YJLV22 3x400mm² Aluminum XLPE Armored MV Cable 8.7/15kV Cost Effective Underground

Cable Designation & Meaning

Construction: Aluminium conductor, XLPE insulation, steel tape armour, PVC sheath, three-core medium voltage power cable.

YJLV22-3×400 mm² (8.7/10 kV) — Medium-Voltage XLPE Insulated Steel-Tape Armored Aluminum Power Cable — Specification & Engineering Data 

1. Overview & Ratings. YJLV22-3×400 — medium-voltage XLPE-insulated, double steel-tape armored, PVC-sheathed aluminum-conductor power cable, three 400 mm² compacted aluminum conductors (L1/L2/L3), rated 8.7/10 kV (Um = 12 kV), 50 Hz; built and tested per GB/T 12701 / IEC 60840, stranding per GB/T 3956. This is a standard MV distribution cable — NOT a fire-resistant cable. Ø ≈ 85 mm, ≈ 6200 kg/km, steel drums.

2. Construction Stack (Conductor → Outer).

3. Electrical Characteristics. R ≤ 0.124 Ω/km at 20 °C (Al 400 mm²); routine test 21 kV AC / 5 min; partial discharge ≤ 10 pC at 12 kV; insulation resistance ≥ 1000 MΩ·km; capacitance ≈ 0.22 μF/km; tan δ ≤ 0.0004 at 90 °C. Reference ampacity ≈ 410 A (free air, 25 °C).

Insulation Data

Electrical Parameters

Reference values: 400 mm² Al at 450 A, 3-phase 10 kV → max balanced load ≈ 7.8 MVA. Voltage drop at 450 A ≈ 44.6 V/km per core (≈0.45% per km at 10 kV).

4. Thermal & Mechanical. 90 °C continuous conductor temperature; 250 °C short-circuit (≤ 5 s); 105 °C overload short duration; operating ambient −40~+50 °C; lay ≥ 0 °C. Double steel tape armor provides crush and mechanical protection for direct burial and tray installation.

Temperature Characteristics

Fire Performance (YJLV22 — Standard)

5. Installation Practice & Handling. Bend ≥ 15 × OD ≈ 1275 mm fixed. Use MV cold-shrink / heat-shrink terminations rated 8.7/10 kV. Qualified personnel only — MV jointing requires specialized training. DC site test 21 kV before energising. At 6200 kg/km, heavy steel drums require mechanical handling.

Mechanical & Installation Parameters

6. Typical Service Applications. Medium-voltage power distribution, transformer feeders (10 kV side), industrial substations, urban grid, wind/solar farm collector circuits, mining plant power — buried, duct, tray, or trench.

7. Testing & QA Regime. Routine: conductor DC resistance, 21 kV AC / 5 min withstand, partial discharge ≤ 10 pC at 12 kV, insulation resistance. Type: impulse voltage 75 kV, tan δ at 90 °C, bending test, heating cycle, dimensional check.

Cable Parameters

Cable Test Parameters

Cable Cross Section Structure

Construction Description

8. Standards & Conformity. GB/T 12701 (MV plastic-insulated power cables); IEC 60840 (XLPE MV cables); GB/T 3956 (conductors). Rated 8.7/10 kV (Um = 12 kV).

9. Packaging, Storage & Logistics. 500 m per steel drum with sealed ends. Continuous marking: YJLV22, 3×400, 8.7/10 kV, GB/T 12701, metre marks. Store dry, indoor, ends sealed.

10. Procurement Specification. State "YJLV22-3×400, 8.7/10 kV" + length. Order matching MV terminations/joints. Confirm against factory test certificate (including partial discharge report).

11. Cable Industry FAQ.

• Q1: What is the difference between YJLV22 and NG-A(BTLY)? YJLV22 is a medium-voltage (8.7/10 kV) power distribution cable with XLPE insulation and steel tape armor. NG-A(BTLY) is a low-voltage (0.6/1 kV) fire-resistant cable with mica tape insulation and aluminum tube sheath. Different voltage, different purpose, different construction — YJLV22 distributes MV power; NG-A(BTLY) survives fire.
• Q2: What does "22" mean? 22 = inner PVC bedding + double steel tape armor + outer PVC sheath. This is standard for cables buried directly or installed in ducts where crush protection is needed.
• Q3: Why use aluminum conductors instead of copper? Aluminum is ~1/3 the weight and ~1/4 the cost of copper. For long-distance MV distribution where conductor cost dominates, aluminum (YJLV) is the standard. YJV (copper) is used where space or weight is constrained.
• Q4: What is the difference between YJV22 and YJLV22? YJV22 uses copper conductors; YJLV22 uses aluminum conductors. Same insulation, same armor, same voltage — only the conductor material differs.
• Q5: Why is there a copper tape screen? At 8.7/10 kV, the electric field at the conductor surface is high. A semi-conducting layer + copper tape screen equalizes the field and prevents corona and partial discharge — essential for MV cable reliability.
• Q6: What is partial discharge? Tiny electrical sparks that occur inside the insulation at defects. MV cables must have ≤ 10 pC at rated voltage to ensure long life. Excessive partial discharge leads to insulation breakdown.
• Q7: Can YJLV22 be used outdoors? Yes — the outer PVC sheath is UV-resistant. For direct burial, the steel tape armor provides crush protection. No additional protection needed.
• Q8: What bending radius is required? 15×OD ≈ 1275 mm for fixed installation. This is much larger than LV cables because the MV insulation is thick and rigid.
• Q9: What is the routine test voltage? 21 kV AC for 5 minutes — this is 2.4× the rated phase voltage (8.7 kV). This proves the cable has no manufacturing defects.
• Q10: Can YJLV22 be used for fire pump circuits? No — YJLV22 is not fire-resistant. Fire pump circuits must use mineral-insulated fire cables (BTTRZ/BTLY). YJLV22 is for standard MV power distribution.
• Q11: How is the cable terminated? MV cold-shrink or heat-shrink terminations rated 8.7/10 kV. The termination must carefully strip the XLPE insulation, insulation screen, and conductor screen in the correct order. Only trained personnel should terminate MV cables.