Protection of commercial installations from the high-frequency electromagnetic threats of HEMP and IEMI using IEC standards

The International Electrotechnical Commission (IEC) has been working for nearly 20 years preparing standards and other publications dealing with the threat of high-altitude electromagnetic pulse (HEMP) from a high-altitude nuclear detonation and the threat of intentional electromagnetic interference (IEMI) produced by electromagnetic weapons used by criminals or terrorists. In addition to establishing the electromagnetic environments for each threat, the IEC has also developed generalized protection and test methods to be used for commercial installations. This paper examines the specific problem of a hypothetical commercial building with external power and communications entering the building; in addition the building is assumed to contain a computer server room that is crucial to the operation of the business. The paper applies the IEC standards for these two threats to illustrate how one could design protection for the building and how one would test to ensure that the protection is adequate.