What is the function of protection modules of thr Plug in Relays ?
Whenever an inductive load is de-energised (coil of a relay or of a contactor), an overvoltage appears at its terminals. This voltage peak can reach several thousand volts and a frequency of several MHz.
It is likely to disturb the operation of automation systems which contain electronic devices.
Protection modules are used to reduce the voltage peak on de-energisation and they therefore limit the energy of interference signals to a level that will not disturb surrounding coils and electronic devices.
The function of each of these modules is indicated below :