In practice, mains power supply networks are susceptible to transients and do not correspond to the clean sinus wave pattern they should theoretically display. Such irregularities in mains power can, for instance, be caused by connecting large inductive or capacitive loads. Voltage spikes, in particular, pose a particular challenge for control gear.
To ensure drivers can meet these requirements, they must be designed in accordance with IEC 61547 "Equipment for general lighting purposes – EMC immunity requirements". The standard specifies requirements for the electromagnetic immunity of lighting systems. The provisions of this standard are based on the requirements for residential, commercial and industrial environments as well as small enterprises, as set out in IEC 61000-6-1, but adapted to suit real-life conditions for operating lighting technology.
In line with EN 61547, drivers are tested with a test voltage of 1 kV between the conductor and earth conductor for inputs ≤ 25 W and 2 kV for inputs > 25 W. However, manufacturers of high-quality products normally conduct such tests with higher voltages. The requirements for outdoor applications are much more stringent, demanding test voltages of 2–8 kV between the conductor and earth conductor, depending on the respective manufacturer's classification.