Nyy Copper Power Cable 4× 50mm² 4× 70mm²

Both Nyy Copper Power Cable 4×50mm² and 4×70mm² adopt a 4-core Copper Conductor design. The 4×50mm² cable has a single-core conductor cross-sectional area of 50mm², which is formed by stranding multiple Copper Wires with a diameter of 0.2mm-0.3mm. The stranding pitch is 20mm-25mm, the conductor diameter is approximately 8mm, the DC resistance of a single-core conductor at 20℃ is ≤0.387Ω/km, and the overall weight of the 4-core conductor is about 300kg per kilometer. The 4×70mm² Cable has a single-core conductor cross-sectional area of 70mm², also stranded by multiple fine copper wires with a stranding pitch of 25mm-30mm, a conductor diameter of approximately 9.5mm, a single-core DC resistance at 20℃ of ≤0.268Ω/km, and the overall weight of the 4-core conductor is about 420kg per kilometer. Both conductors can withstand a tensile force of ≥8kN, meeting the mechanical strength requirements during laying.

The insulation layer is made of polyvinyl chloride (PVC) material. The insulation layer thickness of the 4×50mm² cable is 1.2mm-1.4mm, with the thinnest part not less than 1.0mm, insulation resistance ≥1000MΩ·km, dielectric loss tangent at 50Hz ≤0.03, and breakdown strength ≥10kV/mm. The insulation layer thickness of the 4×70mm² cable is 1.4mm-1.6mm, with the thinnest part not less than 1.2mm, and the insulation resistance, dielectric loss tangent, and breakdown strength are consistent with those of the 4×50mm² specification. The long-term operating temperature of the PVC Insulation layer is -15℃ to 70℃. It can maintain good Flexibility at -15℃ without cracking, and its performance is stable at 70℃ without softening.

The sheath is also made of PVC material. The sheath thickness of the 4×50mm² cable is 1.4mm-1.6mm, with an average thickness of not less than 1.5mm, the thinnest part ≥1.2mm, tensile strength ≥12MPa, elongation at break ≥150%, and oxygen index ≥30. The sheath thickness of the 4×70mm² cable is 1.6mm-1.8mm, with an average thickness of not less than 1.7mm, the thinnest part ≥1.4mm, and the tensile strength and elongation at break are the same as those of the 4×50mm² specification, with an oxygen index also ≥30. Both sheaths have good acid and alkali resistance. After being immersed in 10% concentration hydrochloric acid and sodium hydroxide solutions for 72h, the performance change rate is ≤20%, and they also have UV resistance and wear resistance.

Both cables have a rated voltage of 0.6/1kV, with a phase voltage of 0.6kV and a line voltage of 1kV. The overall outer diameter of the 4×50mm² cable is approximately 18mm, the bending radius is ≥10 times the outer diameter (about 180mm), and the weight per kilometer is about 500kg; the overall outer diameter of the 4×70mm² cable is approximately 22mm, the bending radius is ≥12 times the outer diameter (about 264mm), and the weight per kilometer is about 700kg. At an ambient temperature of 30℃, the current-carrying capacity of the 4×50mm² cable when laid in air is about 140A-160A, and when directly buried, it is about 110A-130A; the current-carrying capacity of the 4×70mm² cable when laid in air is about 180A-200A, and when directly buried, it is about 150A-170A. Both cables have passed various performance tests of relevant industry standards.

In the field of industrial power distribution, the 4×70mm² cable is suitable for power trunk lines of production lines in industrial plants, such as welding production lines in automobile factories and large processing equipment clusters in machinery processing plants. In these scenarios, the equipment has high power and concentrated electrical loads, and this specification cable can provide stable high-current transmission to meet the normal operation needs of the equipment. The 4×50mm² cable can be used as a branch line in the workshop to supply power to medium-power equipment such as small machine tools, conveyors, and fans. Its flexible bending performance is convenient for laying in equipment-intensive areas, adapting to complex wiring environments.

For building power supply, the 4×70mm² cable is often used in power supply lines of high-power equipment such as central air conditioning systems and elevators in large shopping malls, office buildings and other buildings. The central air conditioning system in large shopping malls has high power and needs to run for a long time, and the high current-carrying capacity and stable performance of the cable ensure its continuous power supply; elevators, as important vertical transportation equipment, have high requirements for power supply reliability, and the 4×70mm² cable can meet their needs. The 4×50mm² cable can be used for floor distribution branches in office buildings to supply power to computers, printers, lighting systems, etc. in offices, and its small outer diameter is convenient for arrangement in small spaces such as walls and ceilings.

