Notice: This information is a brief, elementary overview for someone looking to perform precompliance EFT testing in effort to pass EN/IEC 61000-4-4. The EMC Shop supports many customers to setup and test EFT immunity per IEC 61000-4-4. For in depth analysis of the test standard it needs to be purchased. EFT test equipment manuals usually have key exerpts from the standard.
Electrical Fast Transient Burst (EFT) is the phenomena that occurs when you when you switch off the inductive load. The occurrence of EFT is impossible to predict, so the best method is to take as much preventative measures to prevent damage or malfunction when it does occur. Enter IEC 61000-4-4, the most commonly called out compliance standard for testing robustness and certifying commercial electronics. IEC 61000-4-4 is one of a handful EMC test standards that are required to attain a CE Mark. Below is a brief overview of the test levels performed when conforming to IEC 61000-4-4, for the detailed document you'll have to purchase it at the IEC website. Visit the Test Set-up and Waveform Verification pages for a general overview of EFT testing, the information should be sufficient for verifying your product before sending it to the test lab (pre-compliance).
Be sure the generator and external coupling devices are well grounded. Start testing at lower voltage levels to observe how your DUT responds as well as surrounding equipment in your test area. Your test setup may require you to move equipment and/or isolate your test area a bit more.