In a TN system, the source transformer neutral is directly earthed, and the exposed conductive parts of the installation are connected to this ground point via a protective earth (PE) conductor.
This part outlines the defensive measures required to keep systems and users safe:
: Covers the general characteristics and assessment of installations.
If you are an electrical engineer, a contractor, or a facility manager, there is one set of documents that acts as the "bible" for your profession: . iec 60364.pdf
Restricts leakage currents and mandates isolated power systems (IT systems) to protect vulnerable patients.
is the International Electrotechnical Commission’s international standard series on low‑voltage electrical installations. It provides a comprehensive set of rules for the design, erection, and verification of electrical installations. The rules are intended to provide for the safety of persons (human beings), livestock, and property against dangers and damage that can arise from the intended use of low‑voltage electrical installations, and to ensure the proper functioning of those installations.
Whether this is for a application?
As of 2025, the IEC 60364 series is more comprehensive and forward‑looking than ever. With the new sixth edition of Part 1 addressing energy efficiency, prosumer installations, and periodic verification, the standard continues to evolve alongside the technologies it governs. Whether you are working in Europe (where HD 60364 is mandatory), Japan (via JIS C 60364), Saudi Arabia (under SASO adoption), or any other jurisdiction, understanding and correctly applying IEC 60364 is an essential professional responsibility.
IEC standards are and are not available for free in their entirety. To obtain an official, complete PDF version of any part of the IEC 60364 series, you must purchase it from an authorized standards distributor.
The source and the consumer installation use independent earth electrodes. In a TN system, the source transformer neutral
N (Connected to Neutral) or T (Direct separate connection to Earth). System Type Description Common Application Key Safety Mechanism TN-S
| Feature | IEC 60364 | NEC (National Electrical Code, US) | BS 7671 (UK) | | :--- | :--- | :--- | :--- | | | International benchmark, goal-oriented, focusing on safety principles | Detailed, prescriptive rules, re-issued every three years | Closely follows IEC 60364 structure, with additional UK-specific requirements | | Voltage Levels | 230V/400V typical (Europe) | 120V/240V typical (North America) | 230V/400V | | Testing | Requires loop impedance meter testing prior to energization | No such requirement (as of latest comparisons) | Similar to IEC, with additional testing protocols | | RCD Requirements | Broad requirements for protection against electric shock | Requires GFCIs (ground-fault circuit interrupters) but with different trip thresholds | Mandates 30mA RCDs for all socket outlets intended for general use |
IEC 60364 is a foundational international standard published by the International Electrotechnical Commission (IEC). Titled “Low-voltage electrical installations” , it provides a comprehensive framework for the design, erection, verification, and operation of electrical systems operating at voltages up to 1,000 V AC or 1,500 V DC. Unlike prescriptive national codes, IEC 60364 is a system-oriented standard based on fundamental safety principles. Its adoption, either directly or through national derivatives (e.g., HD 60364 in Europe, BS 7671 in the UK), has significantly improved electrical safety worldwide. The rules are intended to provide for the
More recently, the IEC 60364 series has expanded to include Part 8, which addresses and prosumer electrical installations (installations that both consume and produce energy). Part 8 provides additional requirements, measures, and recommendations for the design, erection, and verification of all types of low‑voltage electrical installations, including local production and storage of energy, to optimize the overall efficient use of electricity.