In municipal engineering, the 4×50mm² cable is suitable for municipal street lamp systems. Its UV-resistant sheath can resist outdoor sunlight, prolonging its service life. When directly buried, it can withstand soil pressure and slight vibration, meeting the needs of simultaneous power supply for multiple street lamps. The 4×70mm² cable can be used for power supply of large landscape lighting, fountains and other equipment in urban squares, parks and other places, and can cope with the large electrical loads in these places. In addition, in some areas of municipal sewage treatment plants, cables of corresponding specifications can also be selected according to equipment power, and their acid and alkali resistance can adapt to special environments.

In the power supply system of residential communities, the 4×70mm² cable can be used as an incoming cable, accessing the community's distribution center from the municipal power grid, undertaking the main power supply task of the entire community, and its stable performance can ensure the normal electricity use of residents. The 4×50mm² cable is used for distribution branches from the distribution center to each building, supplying power to various electrical equipment in residents' homes, and its flexible laying method can adapt to the complex wiring needs in the community.

The conductor is made of high-purity electrolytic copper with a purity of ≥99.95%. This high-purity copper has excellent conductivity, with a conductivity of up to 58MS/m or more, which can effectively reduce energy loss during current transmission. At the same time, electrolytic copper has good ductility and is not easy to break during stranding, ensuring the integrity and mechanical strength of the conductor. In addition, copper has strong oxidation resistance. In a normal use environment, an oxide film will form on the surface, which can prevent further oxidation and maintain long-term stable conductivity.

The insulation layer is made of polyvinyl chloride (PVC) material, which has good electrical insulation performance, can effectively block current, and prevent faults such as short circuits. PVC material has a wide source, low cost, and good processing performance, which is convenient for extrusion molding. The specially treated PVC insulation layer has improved temperature resistance, and can work stably in the temperature range of -15℃ to 70℃, meeting the needs of use in different environments.

The sheath is also made of PVC material, with antioxidants, UV absorbers, flame retardants and other additives added to the basic formula. Antioxidants and UV absorbers improve the aging resistance of the sheath, making it not easy to age and crack in outdoor or high-temperature environments; the addition of flame retardants gives the sheath certain flame retardant performance, with an oxygen index ≥30, which can delay the spread of flame and reduce the risk of fire. In addition, the sheath also has good chemical corrosion resistance and wear resistance, which can protect the internal structure of the cable from damage by the external environment.

Both cables have a circular structure, with 4 Cores symmetrically distributed around the center. After stranding, a Compact Cable core is formed, and the outer layer is wrapped with a PVC insulation layer and a PVC Sheath in sequence, with an overall smooth and round structure. The surface of the cable is printed with clear marks, including model specifications (such as Nyy Copper Power Cable 4×50mm²), rated voltage, manufacturer, meter marks, etc., which is convenient for users to identify and cut. In terms of color, the sheath is usually black, which has good dirt resistance and heat absorption, suitable for various laying scenarios, and can also blend well with the surrounding environment.

First, high-purity electrolytic copper ingots are smelted into copper liquid, and copper rods with a diameter of 8mm-10mm are made through continuous casting. The copper rods are drawn through a wire drawing machine in multiple passes to make fine copper wires with a diameter of 0.2mm-0.3mm. During the wire drawing process, lubricants are used to reduce friction, ensuring the surface of the copper wires is smooth. Then, according to different cross-sectional specifications, a certain number of copper wires are stranded on a stranding machine, with about 110 copper wires per core for 4×50mm² and about 150 copper wires per core for 4×70mm². During stranding, the stranding pitch is well controlled to ensure the conductor is round and tight. After stranding, the conductor is annealed to eliminate internal stress and improve its flexibility.

The Stranded Conductor enters the insulation extrusion process. PVC Insulation Material is added to the extruder hopper after drying treatment. The extruder barrel is heated in three sections, with temperatures controlled at 140℃-160℃, 160℃-180℃, and 170℃-190℃ respectively to melt and plasticize the PVC material. The molten PVC is uniformly extruded onto the conductor surface through a mold to form an insulation layer, and the mold size is precisely designed according to the insulation thickness. The extruded Insulated Wire core immediately enters a cooling water tank for cooling, and the water temperature is controlled at 20℃-30℃ to quickly shape the insulation layer. After cooling, the thickness and appearance of the insulation layer are inspected to ensure they meet the requirements.

