A surge wave, also known as a combination wave, is a powerful spike in voltage or current. Surge pulses cause electrical devices to short-circuit or malfunction. Surge generators simulate surge waves, allowing test engineers to determine the immunity of a component or system during EMC testing. Eliminating sources of EMI in product design and achieving EMC compliance are essential to ensuring electrical substations will continue to provide power, even in extreme cases like lightning strikes.
Common causes of surge or combo wave transients include both lightning strikes and electrical switching. A lightning strike, whether it hits an electrical system directly or travels indirectly via wiring, can result in a surge transient. Electrical switching generates transients when connected loads are altered, due to insulation failure, or other miscellaneous faults, and occurs when one load is switched on and the fault causes a surge of energy to travel to other devices.
Surge Wave Test Standards