BS EN IEC 60071-2:2018

What is BS EN IEC 60071-2 - Insulation co-ordination about? 

BS EN IEC 60071 is an international standard that discusses insulation co-ordination. The main objective of the BS EN IEC 60071-1 series is to ensure insulation systems offer the required levels of quality and performance. 

BS EN IEC 60071-2 is the second part of multi-series that constitutes application guidelines and deals with the selection of insulation levels of equipment or installations for three-phase electrical systems. It aims to give guidance for the determination of the rated withstand voltages for ranges I and II of IEC 60071-1 and to justify the association of these rated values with the standardized highest voltages for equipment. 

BS EN IEC 60071-2 covers three-phase systems with nominal voltages above 1 kV. The values derived or proposed herein are generally applicable only to such systems. However, the concepts presented are also valid for two-phase or single-phase systems. 

BS EN IEC 60071-2 covers phase-to-earth, phase-to-phase and longitudinal insulation. 

Who is BS EN IEC 60071-2 - Insulation co-ordination for? 

BS EN IEC 60071-2 on insulation co-ordination is relevant to: 

• Power management and energy distribution companies 
• Electric and electronic component and equipment manufacturer 
• Companies involved with earthing, overload and lightening protection systems 
• Electrical engineers 

Why should you use BS EN IEC 60071-2 - Insulation co-ordination? 

Insulation co-ordination is the technique used to ensure that the electrical strengths of the various items of a plant making up the transmission and distribution system and their associated protective devices are correlated to match the system characteristics and expected range of voltages. 

BS EN IEC 60071-2 provides performance, determination of the limit distance, voltages temperature, and testing guidelines. 

BS EN IEC 60071-2 discusses origin and classification of voltage stresses, characteristics of overvoltage protection devices and representative voltages and overvoltages.  

Adopting BS EN IEC 60071-2-compliant application guidelines can help ensure high-voltage installations impart the required level of electrical insulation and dielectric strength, and prevent breakdown and overvoltage, thereby maintaining overall system integrity.  

What’s changed since the last update? 

BS EN IEC 60071-2:2018 is the fourth edition replaces the third edition published in 1996. 

This edition includes the following significant technical changes with respect to the previous edition: 

• The annex on clearance in the air to assure a specified impulse withstand voltage installation is deleted because the annex in IEC 60071-1 is overlapped 
• 4.2 and 4.3 on surge arresters are updated 
• 4.3.5 on very-fast-front overvoltage is revised. Annex J on insulation co-ordination for very-fast-front 
• Overvoltage in UHV substations is added 
• Annex H on atmospheric correction – altitude correction is added.