After passing the inspection, the insulated wire cores enter the cabling machine. The 4 insulated wire cores are stranded into a cable according to a certain stranding direction and pitch. The cabling pitch of 4×50mm² is 150mm-200mm, and that of 4×70mm² is 200mm-250mm. During the cabling process, filling materials such as polypropylene ropes are filled in the center and gaps of the cable core to make the cable core round and stable, avoiding friction damage between wire cores. After cabling, a layer of non-woven tape is wrapped around the outer layer of the cable core to play a binding and isolating role, preparing for subsequent sheath extrusion.

The cabled core enters the sheath extruder. PVC sheath material is added to the extruder after mixing and plasticizing, and the barrel temperature is controlled at 150℃-180℃. The molten PVC is extruded onto the surface of the cable core through a mold to form a sheath layer, and the mold is precisely processed according to the cable outer diameter to ensure uniform sheath thickness. The extruded cable is cooled in a cooling water tank, and the water temperature is gradually reduced to avoid internal stress in the sheath due to sudden cooling. After cooling, the cable is pulled to the take-up machine by a tractor and neatly coiled on the cable reel. During the take-up process, the tension is well controlled to prevent the cable from stretching and deforming.

The finished cable needs to undergo strict inspection, including appearance inspection to check whether the sheath surface is smooth, with no bubbles, scratches, depressions and other defects; size measurement to measure the cable outer diameter, insulation thickness, sheath thickness, etc. with a caliper to ensure they meet the specification requirements; electrical performance testing, such as insulation resistance testing, voltage withstand testing (applying 1.8kV voltage for 1min without breakdown), etc.; mechanical performance testing, including tensile strength and elongation at break tests on the sheath; flame retardant performance testing, including bunch burning test to meet relevant flame retardant standards. Only products that pass all tests can leave the factory.

The cable is packaged with wooden cable reels, which are made of high-quality pine wood with high strength and toughness. The diameter of the 500m cable reel for 4×50mm² is 1000mm, and that for 4×70mm² is 1200mm. The structure of the cable reel includes a reel shaft, baffles and spokes. The diameter of the reel shaft is 300mm-400mm, the thickness of the baffle is 25mm-30mm, and there are 8 spokes, evenly distributed to enhance stability. The outer layer of the cable is wrapped with a layer of polyethylene film to prevent dust and moisture contamination during transportation and storage. Plastic protective caps are installed at both ends of the cable to protect the end insulation and conductors from damage.

The cable is neatly coiled on the cable reel. During coiling, the tension is kept uniform to avoid loose or excessive stretching of the cable. Each circle is closely arranged without crossing or overlapping. After coiling, 50mm wide steel strips are used to fix both sides of the cable reel, with 4-6 steel strips evenly distributed on each side. The joints of the steel strips are locked with buckles to prevent the cable from slipping during transportation. Two iron lifting rings are installed on the edge of the cable reel for easy loading and unloading, with a lifting ring strength of ≥50kN. A product label is fixed on the side of the cable reel, made of waterproof and wear-resistant materials, clearly marking product information.

The product label includes: product name "Nyy Copper Power Cable 4×50mm² (or 4×70mm²)", model specification, length, weight, production batch number, implementation standard, production date, manufacturer's name and address, contact information. Warning signs such as "Do not invert", "Handle with care", "Fire and moisture proof", "Avoid sun exposure" are also pasted on the cable reel, reminding operators to handle correctly with a combination of diagrams and text.

Choose an appropriate transportation method according to the transportation distance and quantity. For short-distance transportation (within 500km), road transportation is adopted, using 栏板式 trucks with a carriage length of ≥6m, which can load multiple reels of cables at the same time. The trucks are equipped with fixing devices such as steel wire ropes and tighteners. For long-distance transportation (over 500km), railway transportation can be selected, fixing the cable reels on railway boxcars or flatcars, using the stability of the railway to reduce transportation losses. For export or cross-water transportation, water transportation is adopted, loading the cable reels into containers or fixing them on cargo ships, with moisture-proof and anti-corrosion measures taken.

