Diagram TNS: neutral to ground, ground to neutral but via a wire Separated!
We will double it and use the differential DDR 30 mA again
earth to neutral and then simple power supply to the receiver. Note the passage through the DDR
This time the connection of the mass to the neutral takes place until the connection of the neutral to the earth
When I power up, when I produce the cct (short circuit): everything jumps! Cct and DDR!
If I of cct exceeds Ic of the magneto-thermal, it is the velocity which takes precedence between the DDR and it
This is why selectivity must be provided. However, in the majority of cases ...
The leak is not a contact but a resistance, only the DDR triggers then!
The ammeter measures the leakage current to ground: already 7 mA
Towards 21 mA the DDR trips! Well between In / 2 and In (15 to 30 mA)
Here short-circuit point! Magneto-thermal will not jump!
The advantage over the TT scheme is the wire which references the masses (+ efficient than the ground)