For the area of broadband PLC systems in the Czech Republic, there was a recommendation EN 50065-1, valid since 1991. The name of this standard is “Signalization in low voltage electrical installations in the frequency range from 3 kHz to 148.5 kHz.” The recommendation specifies particular frequency bands and limits the output voltage, as it is shown in the following figure.
Absolute voltage levels of stress in [dBμ] voltage values in [V] can be read from the figure for the corresponding frequency amplitude limits. However, there are a few more standards for the application of narrowband PLC used worldwide.