Electrical Cable Wire Nyy Nyyhy 3X25mm Cu PVC Power Cable

Conductor Diameter: The 25mm² Copper Conductor is stranded by multiple Copper Wires with a diameter of 0.25mm, with a total outer diameter of about 6.3mm. The stranding pitch is 16-20 times the conductor diameter, which not only ensures Flexibility (minimum bending radius is 12 times the cable outer diameter) but also reduces the influence of skin effect.

Insulation Thickness: The insulation layer thickness of both cables is 1.0mm, using temperature-resistant PVC material. It has been tested to withstand a short-term working temperature of 80°C (duration ≤8 hours), and the normal working temperature does not exceed 70°C.

Overall Outer Diameter: The Nyy Cable has no sheath, so its outer diameter is about 22.5mm; the Nyyhy cable has an additional 1.2mm thick PVC Sheath, so its outer diameter increases to 25.1mm. This difference directly affects the pipe diameter selection during pipe laying (Nyy requires ≥25mm, Nyyhy requires ≥32mm).

Rated Voltage: The rated voltage of both cables is 0.6/1kV (phase voltage 0.6kV, line voltage 1kV), which can be directly connected to the low-voltage distribution network to meet the power transmission needs from the low-voltage side of the transformer (400V) to terminal equipment.

Office Building Trunk Lines: In the strong electric wells of office buildings and commercial complexes, Nyy cables are often used for trunk line laying from the floor main distribution box to the distribution box. Because there is no sheath, it is lighter (about 0.85kg per meter), which is convenient for pipe laying or bridge laying in the ceiling, and the surface of the insulation layer is smooth, which can reduce friction damage with pipes. For example, in the 10th-floor power distribution system of a Grade A office building, the Nyy 3X25mm cable is responsible for the total power supply of 12 offices, stably supporting the simultaneous operation of air conditioners, lighting and office equipment.

Computer Room Equipment Connection: In data center computer rooms, three-phase UPS power supplies of server cabinets are often connected with Nyy cables. Its flexibility can adapt to the dense wiring needs in the computer room, and the flame retardant performance of the insulation layer (UL94 V-0 grade) can reduce the fire risk. In the simulated short-circuit test, the cable insulation layer shrinks but does not drip when exposed to fire, and self-extinguishes within 3 seconds after leaving the fire.

Clean Workshop Power Supply: In clean environments such as food processing plants and pharmaceutical workshops, the smooth insulation surface of Nyy cables is not easy to accumulate dust, which can reduce bacterial growth, and is resistant to corrosion by weak acid cleaning agents commonly used in the workshop (after 48-hour acetic acid solution immersion test, the insulation resistance retention rate is ≥90%).

Outdoor Direct Burial Engineering: In the underground distribution network of residential communities, Nyyhy cables are widely used for lines from transformers to building main boxes. Its PVC sheath has soil corrosion resistance, and when laid in sandy soil, its service life can reach more than 15 years (ordinary unSheathed Cables only 8-10 years). In a residential community project, the cable was buried at a depth of 0.7 meters, and after 3 years of operation, the sheath was found to be undamaged, and the insulation resistance remained above 500MΩ.

Wiring in Humid Environments: Power supply lines in humid areas such as basements and bathrooms need to have moisture resistance. The sheath layer of Nyyhy cables can block water vapor penetration. In the power supply system of charging piles in underground parking lots, the cable is laid through galvanized steel pipes. Even if condensation occurs in the pipes, it can be isolated by the sheath layer to avoid moisture aging of the insulation layer.

Outdoor Lines in Industrial Plants: Nyyhy cables are often used for power supply of outdoor equipment (such as cooling towers, material conveyors) in iron and steel plants and chemical plants. Its sheath layer can resist industrial dust and acid-base fog erosion. In the salt spray test simulating the chemical park environment (5% sodium chloride solution, 48 hours), the sheath surface only showed slight discoloration, no cracks or bubbles.

Electrolytic copper must be tested for purity by a spectrum analyzer, and the content of impurities (such as iron, lead) shall not exceed 0.005%;

PVC particles need to be tested for melt index (1.5-2.5g/10min under 190°C/2.16kg conditions) and thermal aging performance (after 100°C×168 hours, the tensile strength loss rate ≤20%);

Sheath material (Nyyhy only) needs additional weather resistance test (after 1000 hours of xenon lamp aging test, the elongation at break retention rate ≥70%).

