OUZHI Cable
Technical Deep-Dive · Quality Certification · 2026

35 kV Power Cable Engineering: Materials, Standards & Testing Explained

OUZHI Cable (欧智电缆) — 26/35 kV XLPE Medium-Voltage Cable Manufacturer

How a 35 kV XLPE cable is actually engineered layer by layer, which international standards govern its quality, and the factory tests every reel must pass before it leaves our plant. Written by the engineers of the source factory.

Request Technical Documentation View Procurement Guide

Anatomy of a 35 kV Cable — Every Layer Has a Job

A 26/35 kV XLPE power cable is a precision assembly of eight functional layers. Knowing what each layer does helps you specify the right cable and verify the quality of what you receive.

01
Copper / Aluminium Conductor
Class 2 compact stranded copper or aluminium. Copper gives the highest conductivity; aluminium is lighter and more economical for long overhead-to-ground runs.
02
Conductor Screen
A smooth semi-conductive layer over the conductor that eliminates air gaps and equalizes the electric field at the conductor surface.
03
XLPE Insulation
Cross-linked polyethylene rated for 90 °C continuous conductor temperature. Dry-cured, degassed insulation resists partial discharge and thermal ageing.
04
Insulation Screen
Semi-conductive layer over the insulation, firmly bonded, keeping the electric field radial and preventing surface discharges.
05
Metallic Screen
Copper wires plus copper tape. Carries fault current, provides shielding and guarantees a defined electric field around the insulation.
06
Fillers & Binder
For three-core cables, non-hygroscopic fillers and binder tapes make the cross-section circular and stable under load cycling.
07
Armour (SWA)
Galvanized steel wire armour for direct burial, or aluminium wire for lighter installations. Protects against mechanical impact and rodent damage.
08
Outer Sheath
PVC for general use or LSZH (low smoke zero halogen) for indoor and data center installations where fire safety is critical.

OUZHI Cable produces every layer in-house: copper drawing, stranding, triple-extrusion insulation, screening, armouring and sheathing on one integrated production line — that is what "source factory" really means.

International Standards — One Cable, Many Compliance Routes

35 kV cables are accepted across markets under different standards. OUZHI Cable manufactures to the standard required by your destination country and provides full type-test documentation.

StandardMarketScope for 35 kV
IEC 60502-2Global / InternationalExtruded insulation power cables from 6 kV to 30 kV (U), with 36 kV maximum system voltage
GB/T 12706.2ChinaChinese national standard aligned with IEC, covering 35 kV XLPE cables
GOST 31996Russia / CISRussian standard for power cables up to 35 kV with XLPE insulation; required for EAC certification
BS 6622United KingdomBritish standard for 36 kV armoured XLPE cables with metallic screens
VDE 0276Germany / EUGerman series harmonized with IEC for MV cables
ICEA / AEICNorth AmericaInsulated Cable Engineers Association standards used across the US and Canada

Beyond cable standards, every OUZHI Cable production site operates under ISO 9001 quality management, and export batches carry test certificates, certificates of conformity and, where required, EAC / CE documentation.

Factory Testing — What Every Reel Must Pass

Routine tests are performed on 100% of production length. These are the checks a serious 35 kV buyer should ask for in the test report:

Partial Discharge Test
Cable is energized and scanned for internal discharges. Zero-discharge screening at specified sensitivity is the core guarantee of insulation quality.
High-Voltage Withstand
Full cable length withstands test voltage (e.g. 3.5 U0 AC for 30 minutes) proving insulation integrity under stress.
Conductor Resistance
DC resistance measured and verified against the standard, confirming conductor material and cross-section.
Insulation Resistance
Measured after water immersion, proving the insulation is free of moisture and contaminants.
Sheath Spark Test
Outer sheath scanned at high frequency to detect pinholes and mechanical damage along the full length.
Mechanical & Dimensional
Thickness, diameter, tensile and elongation checks on insulation, screen and sheath samples from every batch.

Need proof? We welcome any third-party inspector — SGS, Bureau Veritas, TUV, Intertek — to witness tests at our factory before your shipment leaves.

Why Buyers Trust OUZHI Cable's Quality System

✓
Integrated Production
Copper rod to finished drum in one plant. No outsourcing of critical processes, no hidden subcontracting.
✓
Virgin Materials Only
High-grade copper cathodes and prime XLPE compounds. Material certificates accompany every batch.
✓
Triple-Extrusion Line
Modern CCV triple-extrusion dry-cure line for flawless conductor screen, insulation and insulation screen layers.
✓
100% Routine Testing
Every meter is tested, not sampled. Full reports archived and shipped with the goods.
✓
Traceable Lot Numbers
Drum numbers, lot records and test data are linked, so any issue can be traced to the exact production day and machine.
✓
Global Certification
IEC 60502-2 type tests, GOST 31996 / EAC for CIS, CE where applicable — documentation prepared for customs and project acceptance.

Technical Questions Buyers Ask Us Most

Q: Copper or aluminium conductor — which should I choose?
A: Copper for higher current rating, lower losses and smaller size; aluminium when weight and cost matter more over long distances. We manufacture both from certified material.
Q: Why is LSZH sheath mandatory in data centers?
A: PVC releases dense toxic smoke when burning. LSZH (low smoke zero halogen) emits minimal smoke and no halogen gases, giving people time to evacuate and protecting sensitive electronics.
Q: Single-core or three-core for my project?
A: Three-core saves installation space and cost for shorter runs and grids. Single-core is preferred for very large cross-sections and long circuits where jointing flexibility matters.
Q: Do I always need armour?
A: Armour is required for direct burial, areas with heavy traffic, rocky ground or rodent activity. For protected indoor trays, unarmoured with LSZH is usually sufficient.
Q: What does a partial discharge test actually prove?
A: It detects microscopic voids in insulation that would grow into failure points over years of service. A zero-discharge result at specified sensitivity is the strongest quality signal a 35 kV cable can carry.
Q: How should 35 kV cables be stored on site?
A: Store drums upright on hard ground, sealed ends kept moisture-free, temperature between -5 °C and +50 °C, and away from direct sunlight for LSZH types. We provide handling instructions with every shipment.

Need Technical Documentation or a Factory Audit?

Send us your project voltage, cable schedule or the standard you need to comply with. Our engineers will reply within 24 hours with datasheets, test reports and a factory-direct quotation.

Email: info@ouzcable.com Phone: +998 99 851 6999 WhatsApp: +998 99 851 6999 Telegram: @H99G99
Email: info@ouzcable.com
Phone: +998 99 851 6999
WhatsApp: +998 99 851 6999
Telegram: @H99G99
HQ: China · Export Worldwide
Website: www.ouzcable.com