0.6/1kV ZC-YJV 3x70+1x35mm²‌ Copper XLPE PVC Flame-Retardant Power Cable for Transformer Room LV Outgoing Circuits

Technical Datasheet — ZC-YJV 0.6/1 kV 3×70+1×35 mm²

1. Cable Designation & Meaning

2. Applicable Standards

• GB/T 12706.1-2020​ (equivalent to IEC 60502-1) — Extruded insulation power cables ≤ 1 kV
• GB/T 3956 / IEC 60228​ — Conductors (Class 2)
• GB/T 19666-2019​ — Flame retardant & fire resistant cables (ZC = Class C)
• GB/T 18380.3​ — Bunched flame propagation test, Class C (char ≤ 2.5 m above burner)
• GB/T 16895.15 / IEC 60364-5-52​ — Current-carrying capacity reference for installation

3. Product Components / Construction (inside → outside)

1. Phase conductors (×3)​ — Bare annealed copper, Class 2 stranded compacted circular, 19×∅2.14 mm​ (typical), conductor Ø ≈ 10.0 mm
2. Neutral conductor (×1)​ — Bare annealed copper, Class 2 stranded, 7×∅2.52 mm​ (typical), conductor Ø ≈ 7.0–7.5 mm
3. Conductor screen​ — Not required for 0.6/1 kV; omitted
4. Insulation (×4)​ — XLPE compound, extruded:
   • Phase cores (70 mm²):​ nominal thickness 1.4 mm​ (GB/T 12706, 70–95 mm² class)
   • Neutral core (35 mm²):​ nominal thickness 1.0 mm​ (GB/T 12706, 35–50 mm² class)
   • Colours: phases L1/L2/L3 (brown/black/grey), neutral N (blue)
5. Filler​ — Flame-retardant non-hygroscopic PP/PE filler​ (ZC grade) to form round assembly
6. Binder​ — Flame-retardant glass-fibre / FR tape​ (ZC grade) over laid-up cores
7. Outer sheath​ — Flame-retardant PVC​ compound (ZC grade)
8. Sheath thickness (nominal)​ — 1.9 mm​ (multi-core, 35 mm² and above, 2–5 cores)
9. Sheath colour​ — Black (standard); other colours available on request
10. Armour​ — None
11. Metallic screen​ — None

4. Dimensional Data

5. Insulation Data

• Material:​ XLPE (cross-linked polyethylene)
• Nominal thickness:​ Phase 70 mm² → 1.4 mm; Neutral 35 mm² → 1.0 mm​
• Long-term service temperature:​ 90 °C​ (all cores)
• Short-circuit temperature (≤5 s):​ 250 °C​
• Emergency overload:​ 105–130 °C (limited duration, general XLPE practice)
• Routine test:​ 3.5 kV AC / 5 min; type test 4.0 kV
• Volume resistivity @90 °C:​ ≥ 10¹² Ω·cm (typical XLPE)
• Insulation resistance constant:​ ≈ 3.67 MΩ·km @90 °C

6. Electrical Parameters

7. Temperature Characteristics

• Max. conductor operating temp. (continuous):​ 90 °C​
• Max. short-circuit temp. (≤5 s):​ 250 °C​
• Emergency overload temp.:​ 105 °C (limited duration)
• Min. ambient temp. during installation:​ 0 °C​ (pre-heat below 0 °C)
• Service ambient temperature range:​ −20 °C to +90 °C (sheath/environment)
• Flame retardant class:​ Category C​ per GB/T 19666 (bundled, self-extinguishing, char ≤ 2.5 m)

8. Mechanical & Installation Parameters

• Minimum bending radius (unarmoured multi-core):​ ≥ 15 × overall diameter​ → ≈ 550 mm at Ø36.7 mm
• Maximum pulling tension (copper conductor only):​ 50 N/mm² × (3×70 + 1×35) = 12,250 N total​ (distribute to all 4 cores via pulling eye/sock)
• PVC sheath pulling limit:​ significantly lower — avoid direct sheath grip; use conductor pulling sock
• Direct burial:​ Allowed in non-aggressive soil; sand bed + warning tape, depth ≥ 0.7 m, conduit/duct under roads
• Conduit / duct size:​ Cable OD ≈ 37 mm; use duct ID ≥ 1.5 × OD → ≥ 55 mm (typically 63 mm or larger)
• Cable tray / duct:​ 4-core is stiff at 70 mm²; observe 15D bend radius to avoid core deformation
• Elevation difference:​ No limitation for XLPE insulated cable

