TST CABLE has compiled 100 basic knowledge points about cable materials, covering cable structure, material type, application scenarios and technical standards, etc., to help you quickly master the core knowledge of cable materials.
- Basic structure of cable
Conductor: The core part of the cable, responsible for current transmission, common materials are copper or aluminum.
Insulation layer: Wrap the conductor to prevent current leakage, materials such as PVC, PE, XLPE, etc.
Sheath layer: Protect the cable from mechanical damage and chemical corrosion, commonly used PVC, PE, rubber, etc.
Shielding layer: Reduce electromagnetic interference, common materials are copper tape and braided copper wire.
Filling: Fill the internal gaps of the cable, materials include plastic and hygroscopic materials.
Armor layer: Enhance mechanical strength, such as steel belt armor (such as VV22) and steel wire armor.
Conductor twisting: Multiple strands of fine wires are twisted to improve flexibility, such as RV soft wire.
Insulation thickness: Affects the voltage resistance of the cable and needs to be designed according to the voltage level.
Sheath thickness: determines the wear resistance and tear resistance of the cable.
Shielding coverage: The density of the shielding layer affects the anti-interference effect, such as 85%~95% coverage. - Conductor material
Copper conductor: The best conductivity, commonly used in low-voltage and high-voltage power transmission and signal cables.
Aluminum conductor: Lightweight and low cost, suitable for large-span overhead power transmission.
Copper alloy: such as tin-copper alloy (corrosion resistance), nickel-copper alloy (high temperature resistance).
Tin-plated copper: Strong oxidation resistance, suitable for humid or high temperature environment.
Aluminum-magnesium alloy: High mechanical strength, often used in overhead lines.
Composite conductor: such as copper-clad aluminum, taking into account cost and conductivity.
Single-strand conductor: Hard structure, suitable for fixed installation (such as BV line).
Multi-strand conductor: Flexible structure, suitable for frequent movement (such as RV line).
Conductor cross-sectional area: Directly affects the current carrying capacity, such as 1.5mm², 2.5mm², etc.
Conductor purity: High-purity copper (such as oxygen-free copper) reduces resistance loss. - Insulation materials
PVC (polyvinyl chloride): low cost, suitable for low-voltage cables, but not resistant to high temperatures.
PE (polyethylene): resistant to low temperatures, commonly used in communication cables and optical cables.
XLPE (cross-linked polyethylene): resistant to high temperatures and voltages, used for high-voltage power cables.
EPR (ethylene propylene rubber): high insulation, suitable for power cables and motor leads.
Teflon (polytetrafluoroethylene): resistant to high temperatures (-200℃~300℃), used for high-temperature equipment.
Silicone rubber: wide temperature resistance range (-60℃~200℃), suitable for flexible cables.
Rubber insulation: good elasticity, suitable for mobile devices (such as rubber-sheathed cables).
Low smoke zero halogen material (LSZH): no halogen gas when burning, environmentally friendly cable.
Flame retardant materials: such as flame retardant PVC, delay the spread of flames.
Oil-resistant materials: such as oil-resistant PUR, suitable for industrial environments. - Sheath material
PVC sheath: strong versatility, low cost, but easy to age.
PE sheath: good weather resistance, suitable for outdoor cables.
Rubber sheath: soft and elastic, used for mobile equipment (such as YC cable).
Metal sheath: such as lead-sheathed cable, moisture-proof and mechanical damage-proof.
Fireproof sheath: such as fire-resistant mica tape, used in places with high fire risk.
Waterproof sheath: such as waterproof rubber-sheathed cable, suitable for humid environments.
Cold-resistant sheath: such as silicone rubber sheath, suitable for extremely cold areas.
Corrosion-resistant sheath: adding antioxidants to extend service life.
Transparent sheath: used in occasions where conductors need to be observed.
Abrasion-resistant sheath: increasing thickness or adding wear-resistant materials (such as silicon carbide). - Shielding material
Copper tape shield: continuous winding, high shielding effectiveness (such as P2 shield).
Braided shield: copper wire braiding, good flexibility (such as P shield).
Aluminum foil shield: light, but needs to be used in combination with a braided layer.
Double-layer shielding: copper tape + braiding, suitable for strong interference environment.
Conductive cloth shielding: low cost, but limited shielding effect.
Metalized paper shielding: used for the inner shielding layer of power cable.
