Comprehensive summary of wire and cable knowledge

2023-11-17 183

01. Meaning of symbols such as BV and BLV in wires and cables

These symbols are all models of wires. The B series is classified as cloth wires, so B is used at the beginning. Voltage: 300/500V wires are divided into electromagnetic wires and general insulated wires according to their purpose. Insulated wires are also known as cloth wires. Insulated wire (cloth wire) refers to the wire that covers the insulation layer, including various connecting wires and installation wires. V is PVC, polyvinyl chloride, which is (plastic), L is the code for aluminum core, T is the code for copper core (usually omitted), R is the meaning of (soft), to be soft, It is to increase the number of conductors, BV copper core PVC insulated wires, BLV aluminum core PVC insulated wires, BVR copper core PVC insulated flexible wires, and above. The wire structure is as follows: conductor+insulation, taking 2.5mm2 as an example: BV is one with a diameter of 1.78mm and seven with a diameter of 0.68. BLV is one with a diameter of 1.78mm, BVR is 19 with a diameter of 0.41mm. RV copper core PVC insulated connecting flexible wires are softer than BVR, 2.5 and 49 0.25mm copper wires RVV copper core PVC insulated PVC sheathed connecting flexible wires have an additional layer of plastic sheath than RV. In addition, our most commonly used "sheath wire" BVVB copper core PVC insulated PVC sheathed flat cable is 2 BV wires and a layer of white sheath.


02. What is a sheathed wire

Sheath wire refers to a single or multi-core wire with a sheath layer, which is safer with a sheath. To put it bluntly, our most commonly used "sheath wire" is a layer of white polyvinyl chloride sheath with several BV wires inside. This type of wire is usually a copper core wire, with a protective layer on the outside of the wire in addition to an insulation layer. Commonly used sheath wires include RVV, BVV, RVVB, and bvvb models. Sheath wire can be divided into two types: hard sheath wire and soft sheath wire. According to the application environment and shape, it can be divided into circular sheathed wire and flat sheathed wire. Circular sheathed wire is generally multi-core, while flat sheathed wire is generally single core.


03. What is YJV cable (the meaning of YJV cable)

[Full Name] Cross linked Polyethylene Insulated PVC Sheathed Power Cable Y - Polyethylene J - Cross linked V - PVC Sheathed [Number of cores] Single core, 2 core, 3 core, 4 core, 5 core 3+1, 3+2, 4+1, etc. [Specifications] ranging from 1.5 square meters to 240 square meters [Color] Black [Copper] National standard oxygen free copper (red copper) [Sheath] PVC [Standard] This product is produced according to GB12706 "Rated Voltage 35KV Copper and Aluminum Core Plastic Insulated Power Cables" standard, and cables can also be customized according to user needs. 【Usage】 Suitable for indoor use, cable trenches, pipelines, tunnels, etc. It can also be buried in loose soil and cannot withstand external forces. It is generally a main road for circuit transmission, with a rated voltage for power line transmission and distribution. 【General rated voltage】 (U0/U) 0.6/1-26/35kV 【Usage characteristics】 1. The maximum rated temperature of the cable conductor is 90°C, and the maximum temperature of the cable conductor during a short circuit (maximum duration not exceeding 5S) does not exceed 250°C. 2. The ambient temperature during cable laying should not be lower than 0°C.3. The allowable bending radius during cable laying: single core cable should not be less than 15 times the outer diameter of the cable; Multi core cables shall not be less than 10 times the outer diameter of the cable.


04. What cable is YC

YC rubber sheathed cable, also known as heavy-duty universal rubber sheathed flexible cable, is a type of rubber sheathed cable. YC cables are suitable for household appliances, electric tools, and various mobile electrical equipment or light mobile electrical equipment with AC rated voltage below 450/750V, or for temporary construction on construction sites. They can withstand significant mechanical external forces. The long-term allowable working temperature of the wire core should not exceed 60 ℃. Y represents rubber insulation, and C represents heavy-duty cables. The inner sheath is also rubber insulated, and the conductor is copper wire. Rubber sheathed cables are divided into heavy-duty cables (yc cables), medium-sized cables (yz cables), and lightweight cables (YQ cables). The insulation layer of good YC cables is made of pure natural rubber, and the conductors are made of oxygen free copper rods with good conductivity. However, most products in the current market are more or less unable to achieve this quality. YC cable model: YC cables mainly consist of multi-core cables, commonly used being 2-core, 3-core, 4-core, and 5-core, with copper core areas ranging from 0.75 to tens of square meters.


05. Knowledge of BV wires and cables

BV cable: It is a copper core polyvinyl chloride insulated wire and cable, abbreviated as plastic copper wire. It is the most commonly used type of wire and cable and also the type of wire that we come into contact with the most in our daily lives. Conductor material: Oxygen free copper insulation material: PVC color: black, yellow, blue, red, brown, white, etc. Working temperature: 60°C, 70°C, 95°C Rated voltage: 450/750V When laying cables (wires), the ambient temperature should not be less than -15°C. The allowable bending radius of the cable: if the outer diameter (D) of the cable is less than 25mm, it shall not be less than 4D; For cables with an outer diameter (D) of 25mm and above, it should not be less than 6D. The finished cable (wire) and cable core must undergo power frequency spark withstand voltage test. The markings of cables (wires) must comply with the GB6995 standard, and the markings should be clear and wear-resistant. National standard BV wires and cables are used for electrical installations, instruments, decoration, telecommunications equipment, power lighting, and circuits with AC rated voltage of 450/750V and below or DC voltage of 1000V and below. They can be laid in an open or concealed manner. Product standard: GB5023.3-1997 JB8734-98 complies with IEC CCC standards, and the national standard BV cable production certificate must bear the 3C certification mark.


06. What does WDZR-BYJ mean

BYJ: Copper core cross-linked polyethylene insulated cloth wire 450/750VWDZR-BYJ: Copper core flame-retardant halogen-free low smoke cross-linked polyethylene insulated cloth wire 450/750V Product purpose: This product is suitable for fixed wiring of power devices in buildings, electrical appliances, switches, etc. with a rated voltage of 450/750V and below.


07. Explanation of the Meaning of Cable Model

1. General cable symbol answer:

R - Flexible cable (wire) for connection, soft structure.

V - Insulated polyvinyl chloride (PVC insulated or PVC sheathed)

B-flat (flat)

S-twisted pair

A - Tin or Silver Plating

F - High temperature resistance

P-woven shielding

P2- Copper tape shielding

P22- Steel Strip Armor

Y - Prefabricated type

ZR - Flame retardant

NH - Fire resistant type

WDZ - halogen-free low smoke flame retardant type

WDN - Halogen free low smoke fire-resistant type

2. The meanings represented by various universal letters:

A: (Polyamine), installation, aluminum plastic sheath (Alpeth)

B: Flat, half, woven, pump, cloth, styrene (ethylene),

3. Cable knowledge: Cables are usually divided into two types: power cables and control cables.


The meaning of the universal symbol for cables:

〔1〕 ZR flame retardant, NH fire resistant, ZA (IA) intrinsic safety

〔2〕 Purpose

K - Control cable

P-signal cable

DJ - Computer Cable

〔3〕 Insulation layer

V-polyvinyl chloride


YJ cross-linked polyethylene

〔4〕 Conductors. The default representation for T-copper core is L-aluminum core.

〔5〕 Inner protective layer (sheath)

V-polyvinyl chloride


Q-lead package

L-aluminum package


HF - Non combustible rubber

LW - Wrinkle aluminum sleeve

F-chloroprene adhesive

N-butyl rubber sheath