High-purity copper (purity ≥99.95%) has extremely low resistivity—at 20°C, the DC resistivity is ≤0.017241 Ω·mm²/m. This means lower energy loss during current transmission: for a 100m, 16mm² NYY cable, the conductor loss is only about 1.05W at full load (45A), which is ideal for scenarios requiring high power transmission efficiency (e.g., data centers, hospitals with high electrical load density).

Copper has excellent thermal conductivity (401 W/(m·K)), allowing rapid heat dissipation. Even in overload conditions (short-term 120% of rated current), it is less likely to overheat and damage insulation.

Aluminum has higher resistivity—at 20°C, the DC resistivity is ≤0.0282 Ω·mm²/m, about 63% higher than copper. To achieve the same current-carrying capacity as NYY, NAXY requires a larger cross-sectional area: for example, a 25mm² aluminum conductor (NAXY) has a similar current-carrying capacity (≈60A) to a 16mm² copper conductor (NYY).

Aluminum’s thermal conductivity (237 W/(m·K)) is about 60% that of copper, so it heats up faster in high-load scenarios. This requires stricter heat dissipation design (e.g., avoiding dense clustering of NAXY cables in cable trays).

Copper is dense (8.96 g/cm³), so NYY cables are heavier. A 100m, 4-core 16mm² NYY cable weighs about 180kg, requiring more labor or mechanical equipment (e.g., cable pullers) for laying, especially in high-rise buildings or narrow spaces.

Copper has good ductility but low Flexibility—over-bending (bending radius <10 times the cable outer diameter) may cause conductor deformation, affecting electrical performance.

Aluminum is lightweight (2.7 g/cm³), only 30% the density of copper. A 100m, 4-core 25mm² NAXY cable (equivalent current-carrying capacity to 16mm² NYY) weighs about 95kg, reducing transportation costs and on-site labor intensity. This is a significant advantage for long-distance laying (e.g., outdoor power supply lines in industrial parks) or projects with limited hoisting capacity.

Aluminum Conductors are usually stranded (bunch-stranded or concentric-stranded) to improve flexibility, with a minimum bending radius of 8-12 times the outer diameter—more adaptable to curved laying paths (e.g., around building corners).

Copper is relatively stable in dry or slightly humid environments, but it may corrode in acidic, alkaline, or high-salt environments (e.g., coastal areas). However, since NYY is often used indoors or protected outdoors, corrosion risks are low, and no additional anti-corrosion treatment is usually needed.

Aluminum is highly reactive and easily forms a dense oxide layer (Al₂O₃) on the surface when exposed to air. While this oxide layer prevents further oxidation in dry environments, it is porous in humid or corrosive environments, leading to conductor oxidation and increased contact resistance. Therefore, NAXY conductors typically undergo tinning treatment (tin layer thickness ≥5μm) or use Aluminum Alloy Conductors (adding magnesium, silicon to improve corrosion resistance) to enhance long-term reliability. In coastal or industrial areas with high chemical pollution, NAXY cables also require additional anti-corrosion sheaths (e.g., polyethylene outer sheaths) for protection.

PVC has limited heat resistance—its long-term allowable operating temperature is only 70°C, and short-term overload temperature (≤5s) cannot exceed 160°C. In high-temperature environments (e.g., indoor cable trenches near boilers, outdoor direct sunlight in summer), PVC insulation is prone to softening, aging, or even cracking, reducing insulation performance and service life.

Application limitation: NYY is not suitable for high-temperature scenarios such as industrial workshops with high ambient temperatures or power supply lines for high-power equipment (e.g., 100kW+ motors).

XLPE has excellent heat resistance due to its cross-linked structure—long-term allowable operating temperature is 90°C, and short-term overload temperature (≤5s) can reach 250°C. This allows NAXY to operate stably in high-temperature environments: for example, in Outdoor Cable trays exposed to summer sunlight (surface temperature up to 60°C), XLPE insulation remains intact, and its insulation resistance (measured with a 2500V megohmmeter) is still ≥1000 MΩ·km (far higher than PVC’s 500 MΩ·km under the same conditions).