Conductor Stranding: A computer-controlled multi-head stranding machine is used to monitor the stranding pitch and tension in real-time, and automatically stop when the deviation exceeds ±5%.

Insulation Extrusion: Equipped with an online laser diameter gauge, which detects the insulation thickness every 0.5 seconds, and the data is transmitted to the control system in real-time. When the deviation exceeds the limit, the extrusion speed is automatically adjusted.

Sheath Extrusion (Nyyhy): Vacuum sizing technology is adopted to ensure uniform sheath thickness, with eccentricity ≤10% (difference between maximum thickness and minimum thickness/average thickness ≤10%).

DC resistance test (≤0.727Ω/km at 20°C, measured by four-terminal method);

Power frequency withstand voltage test (apply 3kV voltage for 5 minutes, no breakdown or flashover);

Insulation resistance test (measured with a 500V megohmmeter, ≥100MΩ·km);

Mechanical performance test (insulation layer tensile strength ≥12MPa, elongation at break ≥150%);

Sheath test (Nyyhy only, environmental stress cracking resistance test ≥1000 hours).

Cable Reel: Galvanized steel reel (diameter 1250mm) is used, with a reel thickness of 5mm, edge height of 180mm, and central shaft hole diameter of 120mm, which can bear a radial pressure of 1000kg (meeting the needs of forklift loading and unloading). The surface of the steel reel is coated with epoxy anti-rust paint, which is free from rust after 48-hour salt spray test.

Inner Packaging: The outer layer of the cable is first wrapped with 2 layers of waterproof kraft paper (weight 80g/㎡), then covered with 0.12mm thick PE film to form a moisture-proof barrier (moisture permeability ≤5g/㎡·24h). Because Nyy cable has no sheath, an additional layer of soft PVC protective cover is added to avoid wear of the insulation layer.

Identification Information: A weather-resistant label is fixed on the side of the steel reel, indicating the product model (such as "Nyy 3X25mm²"), length (default 100m/reel, can be customized to 200m/reel), production batch number, implementation standard, and graphic signs such as "moisture-proof" and "up". The label is printed in both Chinese and English.

It should be stored in a well-ventilated and dry indoor warehouse, away from heat sources (distance ≥1m) and corrosive gases;

The stacking height does not exceed 3 layers, and the bottom steel reel must be padded with wooden frames (height ≥10cm) to prevent ground moisture erosion;

The storage period does not exceed 2 years. If it exceeds the period, the insulation resistance must be re-inspected (≥50MΩ·km can be used).

Road Transportation: Suitable for short-distance transportation within 300km, using closed trucks (carriage temperature ≤40°C). The cable reels are isolated with buffer cotton and fixed with steel belts (at least 4 fixed points per reel). During summer transportation, a sunshade is installed on the top of the carriage to avoid excessive cable temperature (≤50°C) caused by direct sunlight.

Railway Transportation: Suitable for long-distance transportation across regions. The cable reels are fixed in containers (a 20-foot container can hold 10 reels of 100m cables). Silica gel desiccant (5kg per container) is placed in the container to control the relative humidity ≤60%.

Sea Transportation: The main method, departing from Shanghai Port/Shenzhen Port to major ports around the world (such as Dubai Port, Hamburg Port), with a voyage of 20-35 days. The cable reels are reinforced with pallets, moisture-proof membranes are laid in the containers, and each reel of cable is covered with a dust cover (to prevent salt spray intrusion during sea transportation).

Air Transportation: For emergency orders, air freight is adopted (single piece weight ≤300kg). "Handle with care" and "no rolling" signs are affixed on the packaging, which conforms to IATA dangerous goods transportation rules (cables are not dangerous goods, but need to be marked as "non-flammable").

Special spreaders must be used for loading and unloading (to avoid direct contact between steel wire ropes and cable reels), and the lifting speed is ≤0.5m/s to prevent violent shaking;

When manually handling small-length cables (such as 10m/roll), two people need to cooperate to lift them, and dragging the insulation layer or sheath is prohibited.

Whether the packaging is intact (no damage, water stains);

Whether the label information is consistent with the order;

Whether the cable length meets the requirements (allowable deviation ±0.5%);

Whether there are scratches or bulges on the appearance (the damage area of the insulation layer/sheath layer ≤0.5cm² is acceptable).