The standard, titled "Power installations exceeding 1 kV AC and 1,5 kV DC – Part 1: AC" , serves as the international benchmark for the design and erection of high-voltage electrical power installations. Published in July 2021, this third edition replaces the 2010 version, introducing critical technical updates to align with modern engineering practices and safety protocols. Core Objectives and Scope
❌ Using 2010 clearances for systems with arresters – 2021 reduces some gaps. ❌ Ignoring Annex B for soil resistivity modeling – leads to unsafe touch voltages. ❌ Applying AC rules to DC installations – that is IEC 61936-2. ❌ Overlooking fire separation between control buildings and HV equipment – clause 9.3 is strict. iec 6193612021 link
Clearance tables (minimum distances between energized parts and earth or public areas) have been harmonized with IEC 60071 (Insulation Co-ordination). This reduces ambiguity during the design phase of substations. 3. Fire Safety and Environmental Protection The standard, titled "Power installations exceeding 1 kV
| Voltage (kV) | Min. phase-to-earth clearance (indoor, standard atmosphere) | |--------------|-------------------------------------------------------------| | 12 | 120 mm | | 24 | 180 mm | | 36 | 250 mm | | 52 | 360 mm | | 145 | 1.0 m (approx.) | ❌ Ignoring Annex B for soil resistivity modeling
The 2021 amendment mandates a risk assessment per . If the risk exceeds tolerable levels, a Lightning Protection System (LPS) Level I or II is required.
IEC 61936-1:2017+AMD1:2021 CSV (Note: This link leads to the official IEC Webstore. The standard costs CHF 345.00 as of 2025.)
Here is the story behind the link and the standard, broken down into the drama of modern power engineering.