Advantage in overload: NAXY can withstand short-term overloads (e.g., 150% of rated current for 1 minute) without insulation damage, making it suitable for scenarios with frequent load fluctuations (e.g., residential communities with peak electricity use in summer).

PVC is prone to aging due to plasticizer volatilization—over time (typically 8-12 years in indoor dry environments), the insulation becomes brittle, and its tensile strength decreases by more than 30%. In outdoor environments with UV radiation, aging accelerates, and the service life may be reduced to 5-8 years. Regular inspection and replacement are required to avoid insulation breakdown.

XLPE’s cross-linked structure prevents molecular chain degradation, so it has strong aging resistance. Its service life in indoor dry environments is 20-30 years, and in outdoor protected environments (e.g., covered cable trenches), it can reach 15-20 years. Even after long-term use, its insulation dielectric loss (tanδ at 50Hz) remains ≤0.0005 (PVC’s tanδ increases from 0.005 to 0.015 after 10 years), ensuring stable electrical performance.

PVC contains chlorine—during combustion or high-temperature decomposition, it releases toxic hydrogen chloride (HCl) gas, which is corrosive to equipment and harmful to human respiratory systems. Although NYY’s outer sheath has flame-retardant properties (conforming to GB/T 18380.1-2008 vertical combustion test), it still poses environmental and safety risks in fire scenarios. Therefore, NYY is gradually being restricted in eco-sensitive areas (e.g., green buildings, hospitals, and schools).

XLPE is halogen-free (no chlorine, bromine), so it does not release toxic gases during combustion. Its smoke density (measured by GB/T 17651-1998) is ≤200 (PVC’s smoke density is ≥400), and the pH value of combustion gases is ≥4.3 (PVC’s pH is ≤3.5, strongly acidic). This makes NAXY compliant with environmental standards such as LEED (Leadership in Energy and Environmental Design) and suitable for eco-friendly projects or enclosed spaces with dense personnel (e.g., subway stations, shopping malls).

Adopts a "conductor + PVC insulation + PVC Sheath" structure—both insulation and sheath are PVC, with a total thickness of 1.5-3.0mm (depending on cross-sectional area). PVC has good impact resistance (tensile strength ≥12MPa, elongation at break ≥150%), but it is prone to cracking at low temperatures (-15°C below). For example, in northern China’s winter, NYY cables laid outdoors may crack if bent, requiring pre-heating before installation.

No additional filling or wrapping layer—between the Insulated Cores, only air gaps exist, which may lead to moisture accumulation in humid environments (e.g., underground garages), reducing insulation resistance over time.

Uses a "conductor + XLPE insulation + semi-conductive water-blocking tape + PVC sheath" structure:

PVC is inherently water-resistant, but the lack of a water-blocking layer between cores means NYY is only suitable for dry or slightly humid environments (e.g., indoor ceiling cavities, covered cable trays). In fully humid environments (e.g., Underground Cable trenches with water accumulation), moisture can seep into the cable core through gaps between insulated cores, causing conductor oxidation and insulation breakdown. For example, a 4-core 16mm² NYY cable immersed in water for 24 hours may see its insulation resistance drop from 1500 MΩ·km to 300 MΩ·km, failing to meet safety standards.

The semi-conductive water-blocking tape and XLPE insulation (low water absorption ≤0.01%) give NAXY IP65-level waterproof performance. Even in underground laying or outdoor rainy environments, it can prevent moisture intrusion. Tests show that a 4-core 25mm² NAXY cable immersed in water for 72 hours maintains an insulation resistance of ≥800 MΩ·km, meeting the waterproof requirements of outdoor power supply lines (e.g., garden lighting, outdoor parking lot power distribution).