IEC 62067 Cable

IEC 62067 defines a comprehensive four-tier testing regime:

• Routine tests – performed on every manufactured cable length and every prefabricated accessory. These include partial discharge testing (5 pC sensitivity in the 2022 edition), voltage testing, and an electrical test on the cable oversheath.
• Sample tests – conducted on a statistical basis to verify production consistency. These cover conductor resistance, insulation and oversheath thickness measurements, hot set test for XLPE insulation, capacitance measurement, lightning impulse voltage test, and water penetration test.
• Type tests – performed to validate the cable system design. These include electrical tests on the complete cable system, thermal cycling, and impulse voltage withstand tests.
• Prequalification test – the industry’s gold standard for proving long-term reliability. A complete cable system (cable, joints, and terminations) is subjected to 1.7 times the rated voltage through at least 180 heating cycles over one full year. This test only needs to be carried out once for a given design, unless there are substantial changes in material, manufacturing process, or design.

The latest version is IEC 62067:2022 (Edition 3.0), published on April 21, 2022.

Key updates in this edition include:

• A new extension to the prequalification test that requires significantly less time to complete than the full test, helping qualified products reach the market faster
• Tighter partial discharge testing requirements on prefabricated accessories: sensitivity improved from 10 pC to 5 pC

The standard is currently stable until 2030. A Redline version (IEC 62067:2022 RLV) is also available, showing all changes from the previous 2011 edition with track changes.

The standard covers single-core cables with extruded insulation (most commonly super-clean or ultra-clean XLPE) along with their joints and terminations. It specifically applies to fixed installations with rated voltages above 150 kV (U_m = 170 kV) up to and including 500 kV (U_m = 550kV).

Note: It explicitly excludes specialized cable types like submarine cables (which fall under standards like IEC 63026) and transition joints between extruded cables and paper-insulated cables.

IEC 62067 cables are used for high-voltage bulk power transmission in land‑based infrastructure. Specifically, they are designed for fixed installations such as underground ducts, tunnels, trenches, or overhead alternative routes where extruded insulation cables are preferred over traditional overhead lines. These cables carry electricity at the highest voltage levels—above 150 kV up to 500 kV—making them the backbone of national grids, renewable energy connections (offshore wind farms to shore, large solar farms), and urban transmission upgrades where space is constrained and reliability is critical.

The standard covers single‑core cables with extruded insulation (almost always XLPE) and their associated accessories—joints and terminations. It does not apply to submarine cables or transition joints between extruded and paper‑insulated cables.

Selecting the proper cable system depends on balancing your project’s transmission requirements with environmental stresses:

• Voltage Class: Determine if your system requires high-voltage (e.g., 220kV) or extra-high-voltage (e.g., 500kV) thresholds.
• Conductor Sizing & Loss Mitigation: Select the conductor cross-section (typically 400 mm²to 3000 mm²) based on load current. For sizes above 800 mm², specify a Milliken segmented conductor to minimize energy losses from the skin effect.
• Metallic Sheathing: Choose between a Corrugated Aluminum Sheath (for lightweight applications and high short-circuit capacity) or a Lead Sheath (for maximum chemical protection and absolute waterproofing in water-logged tunnels or trenches).
• System Certification: Ensure the manufacturer can supply verified third-party Type Test and PQ reports showing the cable and accessories were tested together.

When manufactured within strict tolerances and installed according to proper civil engineering guidelines, an IEC 62067 cable system has a designed operational lifespan of 40 to 50+ years.

This longevity relies on maintaining continuous conductor operating temperatures at or below the standard 90°C limit (with short-term emergency conditions allowed up to 105°C for limited durations). Because the entire system must survive the intensive 1-year accelerated aging prequalification test before being approved for a project, these cable systems provide long-term asset predictability and an exceptionally low probability of premature dielectric breakdown.