These severity levels are halved when tested on signal, data, and control lines.
It is doubtful, however, that the IEC 1000-4-4 can be considered to effectively simulate the interference due to a high frequency pulse field.
It may therefore be necessary to provide increased protection for equipment close to these high voltage transients. The most common
protection is provided by distance from source primarily because the field decays in proportion to 1/ d’ in the near field and to 1]d in the far field.
However, if electronic equipment is required within the vicinity of the source, physical protection may be required. This could include buildings surrounding the susceptible equipment (preferably with conducting properties), covering windows with a wire mesh, and