Electronic devices can be subjected to sudden current and/or voltage increases, referred to as surges. A device’s ability to withstand these surges is referred to as surge immunity, and it’s an important factor in electromagnetic compatibility (EMC).
Surge immunity testing is a form of laboratory testing that assesses your device’s ability to work safely and normally when it’s exposed to an electrical surge.
This guide provides an overview of what surge immunity testing is, how the surge immunity test process works, and steps that you can take to improve your device’s surge immunity.
To talk to us about surge immunity testing or other aspects of EMC compliance, or to request a free quote for testing and certifying your device, contact us online or call us at 866-540-5287.
What is Surge Immunity Testing?
Surge immunity testing evaluates how well an electronic device can withstand electrical surges without malfunctioning or suffering damage.
Electrical surges can occur as a result of power grid fluctuations or switching operations within an electrical system. Certain natural events, such as lightning strikes, can also trigger electrical surges.
Surges introduce high-voltage spikes into the power supply, which may damage or disrupt the operations of electronic devices.
IEC/EN 61000-4-5 Surge Immunity Standard
The most common standard for surge immunity is IEC 61000-4-5. This standard, produced by the International Electrotechnical Commission, provides testing methods and limits for devices subjected to electrical surges.
Compliance with IEC 61000-4-5 (and its EN equivalent, EN 61000-4-5) is required for the EU Electromagnetic Compatibility Directive.
Devices that comply with IEC 61000-4-5 are considered surge immune and typically enter the market in regions that require compliance with surge immunity standards.
Surge Immunity Testing Process
Surge immunity testing involves several steps:
- Device preparation. The device under test (DUT) is prepared under the guidelines of IEC 61000-4-5. The DUT is set up in its operational mode and connected to all testing equipment.
- Testing equipment setup. Testing equipment is set up in the testing environment. This testing involves the use of an electrical surge generator, which is connected to the DUT and provides surge pulses according to the standard’s specifications.
- Testing. Surge pulses are applied to the DUT at various levels, starting from the lowest and gradually increasing to the highest under the standard. The DUT is monitored as it undergoes testing to identify any malfunctions, interruptions or damage.
- Assessment. Following each surge pulse, the DUT is assessed to determine if it can operate normally, or if issues have occurred. The DUT is rated based on its immunity performance during the test.
- Reporting. After testing, a detailed report is prepared outlining test conditions and the performance of the DUT. This report demonstrates compliance with IEC 61000-4-5 for the device and, if appropriate, identifies potential weaknesses in its design.
Surge immunity testing is often performed as part of a range of tests for a specific regulatory directive or standard, such as testing for CE compliance.
How to Improve Surge Immunity for Your Device
Devices can fail surge immunity testing for a number of reasons. Common causes of immunity testing failure include poor selection of components, design issues such as poor PCB layout or grounding, and insufficient surge protection.
In the event that your device fails surge immunity testing, you will likely need to make changes to its design and/or components before retesting your device.
Common methods for improving surge immunity include:
- Implementing proper grounding and shielding
- Using surge protective devices (SPDs) in your device
- Making changes to your device’s circuit board design
- Selecting components with a higher voltage tolerance
- Retesting your device during design and development
If your electronic device has failed surge immunity testing, or if you are unsure about its surge immunity and want to talk to an expert, you can contact us to talk to our engineering team and get answers to your questions.
We offer a range of electromagnetic compatibility consulting services to help you improve your device’s EMC performance and pass testing.
Contact Us About EMC Testing & Certification
As an ANSI-accredited electronics testing laboratory and FCC-recognized Telecommunications Certification Body (TCB), we offer a complete range of EMC testing and regulatory certification services for electronic devices.
To request a free quote for testing and certifying your device, or to ask our engineers a question about electromagnetic compatibility testing and compliance, contact us online or call us at 866-540-5287.
