Technical Articles

IEC 60255: Electrical Relays - General Requirements and Test Procedures

Title: A Comprehensive Guide to IEC 60255: Understanding General Requirements and Test Procedures for Electrical Relays




Electrical relays play a critical role in the protection, control, and monitoring of electrical systems, ensuring safe and reliable operation in various applications. The International Electrotechnical Commission (IEC) has developed the IEC 60255 standard, which defines the general requirements and test procedures for electrical relays. In this article, we will explore the details of IEC 60255 and highlight its significance in ensuring the performance and functionality of electrical relays across different industries.


Understanding IEC 60255


IEC 60255 is a comprehensive standard that covers the essential requirements and test procedures for electrical relays used in power systems, industrial automation, and other applications. The standard establishes guidelines for the design, construction, testing, and performance assessment of relays to ensure their reliability, accuracy, and consistency in responding to electrical faults and abnormalities.


One of the primary objectives of IEC 60255 is to ensure that electrical relays meet the specified operating characteristics, such as sensitivity, accuracy, response time, and stability, under various operating conditions. The standard sets forth the parameters and criteria that manufacturers must adhere to when designing and testing relays to guarantee their compliance with industry standards and customer expectations.


General Requirements for Electrical Relays


IEC 60255 defines the general requirements that electrical relays must meet to ensure their proper functioning and performance. These requirements cover a wide range of aspects, including:


1. Operating Principles: The standard outlines the basic operating principles of relays, such as electromagnetic attraction, thermal effects, and solid-state switching, to ensure the reliable operation of relay devices.


2. Environmental Conditions: IEC 60255 specifies the environmental conditions, such as temperature, humidity, and vibration, that relays should be able to withstand to ensure their durability and performance in harsh operating environments.


3. Safety and Reliability: The standard emphasizes the importance of safety and reliability in relay design, addressing factors such as insulation coordination, dielectric strength, and fault tolerance to minimize the risk of malfunctions and safety hazards.


Test Procedures for Electrical Relays


IEC 60255 provides detailed guidelines for conducting various test procedures to assess the performance and functionality of electrical relays. These test procedures cover a wide range of parameters and characteristics, including:


1. Accuracy Tests: The standard specifies methods for testing the accuracy of relays in detecting and responding to electrical faults, ensuring that relays operate within specified tolerances and provide reliable protection.


2. Sensitivity Tests: IEC 60255 outlines procedures for evaluating the sensitivity of relays in detecting low-level electrical signals and triggering appropriate responses, ensuring reliable operation under varying load conditions.


3. Performance Tests: The standard includes test procedures for assessing the overall performance of relays, such as response time, coordination with other protection devices, and stability under dynamic operating conditions.


Significance of Compliance


Compliance with IEC 60255 is essential for manufacturers, system integrators, and end-users to ensure the reliability, safety, and performance of electrical relays in diverse applications. By following the guidelines and test procedures outlined in the standard, stakeholders can verify the quality and functionality of relay devices, identify potential issues or deficiencies, and address them during the design and testing phases.


Furthermore, compliance with IEC 60255 enables seamless integration and interoperability of relay devices from different manufacturers, facilitating the deployment of reliable and efficient protection, control, and monitoring systems in electrical grids, industrial plants, transportation systems, and other critical infrastructure. The standard serves as a benchmark for evaluating the performance of relays and validating their compliance with industry standards and regulatory requirements.




IEC 60255 plays a vital role in defining the general requirements and test procedures for electrical relays, ensuring their reliability, accuracy, and performance in various applications. By adhering to the guidelines outlined in the standard, manufacturers can design and test relay devices that meet the highest standards of quality and functionality, thereby enhancing the reliability and safety of electrical systems. Compliance with IEC 60255 not only demonstrates a manufacturer's commitment to excellence but also fosters trust and confidence in the performance of relay devices among users and stakeholders in the industry.



Contact: Eason Wang

Phone: +86-13751010017


Add: 1F Junfeng Building, Gongle, Xixiang, Baoan District, Shenzhen, Guangdong, China

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