Signalling on low-voltage electrical installations in the frequency range 3 kHz to 148,5 kHz - Part 4-4: Low voltage decoupling filter - Impedance filter
This standard applies to impedance filters in a mains communication system for phase to neutral voltage not exceeding 250 V a.c. and a nominal current not exceeding 125 A, intended for household and similar fixed installation including residential, commercial and light industrial buildings. This standard also applies to ""plug-in filters"". These filters (see Figure 1) are used to set a suitable impedance, in the nominal frequency range of the mains signalling system, at any point of the low voltage mains network where a low impedance equipment is connected, in order to allow reliable operation of mains signalling system. These impedance filters can be used