IEC 60840:2020

Overview

IEC 60840:2020 - Power cables with extruded insulation and their accessories for rated voltages above 30 kV (Um = 36 kV) up to 150 kV (Um = 170 kV) - Test methods and requirements is the fifth edition of the international test standard for high-voltage extruded‑insulation cable systems. It defines mandatory test methods, acceptance criteria and type/prequalification/routine testing requirements for single‑core and individually screened three‑core power cables and their accessories intended for fixed installations (excluding special cases such as submarine cables and transition joints to paper‑insulated cables).

Key topics and technical requirements

• Scope and applicability: Covers cables with extruded insulation (e.g., XLPE, EPR) and associated accessories for rated voltages from Um = 36 kV up to Um = 170 kV.
• Test regimes: Establishes routine, sample, type and prequalification tests on cables, accessories and complete cable systems.
• Electrical tests: Includes partial discharge, power‑frequency (AC) voltage tests, lightning impulse tests, tan δ (dissipation factor) and heating‑cycle voltage tests among others.
• Mechanical and ageing tests: Specifies bending tests, mechanical property checks before/after ageing, compatibility ageing between materials, and dimensional/insulation thickness verifications.
• Safety and fire performance: Introduces fire‑condition tests (vertical flame spread, smoke density, acidity and conductivity) and the new LSHF oversheath designation ST12.
• New/updated requirements: Requires gas‑immersed cable terminations above 52 kV to be type and routine tested per IEC 62271‑209; adds requirements for composite outdoor termination insulators, modifies bending‑test cylinder diameters per IEC TR 61901:2016, adds a water penetration test in the conductor, and introduces tests on screen sectionalizing insulation for accessories.
• Installation tests: Defines electrical tests after installation (DC oversheath test, AC insulation test) and procedures for conductor temperature determination during tests.

Practical applications - who uses IEC 60840:2020

• Cable and accessory manufacturers - for type approval, routine production testing and specification compliance.
• Testing laboratories and certification bodies - to perform standardized electrical, mechanical and fire performance tests.
• Transmission/distribution utilities and EPC contractors - to specify procurement, validate prequalification samples, and accept installed cable systems.
• Design and QA engineers - for verifying material compatibility, ageing behavior, and commissioning procedures.

Related standards (if applicable)

• IEC 62271-209 - gas‑insulated cable terminations testing (referenced for terminations above 52 kV)
• IEC TR 61901:2016 - referenced for bending‑test dimensions

Keywords: IEC 60840:2020, power cables, extruded insulation, test methods, high‑voltage cables, XLPE, EPR, LSHF, ST12, partial discharge, lightning impulse, type tests, prequalification tests.