Shielding coverage: affects anti-interference ability, needs to be ≥85%.
Shielding grounding: to ensure the effective operation of the shielding layer, reliable grounding is required.
Shielding resistance: low resistance value (<0.1Ω/km) guarantees performance.
Shielding layer thickness: affects mechanical strength and anti-interference effect.
VI. Cable classification
Power cable: transmits electrical energy, such as VV and YJV cables.
Communication cable: transmits signals, such as UTP network cable and optical cable.
Control cable: used for control loops, such as KVVP cable.
Special cables: such as high temperature resistant, fire resistant, and waterproof cables.
Overhead cable: used for power transmission, such as JKLYJ insulated wire.
Rubber sheathed cable: power supply for mobile equipment, such as YC and YZW cables.
Flat cable: saves space, such as YVFB cable.
Shielded cable: anti-interference, such as RVVP cable.
Flame-retardant cable: delay the spread of flames, such as ZR-YJV cable.
Fire-resistant cable: continuous power supply, such as NH-YJV cable.
VII. Cable models and codes
RV: copper core PVC insulated soft wire (such as RV 2×0.75).
BV: copper core PVC insulated hard wire (such as BV 2.5mm²).
YJV: copper core cross-linked polyethylene insulated PVC sheathed power cable.
KVVP: copper core PVC insulated PVC sheathed shielded control cable.
RVVP: copper core PVC insulated shielded soft cable (such as RVVP 2×0.5).
WDZB-BYJ: low smoke halogen-free flame retardant Class B hard wire.
KVV: copper core PVC insulated PVC sheathed control cable.
YCW: heavy rubber sheathed cable, oil-resistant and wear-resistant.
FD: branch cable (such as FD-YJV).
ZR: flame retardant (such as ZR-RVVP).
- Cable application scenarios
Power transmission: high-voltage cables (such as YJV22) are used for transmission networks.
Building wiring: BV, BVR are used for home and building power distribution.
Industrial equipment: RVVP is used for control lines, YC is used for power tools.
Communication network: Category 6 UTP network cable is used for Gigabit Ethernet.
Security monitoring: RVVP is used for camera signal transmission.
Medical equipment: low-smoke halogen-free cables (such as WDZB-BYJ) are used in hospitals.
Rail transit: fire-resistant cables (such as NH-YJV) are used for subway power supply.
Offshore wind power: salt spray-resistant cables (such as PE sheath) are used for wind turbines.
Aerospace: high-temperature cables (such as Teflon insulation) are used in extreme environments.
Smart home: low-smoke halogen-free cables (such as WDZ-BYJ) are used for home wiring. - Cable manufacturing process
Drawing: compressing the metal cross section through a die to form the desired shape.
Twisting: twisting multiple conductors to improve flexibility (such as BVR soft wire).
Extrusion: plastic or rubber coated conductors to form an insulating layer.
Longitudinal wrapping: corrugated aluminum tape is wrapped longitudinally for power cables.
Wrapping: wrapping of tape materials (such as mica tape) for insulation or shielding.
Dip coating: insulating paint or asphalt coating, used in special environments.
Armoring: steel tape or steel wire armoring enhances mechanical strength (such as VV22).
Cabbing: multiple insulated cores are twisted to form a cable structure.
Shielding braiding: copper wire braiding wraps the conductor to reduce electromagnetic interference.
Sheath extrusion: the outer material is extruded to protect the internal structure. - Cable selection and standards
Voltage level: select the cable according to the system voltage (such as 450/750V, 0.6/1kV).
Ambient temperature: Select low temperature resistant (-55℃) or high temperature resistant (200℃) materials.
Mechanical strength: Tensile strength must meet application requirements (such as moored cable > 2000N).
Corrosion resistance: Oil-resistant, acid-resistant and alkali-resistant materials must be selected for chemical environments.
Bending radius: The bending radius of unarmored cable is ≥ 6 times the outer diameter.
National standard certification: such as GB/T 12706 (power cable), GB/T 9330 (control cable).
International standards: IEC 60502 (power cable), IEC 60227 (general cable).
Environmental protection requirements: Low smoke zero halogen (LSZH) cables reduce fire hazards.
Flame retardant grade: A/B/C flame retardant cable (such as WDZB-BYJ).
Life assessment: Predict the cable life based on the aging characteristics of the material (such as PUR insulation layer > 10 years).