During transportation, the cable reel must be kept in an upright state, and it is strictly forbidden to lay it flat or upside down to avoid deformation or damage caused by the cable bearing pressure. When loading, wooden pads are placed between the cable reels to prevent mutual collision, and both sides of the carriage are fixed with baffles to limit lateral movement. When loading and unloading the cable reel, cranes or forklifts are used. When lifting, special lifting belts are used to hook the lifting rings, and direct binding of the cable reel with steel wire ropes is avoided to prevent damage to the wooden boards and the cable. During transportation, sudden braking and sharp turns are avoided, the speed is kept stable, and in case of bad weather such as heavy rain and strong wind, the vehicle should stop to take shelter and check the fixing of the cable reel. For long-distance transportation, it is necessary to regularly check whether the cable reel is loose and whether the sheath is damaged, and deal with problems in a timely manner.

After the customer places an order, the sales department confirms the order information, including model specification, quantity, delivery date, delivery location, etc., generates a delivery notice and transmits it to the warehouse and production department. The warehouse checks the inventory. If there is stock, it notifies the quality inspection department to carry out outgoing inspection; if production is needed, the production department arranges the production plan to ensure completion on time. The qualified products after inspection are packaged by the warehouse. After packaging, the transportation company is contacted to sign a transportation contract, clarifying the responsibilities of both parties. When the transportation company picks up the goods, the warehouse and the driver jointly check the product information and quantity, and go through the handover procedures. After shipment, the sales department sends a delivery notice to the customer, including the transportation method, license plate number, waybill number, estimated arrival time, etc., to facilitate the customer's receipt.

2. Delivery Time

For regular specification cables with stock, shipment will be completed within 1-3 working days after receiving the customer's payment or advance payment. For customized products or large-volume orders, the delivery time is determined according to the production cycle, generally 7-15 working days, and the specific time is communicated with the customer in advance. In case of delays caused by force majeure such as raw material shortage and equipment failure, the new delivery time will be negotiated with the customer in a timely manner, and corresponding certificates will be provided.

Customers can apply for samples through phone calls, emails, online platforms, etc., indicating the required model specifications (4×50mm² or 4×70mm²), quantity and purpose. The company will prepare the samples within 2-3 working days after receiving the application. The length of the samples is usually 1m-3m, which can meet the customer's needs for appearance, size, material and performance testing. For special testing needs, longer samples or slices of specific parts can be provided.

Regular samples are provided free of charge, and the customer bears the transportation cost, which can be selected as freight collect or paid in advance. Special customized samples (such as samples with special length or joints) are charged a certain fee, which is calculated according to the sample processing cost, generally 2-3 times the unit price of normal products. The fee can be deducted from the payment after the customer places an order.

Samples are packaged in hard cartons with foam padding inside to prevent damage during transportation. They are delivered by SF Express, DHL and other couriers. The fastest transportation method is selected according to the customer's location. Domestic samples usually arrive within 1-3 days, and international samples within 5-7 days. After delivery, the courier number is provided to facilitate the customer to track the logistics information. After receiving the samples, the technicians can provide testing guidance and parameter explanations.

The product warranty period is 2 years from the date of delivery. During the warranty period, if the product cannot be used normally due to its own quality problems (such as insulation breakdown, sheath cracking, conductor failure, etc.), the company will provide free repair or replacement services. The customer needs to provide purchase vouchers, product photos and fault descriptions, and the technicians will determine the solution after verification.

The company is equipped with a professional technical team to provide customers with full-process technical support, including cable selection suggestions, laying scheme design, installation guidance, etc. Technical questions can be answered by phone, video conference, etc. For large projects, technicians can be dispatched to the site to guide the installation and help solve problems encountered during the laying process. At the same time, product technical manuals, test reports and other materials are provided to help customers better understand and use the products.

If the cable fails during use, the customer can call the after-sales hotline to report the fault, and the after-sales personnel will record the fault situation in detail and respond within 2 hours. For simple faults, technicians can guide the customer to check and solve them by phone or video; for complex faults that need on-site handling, the company will dispatch technicians to the site within 24-48 hours according to the distance to diagnose and repair the fault. If the fault is caused by product quality problems and is within the warranty period, the maintenance cost shall be borne by the company; if it is caused by man-made damage or exceeds the warranty period, reasonable maintenance fees and material fees will be charged.

The company attaches great importance to customer feedback and has set up special feedback channels, such as customer service phone, email, online message, etc. Customers can put forward opinions and suggestions on product quality, service attitude, delivery date, etc. The after-sales department will reply within 5 working days after receiving the feedback, and take corresponding improvement measures according to the feedback content to continuously improve product quality and service level.