(also referred to as symmetrical interference voltages). Normal-mode interference voltages occur between the conductors of a defined pair of conductors, i.e. in signal circuits, they are directly superimposed on the signal voltage and in supply circuits, they are directly superimposed on the supply voltage. They stress the isolation between the conductors of the conductor pair and may simulate or eliminate wanted signals at the signal inputs of devices and thus lead to malfunctions. Normal-mode interference voltages are caused by conducted or field-related interferences or the conversion of
common-mode interference voltages in systems not balanced to ground.
