BS EN IEC 61051-1:2018

What is BS EN IEC 61051‑1 - Varistors about?  

BS EN IEC 61051-1 is the first part of an international standard used for varistors.  

BS EN IEC 61051-1 provides generic specification and is applicable to varistors with symmetrical voltage-current characteristics for use in electronic equipment. BS EN IEC 61051-1 establishes standard terms, inspection procedures and methods of test for use in sectional and detailed specifications for quality assessment or any other purpose.  

Note: Detail specifications can be specifications within the IEC system, another specification system linked to IEC, or specified by the manufacturer or user. The drafting of a complete detail specification by IEC technical committee 40, if required, follows the rules described in Annex A. 

Who is BS EN IEC 61051‑1 - Varistors for? 

BS EN IEC 61051‑1 on Varistors for use in electronic equipment is useful for: 

• Manufacturers of electronic devices 
• Manufacturers of circuit boards 
• Electronic engineers 

Why should you use BS EN IEC 61051‑1 - Varistors?  

Varistors are useful in protecting a circuit from high voltage surges. A varistor is an electronic component which helps in electrical resistance that varies with the applied voltage.  

BS EN IEC 61051-1 is useful in determining the characteristics and parameters of varistors that result in resisting and withstanding the thermal and abnormal overvoltage. By conducting tests and measurements that help in mounting the varistors you can increase  resistance to corrosion clamps which result in achieving good conductive connections.  

With the help of BS EN IEC 61051-1, you can measure the voltage of the varistor and can verify the current pulse. This current pulse is verified by using the rate energy test mentioned in this document. By conducting a visual examination, you can identify the defects or failures that take place in varistors.  

By applying BS EN IEC 61051-1, you can conduct the test and measurement method for varistors. The generic specification of varistors mentioned in BS EN IEC 61051-1 is useful in manufacturing good quality electronic devices.  

What’s changed since the last update?  

BS EN IEC 61051-1:2018 supersedes BS EN 61051-1:2008. BS EN IEC 61051‑1:2018 

includes some technical changes with respect to BS EN 61051-1:2008. These include: 

• General requirements for electrical tests and 7 new test items – clamping voltage, ESD clamping voltage, maximum peak current, rated average dissipation power, rated energy, electrostatic discharge (ESD), robustness of terminations of surface mount varistors – have been added (see 6.5, 6.11, 6.12, 6.13, 6.14, 6.15, 6.16 and 6.17.8); 
• The test items of pulse current, voltage under pulse condition and bump have been deleted from the section of test and measurement procedures 
• Annex A and the contents referring to the test fixture specified in Annex A have been deleted 
• All contents related to silicon carbide varistors have been deleted 
• A new normative annex entitled "Test pulses used in this specification" (Annex B) has been added 
• A new informative annex entitled "Recommended measurement/test methods for characteristics and parameters for application reference" (Annex C) has been added, in which guidelines of measuring/testing characteristics and parameters for application reference including voltage vs. current characteristic, maximum peak current derating characteristic, thermal resistance and abnormal overvoltage withstanding duration have been given.