Price estimation of wires and cables
Cost calculation of wire and cable
To buy high-quality and low-cost wires and cables, we must first have a general understanding of the cost calculation of wires and cables.
The wires and cables we commonly use are insulated wires, also called household cables. The wire structure is simple and the cost is easy to calculate. The wire consists of insulation (polyvinyl chloride) and conductor (copper or aluminum). Let me first introduce the cost calculation method of conductor (copper):
1. First calculate the weight of copper.
The weight of copper = the density of copper (0.0089) * the volume of the conductor (copper). The volume of copper is the same as the volume of the calculated cylinder. Cross-sectional area * length (that is, the length of the wire). To calculate the area of the copper wire, first measure the diameter of the copper wire.
The diameter of the copper wire is 1.772, so the cross-sectional area = (1.772 / 2) square * 3.14 = 2.46.
Area 2..46 * Height 100 * Specific gravity of copper 0.0089 = 2.1894, this is the weight of the copper wire of the wire,
2. The weight of the copper wire * the price of the copper wire (55.7 yuan/kg) = 122 yuan. This is the price of copper wire.
3. Cost calculation of PVC insulation: The total weight of the wire-the weight of copper = the weight of the insulation, and then multiply it by the price of the polyvinyl chloride material (￥8/kg) = the price of the insulation.
4. Adding 5% of the production cost is the cost price of the wire.
Note: The calculation method of aluminum core wire is the same as above. The specific gravity of aluminum wire is 0.0027
Material consumption
The calculation method of copper weight calculation without conversion:
Cross-sectional area * 8.89 = kg/km. Such as 120 square millimeter calculation: 120*8.89 = 1066.8kg/km
1. The amount of conductor:
(Kg/Km)=d^2 * 0.7854 * G * N * K1 * K2 * C /
d = copper wire diameter, G = copper specific gravity, N = number of wires, K1 = copper wire stranding rate, K2 = core wire stranding rate, C = number of insulated core wires
2. The amount of insulating material:
(Kg/Km) = (D^2-d^2) * 0.7854 * G * C * K2, D = insulation outer diameter, d = conductor outer diameter, G = insulation specific gravity, K2 = core wire stranding rate, C = Number of insulated core wires
3. The amount of outer layer: (Kg/Km) = (D1^2-D^2) * 0.7854 * G, D1 = finished outer diameter, D = upper process outer diameter, G = insulation specific gravity
4. The amount of strapping: (Kg/Km) = D^2 * 0.7854 * t * G * Z, D = the outer diameter of the upper process, t = the thickness of the strap, G = the specific gravity of the strap, Z = the overlap rate (1/ 4Lap = 1.25).
5. The amount of winding: (Kg/Km) = d^2 * 0.7854 * G * N * Z, d = copper wire diameter, N = number of wires, G = specific gravity, Z = twisting rate.
6. Knitting dosage: (Kg/Km) = d^2 * 0.7854 * T * N * G / cos θ θ = atan (2 * 3.1416 * (D + d * 2 )) * mesh number / 25.4 / T. d=braided copper wire diameter, T=number of spindles, N=number of spindles, G=specific gravity of copper.
Specific gravity: Copper-8.89; Silver-10.50; Aluminum-2.70; Zinc-7.05; Nickel-8.90; Tin-7.30; Steel-7.80; Lead-11.40; Aluminum foil Mylar-1.80; Paper-1.35; Mylar-1.37 PVC- 1.45; LDPE-0.92; HDPE-0.96; PEF (foam) -0.65; FRPE-1.7; Teflon (FEP) 2.2; Nylon-0.97; PP-0.97; PU-1.21
Cotton tape -0.55; PP rope -0.55; cotton yarn -0.48
Insulating materials other than conductors
1. Sheath thickness: Outer diameter before extrusion × 0.035 + 1. (In line with power cables, the nominal thickness of the single-core cable sheath should not be less than 1.4mm, and the nominal thickness of the multi-core cable should not be less than 1.8mm)
2. Online measurement of sheath thickness:
Sheath thickness = (perimeter after extruding the insulating sheath-perimeter before extruding the sheath)/2 π or sheath thickness = (perimeter after extruding the insulating sheath-perimeter before extruding the sheath) × 0.1592
3. The thinnest point of insulation thickness: nominal value × 90%-0.1
3. The thinnest point of insulation thickness: nominal value×90%-0.1
4. The thinnest point of non-armored shielding sheath: nominal value × 85%-0.1
5. The thinnest point of armored or shielded sheath: nominal value × 80%-0.2
6. Steel wire armor: Number of wires = {π×(outer diameter of inner sheath + wire diameter)} Steel wire diameter×λ) weight ÷ (amount = π×wire diameter² × ρ × L × number of wires × λ
7. Weight of insulation and sheath = π×(outer diameter before extrusion + thickness) × thickness × L ×ρ
8. The weight of the steel strip = {π × (outer diameter before wrapping + 2 × thickness -1) × 2 × thickness × ρ × L} /(1+K)
9. The weight of the tape = {π × (outer diameter before wrapping + number of layers × thickness) × number of layers × thickness × ρ × L / (1 ± K). Among them: K is the overlap rate or gap rate, if it is overlap, it is 1-K; if it is a gap, it is 1+K; ρ is the specific gravity of the material; L is the length of the cable;
To buy high-quality and low-cost wires and cables, we must first have a general understanding of the cost calculation of wires and cables.
