-phase lead-phased phase-separated jacket, D-no oil, CY-oil, P-shielded, C-filter, Z-DC

[7] Armored layer. 0-None, 2-double strip (24-steel strip, thick round wire), 3-thick round wire, 4-thick round wire (44-double round wire).

[8] The outer layer. 0-None, 1-fiber layer, 2-PVC sheath, 3-PE sheath.

[9] Rated voltage. Expressed in numbers, kV.

2, examples of commonly used cables:

VV copper core PVC insulated PVC sheathed power cable.

VV22 copper core PVC insulated PVC sheathed power cable .

YJV XLPE insulated, PVC sheathed power cable

3, the meaning of the specification

Specifications using the number of cores, nominal cross section and voltage level

1 Specification of single-core branch cable: Number of cables in the same loop*(1*nominal section), 0.6/1KV,

For example: 4*(1*185)+1*950.6/1KV

2 Multi-core stranded branch cable specification notation: number of identical loop cables* nominal cross section, 0.6/1KV,

For example: 4*185+1*950.6/1KV

3 Multi-core and sheathed branch cable specification notation: number of cable cores × nominal cross-T, such as: 4×25-T

Third, wire knowledge

1, the general meaning of the wire symbol:

[1] Code. B-wire (sometimes not indicated)

[2] Conductors. T-copper (default), L-aluminum, R-soft copper

[3] Insulation. V-PVC, X-rubber, F-chloroprene rubber

[4] Sheath. V-polyvinyl chloride

[5] Others. R-soft wire, P-shielded, B-parallel

2, examples of commonly used wires:

(1), BX, BLX: rubber insulated wire. Fixed laying in indoor or outdoor, bright, dark or wear pipe, as equipment installation line.

(2), BXF, BLXF: neoprene insulated wire. With BX type, good weather resistance, suitable for outdoor use.

(3), BXR: rubber insulated soft wire. Same as BX type, it is only used for soft place when installing.

(4), BXHF, BXLHF: Rubber insulated and sheathed wires. With the BX type, it is suitable for humid places and as an outdoor entrance line.

(5), BV, BLV: PVC insulated wire. Same type BX, but better moisture resistance and weather resistance.

(6), BVR: PVC insulated soft wire. The same type BV is only used for soft installation.

(7), BVV, BLVV: PVC insulated and sheathed wires. Same as Type BV, used in places with high humidity and mechanical protection requirement, can be directly buried in soil

(8), BV-10 V, BLV-105: heat-resistant 105 °C PVC insulated wire. Same as Type BV, used in high temperature environments of 45°C and above.

(9), BVR-105: heat-resistant 105 °C PVC insulated soft wire. With BVR type, used in high temperature environments of 45°C and above.

(10) RV single-core copper core vinyl chloride insulated and insulated cord. For a variety of mobile electrical appliances, meters, telecommunications equipment, their own initiative to use equipment wiring;

Also as an internal mounting line, the ambient temperature during installation is not lower than -15°C.

Fourth, video file transmission material (such as: cable TV) knowledge

Video file signal transmission cable. There are roughly three kinds of coaxial cables, twisted pairs, and optical fibers.

Describe the commonly used coaxial cable knowledge:

1. Classification of Coaxial Cables: Coaxial cables for video file transmission are SYV75-III, SYV75-V, SYV75-7, SYV75-9, SYV75-12

2, the meaning of the letters:

SYV75-5-1 (A, B, C)

SYV75-5-41 (A, B, C)

SYV75-5-2 (A, B, C)

S stands for RF coaxial cable

Y represents polyethylene (PE) insulation

V stands for polyvinyl chloride (PVC) jacket

75 stands for characteristic impedance 75 ohms

5 represents the approximate value of the insulating outer warp

-1, -41 or -2 represents the structural form code. General -1 or -41 represents the inner conductor is single-core; -2 represents the inner conductor is multi-core

A: 64 series B: 96 series C: 128 series

V. Network cable knowledge (five lines)

Network cable classification:

Twisted-pair cables are divided into three types according to their electrical performance: three types, four types, five types, super five types, six types, and seven types of twisted pairs. In principle, the larger the number, the newer the version and the more advanced the technology. The wider the bandwidth, the more expensive it is. When we buy cables for local area networks, we generally purchase five or five cable types because the three or four types of twisted pairs are usually used in 10M/bps Ethernet, and the five types of twisted cables can meet the requirements. The increasingly popular 100M/bps Ethernet, ultra-five twisted pair cable is mainly used for the future Gigabit network, but now it is also commonly used in the local area network, because the price is not much more expensive than the five types of lines, and now there are six Class line, generally used in ATM networks, the company's LAN is not yet recommended.

At present, the three or four types of lines are currently almost absent from the market. If they are present, they do not appear on the three or four types of lines, but are instead sold on five or even five types of lines. This is currently a false five-category line. At most one kind. At present, in common LANs, there are five types, five types or six types of unshielded twisted pairs. In particular, the current Super Category 5 and Category 6 unshielded twisted pairs can easily provide 155Mbps of communication bandwidth, and have advanced Gigabit bandwidth potential, therefore, become the preferred cable for today's horizontal cabling. The twisted pair can be divided into: shielded twisted pair and unshielded twisted pair, most LAN use unshielded twisted pair as the transmission medium for the wiring, the cable is a long distance twisted pair and RJ45 head (Crystal) composition.