IEC 60364-1:2025

Overview

IEC 60364-1:2025 - Low‑voltage electrical installations - Part 1: Fundamental principles, assessment of general characteristics, and definitions - is the sixth edition of the fundamental part of the IEC 60364 series. It defines the scope and objectives of the series and specifies fundamental safety requirements for low‑voltage electrical installations. This edition (2025) is a technical revision that cancels and replaces the 2005 edition and restructures and renumbers the document for clarity.

Key topics and requirements

• Fundamental principles: Protection for safety, design considerations, selection of electrical equipment, erection and verification practices for low‑voltage installations.
• Assessment of general characteristics: Requirements for maximum demand, diversity, conductor arrangement, and compatibility of characteristics (including electromagnetic compatibility).
• Types of electric systems: Illustrated guidance for AC and DC systems (TN, TT, IT and DC equivalents) to help identify system types and conductor functions.
• New and revised topics (major changes):
  • Expanded scope and restructured content.
  • Inclusion of safety services and standby electric supply systems.
  • Added energy efficiency considerations.
  • Coverage of prosumer electrical installations (generation and consumption by the same user).
  • Requirement for equivalent safety level when using new materials/innovations lacking product standards.
  • Recommendation for periodic verification of protective measures throughout an installation’s lifetime.
  • Introduction of the system‑referencing‑conductor (SRC) symbol (Table 3).
• Definitions and terminology: Updated terms and consistent clause numbering to align with the rest of the IEC 60364 series.

Applications and who uses it

IEC 60364-1:2025 is essential for professionals involved in the lifecycle of low‑voltage electrical installations, including:

• Electrical designers and consulting engineers
• Installation contractors and electricians
• Inspection bodies, verification and testing personnel
• Facility and maintenance managers
• Standards writers, regulators and certification bodies
• Manufacturers and integrators of equipment for low‑voltage systems

Practical uses include guiding design choices, ensuring safety compliance, defining verification and maintenance regimes, and supporting integration of distributed generation, energy efficiency measures, and standby/safety power systems.

Related standards

• This document is the foundational part of the IEC 60364 series (rules for design, erection and verification of low‑voltage installations). Refer to other parts of IEC 60364 for detailed protection measures, wiring systems, and specific installation practices.
• Use IEC resources (IEC Webstore, Electropedia) to locate companion parts and normative references.

Keywords: IEC 60364-1:2025, low‑voltage electrical installations, fundamental principles, safety, prosumer, energy efficiency, system‑referencing‑conductor, standby supply.