What makes voltage sag testing different?
Unlike most other emissions and immunity testing, the test engineer must control and manipulate all of the power flowing into the EUT. For smaller devices such as personal computers, this is not a great challenge. But for larger industrial equipment, perhaps rated at 480 volts 3-phase at 200 amps per phase, with an expected inrush current of 600 amps or more, the test engineer must be prepared for serious performance and safety challenges. Figure 5: The voltage sag test engineer will insert a sag generator between the AC source and the EUT. Often, high currents (200 amps) and high voltages (480 volts 3-phase) must be handled. Certain sag immunity testing software comes with extensive safety checklists. Some of the checklist items are obvious (for example, Who on the test team is trained in CPR? or Where is the closest fire extinguisher?), and some are less obvious (How do we get access to at least two upstream circuit breakers? and Where is the closest trash can?). This kind of testing
