I. Basic Definition and Model Designation
Model breakdown: YJY 26/35kV
1. YJ: Cross-linked polyethylene (XLPE) insulation
2. Y: Polyethylene (PE) outer sheath
3. 26/35kV: Rated voltage \(U_0/U\)=26/35kV, system nominal line voltage 35kV, system maximum operating voltage 40.5kV, classified as a 35kV high-voltage cable
Key features: No armor layer, no steel tape / steel wire armor; sheath material is PE (different from the PVC sheath of the YJV model)
II. Core Technical Parameters and Operating Characteristics
1. Standard: GB/T 12706.3-2020
2. Long-term allowable conductor operating temperature: 90°C
3. Short-circuit ≤5s limit withstand temperature: 250°C
4. Minimum ambient temperature for installation: ≥0°C
5. Minimum bending radius: ≥20 times the cable outer diameter
6. Electrical tests: Power-frequency withstand voltage 91kV/5min; lightning impulse withstand voltage 185kV
7. Material property comparison (YJY vs YJV)
PE sheath (YJY): Excellent low-temperature performance, hydrolysis resistance, soil corrosion resistance, good adaptability for low-smoke zero-halogen retrofitting, does not produce large amounts of corrosive hydrogen chloride fumes; lower hardness and better crack resistance than PVC.
PVC sheath (YJV): Lower price, slightly better oil resistance, releases chlorine-containing toxic fumes when burned.
8. Installation restrictions: Unarmored, not suitable for direct burial in soil, unable to withstand external extrusion or impact damage.
III. Main Application Scenarios
1. Suitable for fixed installation in AC 50Hz, 35kV three-phase high-voltage power transmission and distribution:
2. Indoor cable trays, enclosed cable tunnels, and cable trenches in substations
3. Indoor corridors of photovoltaic / wind power booster stations, high-voltage distribution channels in large industrial and commercial parks
4. Urban underground utility tunnels (key areas with requirements for corrosion protection and fume emission indicators)
5. Projects in severe cold regions (PE sheath has greater low-temperature toughness)
Prohibited scenarios: Direct burial in soil, under roadways, outdoor unprotected areas susceptible to mechanical damage; for such conditions, select YJY22 26/35kV (steel tape armored)
IV. Standard Specifications
Mainstream core count: 3-core (general for three-phase distribution); single-core construction optional for high-capacity circuits
Common conductor cross-sections (mm²): 50, 70, 95, 120, 150, 185, 240, 300, 400, 500, 630
