Wiring b when leakage protector supplies power and lighting load in TN system

Wiring b when leakage protector supplies power and lighting load in TN system

    TN system, that is, the neutral point on the power side is directly grounded.
    In the figure, the TN-C system is a three-phase four-wire system in which the working neutral line N and the protective neutral line PE are combined into a PEN line; the TN-S system neutral line N cannot be connected to the neutral of
other equipment or lines without leakage protectors. Line N is shared and is not allowed to
be connected to the protective neutral line PE, equipment metal shells, wire steel pipes and other metal parts connected to the earth. That is to say,
a system with three phase lines, a general neutral line N and a protective neutral line PE (PE is led separately from the neutral point of the transformer) through the leakage system
is also called a five-wire system.