9. Material Specification Summary

• Phase conductors:​ Cu ≥ 99.9 % annealed, Class 2, 19×2.14 mm, IEC 60228 / GB/T 3956 (70 mm²)
• Neutral conductor:​ Cu ≥ 99.9 % annealed, Class 2, 7×2.52 mm, IEC 60228 / GB/T 3956 (35 mm²)
• Insulation:​ XLPE, 1.4 mm (70 mm²) / 1.0 mm (35 mm²), rated 90 °C, coloured
• Filler:​ Flame-retardant PP/PE (ZC grade)
• Binder:​ Flame-retardant glass fibre / FR tape
• Outer sheath:​ Flame-retardant PVC (ZC), 1.9 mm nom.
• No armour, no metallic screen, no separate PE core

10. Scope of Application / Usage Range

ZC-YJV 0.6/1 kV 3×70+1×35 mm²​ is intended for fixed installation​ in low-voltage three-phase four-wire (3L+N) power distribution & transmission systems up to 1.2 kV system voltage, where flame-retardant Class C​ performance is required.

Typical applicable locations:

• Three-phase four-wire (TN-C) distribution feeders​ — the standard use of 3×70+1×35 (3L+N, reduced neutral) for three-phase loads with unbalanced neutral current
• Main / sub-distribution boards, floor risers, and feeder circuits in high-rise buildings, commercial complexes, hotels, hospitals, stations and metros​ (where ZC flame-retardant grade is mandated)
• Industrial plants, warehouses, medium machinery, HVAC (air conditioning) and pump/motor feeders​
• Cable trays, cable ducts, cable trenches & shafts in residential / public buildings
• Direct buried routes in non-aggressive soil with low-to-moderate mechanical impact
• Renewable / PV and EV charging station three-phase supply feeders (earthing/neutral arrangement to be confirmed per local code)

Not suitable for:

• Systems requiring separate PE (TN-S) → use 3×70+2×35​ (3L+N+PE) or add a separate PE conductor
• Fire-survival / emergency circuits → use NH-ZC-YJV 3×70+1×35
• Heavy tensile / armour-protected routes → use ZC-YJV22 3×70+1×35
• Single-phase circuits → use 2-core or 3-core
• Highly corrosive / hydrocarbon-rich / long-term submerged environments without extra barrier
• High-current feeders where ~195 A / voltage drop governs → upsize to 3×95+1×50 or larger

11. Packing

• Drum:​ Steel-wooden drum; common length 100–500 m per drum (70 mm² class, shorter lengths typical due to weight/stiffness; ≈ 3.3 t/km)
• HS code (China):​ 8544 4921 (LV power cable, PVC sheath)

Key engineering notes for ZC-YJV 3×70+1×35 mm²

1. 3+1 means no separate PE​ — neutral (35 mm²) is shared as PEN in TN-C, or used purely as N. For TN-S (separate PE), select 3×70+2×35.
2. Mixed insulation thicknesses:​ 70 mm² phase = 1.4 mm​ (70–95 class); 35 mm² neutral = 1.0 mm​ (35–50 class). Do not give both cores 1.4 mm .
3. Sheath = 1.9 mm​ (multi-core ≥ 35 mm² rule) — thicker than the 1.8 mm used for ≤16 mm² multi-core cables.
4. Conductor resistance​ is the compliance limit: 70 mm² ≤ 0.268 Ω/km, 35 mm² ≤ 0.524 Ω/km (GB/T 3956 Class 2) .
5. Ampacity consensus ≈ 195 A (air) / 230 A (buried)​ — source tables vary 178–260 A with laying method and reference temperature. Always correct for grouping, ambient temperature, and conduit/duct.​ At 400 V three-phase, 195 A ≈ 135 kVA theoretical.
6. Weight ≈ 3.3 t/km​ — plan drum handling, tray loading and pulling equipment accordingly.