Overview
IEC 60947-5-4:2002 is an international standard developed by the International Electrotechnical Commission (IEC) focusing on low-voltage switchgear and controlgear, specifically Part 5-4 which deals with control circuit devices and switching elements. This standard defines a method for assessing the performance of low-energy contacts, including special tests designed to evaluate their reliability and functional integrity. The standard applies primarily to separable contacts used in control circuits across two voltage categories:
- Above (and including) 10 V (typically 24 V), where contacts may switch loads with possible electrical erosion, such as programmable controller inputs.
- Below 10 V (typically 5 V), where electrical erosion is negligible, such as contacts in electronic circuits.
IEC 60947-5-4 addresses the critical need for precise testing methodologies for modern electronic and programmable control systems that rely heavily on low-energy contact performance.
Key Topics
Performance Assessment of Low-Energy Contacts
- Provides clear definitions and principles for testing low-energy contacts used in control circuits.
- Focuses on the monitoring and recording of contact behavior during operations to identify performance and failures.
- Establishes functional bases for test equipment and preferred test values to standardize testing.
Special Tests and Conditions
- Describes specialized testing conditions to simulate real-world application environments.
- Covers preconditioning, ambient condition parameters, and particular tests for contacts intended for specific uses like programmable controller inputs.
- Includes sequences of operations and measurement methods critical for reliable contact performance evaluation.
Data Reporting and Failure Criteria
- Details requirements for information to be included in test reports to support transparency and traceability.
- Defines failure criteria and methods for reporting failure rates, enabling manufacturers and users to assess contact durability and reliability objectively.
Scope Limitations
- Does not apply to functional safety contacts, which are covered under IEC 60947-5-1:2016 Annex N.
- Excludes very low energy measurement contacts such as sensors and thermocouple systems.
Applications
IEC 60947-5-4 is essential for industries using low-voltage switchgear and controlgear with control circuits, including but not limited to:
- Industrial automation: Ensures the reliability of programmable logic controller (PLC) inputs and control circuit contacts.
- Electronic control systems: Provides benchmarks for contacts at very low voltage and current levels.
- Manufacturing processes: Helps maintain consistent testing standards for control devices in production environments.
- Electrical equipment design: Guides manufacturers to design low-energy contacts with predictable and reliable performance in control circuits.
By following the testing methodologies, manufacturers, testers, and users can ensure the operational safety and longevity of control circuit contacts used in various low-voltage applications, avoiding unexpected failures and optimizing overall system efficiency.
Related Standards
- IEC 60947-5-1: Low-voltage switchgear and controlgear - Part 5-1: Control circuit devices and switching elements - Electromechanical control circuit devices. This standard complements IEC 60947-5-4 by covering safety and functional aspects for control devices.
- IEC 60068 Series: Environmental testing standards providing general guidance on conditions and procedures relevant for testing electrical equipment like low-energy contacts.
- IEC 60605-6: Equipment reliability testing methods for validating failure rates, supporting the reliability assessment framework in IEC 60947-5-4.
- Applicable national and regional standards may also reference IEC 60947-5-4 for harmonized performance evaluation of low-energy control contacts.
Keywords: IEC 60947-5-4, low-voltage switchgear, controlgear, low-energy contacts, performance assessment, control circuit devices, switching elements, programmable controllers, contact testing, special tests, electrical erosion, low voltage contacts, industrial automation standards