The wires and cables we commonly use are insulated wires, also called household cables. The wire structure is simple and the cost is easy to calculate. The wire consists of insulation (polyvinyl chloride) and conductor (copper or aluminum). Let me first introduce the cost calculation method of conductor (copper):
1. First calculate the weight of copper.
The weight of copper = the density of copper (0.0089) * the volume of the conductor (copper). The volume of copper is the same as the volume of the calculated cylinder. Cross-sectional area * length (that is, the length of the wire). To calculate the area of the copper wire, first measure the diameter of the copper wire.
The diameter of the copper wire is 1.772, so the cross-sectional area = (1.772 / 2) square * 3.14 = 2.46.
Area 2..46 * Height 100 * Specific gravity of copper 0.0089 = 2.1894, this is the weight of the copper wire of the wire,
2. The weight of the copper wire * the price of the copper wire (55.7 yuan/kg) = 122 yuan. This is the price of copper wire.
3. Cost calculation of PVC insulation: The total weight of the wire-the weight of copper = the weight of the insulation, and then multiply it by the price of the polyvinyl chloride material (￥8/kg) = the price of the insulation.
4. Adding 5% of the production cost is the cost price of the wire.
Note: The calculation method of aluminum core wire is the same as above. The specific gravity of aluminum wire is 0.0027
Material consumption
The calculation method of copper weight calculation without conversion:
Cross-sectional area * 8.89 = kg/km. Such as 120 square millimeter calculation: 120*8.89 = 1066.8kg/km
1. The amount of conductor:
(Kg/Km)=d^2 * 0.7854 * G * N * K1 * K2 * C /
d = copper wire diameter, G = copper specific gravity, N = number of wires, K1 = copper wire stranding rate, K2 = core wire stranding rate, C = number of insulated core wires
2. The amount of insulating material:
(Kg/Km) = (D^2-d^2) * 0.7854 * G * C * K2, D = insulation outer diameter, d = conductor outer diameter, G = insulation specific gravity, K2 = core wire stranding rate, C = Number of insulated core wires
3. The amount of outer layer: (Kg/Km) = (D1^2-D^2) * 0.7854 * G, D1 = finished outer diameter, D = upper process outer diameter, G = insulation specific gravity
4. The amount of strapping: (Kg/Km) = D^2 * 0.7854 * t * G * Z, D = the outer diameter of the upper process, t = the thickness of the strap, G = the specific gravity of the strap, Z = the overlap rate (1/ 4Lap = 1.25).
5. The amount of winding: (Kg/Km) = d^2 * 0.7854 * G * N * Z, d = copper wire diameter, N = number of wires, G = specific gravity, Z = twisting rate.
6. Knitting dosage: (Kg/Km) = d^2 * 0.7854 * T * N * G / cos θ θ = atan (2 * 3.1416 * (D + d * 2 )) * mesh number / 25.4 / T. d=braided copper wire diameter, T=number of spindles, N=number of spindles, G=specific gravity of copper.
Specific gravity: Copper-8.89; Silver-10.50; Aluminum-2.70; Zinc-7.05; Nickel-8.90; Tin-7.30; Steel-7.80; Lead-11.40; Aluminum foil Mylar-1.80; Paper-1.35; Mylar-1.37 PVC- 1.45; LDPE-0.92; HDPE-0.96; PEF (foam) -0.65; FRPE-1.7; Teflon (FEP) 2.2; Nylon-0.97; PP-0.97; PU-1.21
Cotton tape -0.55; PP rope -0.55; cotton yarn -0.48
Insulating materials other than conductors
1. Sheath thickness: Outer diameter before extrusion × 0.035 + 1. (In line with power cables, the nominal thickness of the single-core cable sheath should not be less than 1.4mm, and the nominal thickness of the multi-core cable should not be less than 1.8mm)
2. Online measurement of sheath thickness:
Sheath thickness = (perimeter after extruding the insulating sheath-perimeter before extruding the sheath)/2 π or sheath thickness = (perimeter after extruding the insulating sheath-perimeter before extruding the sheath) × 0.1592
3. The thinnest point of insulation thickness: nominal value × 90%-0.1
3. The thinnest point of insulation thickness: nominal value×90%-0.1
4. The thinnest point of non-armored shielding sheath: nominal value × 85%-0.1
5. The thinnest point of armored or shielded sheath: nominal value × 80%-0.2
6. Steel wire armor: Number of wires = {π×(outer diameter of inner sheath + wire diameter)} Steel wire diameter×λ) weight ÷ (amount = π×wire diameter² × ρ × L × number of wires × λ
7. Weight of insulation and sheath = π×(outer diameter before extrusion + thickness) × thickness × L ×ρ
8. The weight of the steel strip = {π × (outer diameter before wrapping + 2 × thickness -1) × 2 × thickness × ρ × L} /(1+K)
9. The weight of the tape = {π × (outer diameter before wrapping + number of layers × thickness) × number of layers × thickness × ρ × L / (1 ± K). Among them: K is the overlap rate or gap rate, if it is overlap, it is 1-K; if it is a gap, it is 1+K; ρ is the specific gravity of the material; L is the length of the cable;
