IEEE 400.2-2024: New VLF Cable Testing Standard Enhances Reliability in Power Distribution

Published: February 20, 2024 | Source: IEEE Standards Association

The Institute of Electrical and Electronics Engineers (IEEE) has released the 2024 edition of its crucial standard: IEEE 400.2-2024. This update significantly improves Very Low Frequency (VLF) field testing of shielded medium-voltage cable systems, boosting fault detection accuracy and ensuring safer, more reliable operation of modern power grids.

What is IEEE 400.2?

IEEE 400.2 defines best practices for VLF withstand and diagnostic tests on shielded extruded dielectric cables rated from 5 kV to 69 kV. These include insulation types such as:

• XLPE (Cross-linked Polyethylene)

• EPR (Ethylene Propylene Rubber)

• TR-XLPE (Tree-retardant XLPE)

VLF testing mimics long-term electrical stress at low frequencies (e.g., 0.1 Hz), making it ideal for acceptance testing, commissioning, and maintenance diagnostics of shielded MV cables.

Key Updates in the 2024 Edition

1. Interactive Format

The new edition features a digital-first format with links to annexes, waveform diagrams, and cable tables — perfect for field technicians and engineers.

2. Enhanced Test Protocols

• Defined new pass/fail criteria for aging cables or those with partial discharge (PD) history.

• Introduced specific voltage levels for cable joints, terminations, and multi-section feeders.

• Recognized alternative waveforms: cosine-rectangular, damped AC, and sinusoidal VLF.

3. Alignment with International Standards

IEEE 400.2-2024 now aligns with major international benchmarks:

• IEC 60502-2 (Power cable installation)

• IEC 60229 (Cable sheath testing)

• CENELEC HD 620 (Medium-voltage cables)

This benefits multinational infrastructure projects and standardizes testing for MV cables and other critical applications.

Why It Matters to the Cable Industry

Cable Manufacturers

Manufacturers of shielded instrument cables and armoured data cables must meet new diagnostic sensitivity levels to pass factory qualification and site commissioning protocols.

Utilities & Installers

Field crews benefit from clearer testing standards, reducing risks like insulation breakdown or undetected partial discharges in underground systems.

Consultants & Project Engineers

IEEE 400.2-2024 will now be part of QA benchmarks in grid-tie projects, industrial plants, and substations, especially where medium-voltage and renewable integration cables are used.

“This revision reflects over a decade of feedback from field operators, utilities, and manufacturers,” said Dr. Larry Koltun, Chair of the IEEE Working Group. “It provides the technical clarity and flexibility needed for modern asset management and fault mitigation.”

For more information on compatible MV Cables , visit our product catalog.