There are two terminals on the small circuit breaker, two terminals in the lower row, no standard N, the upper two terminals, one is connected to the fire line, the other is connected to the N line, and the lower row has two terminals, respectively the switch The outgoing line (hot line, N line), the N line is not allowed to be grounded again.
When the external line is TN-C, the N wire and the PE wire are combined with the same wire, PEN wire. When the outer wire enters, the PEN wire is first grounded repeatedly, and then divided into N wire and PE wire to become the TN-CS system. The N wire cannot be further thereafter. Ground.
What is TN-C PE PEN TN-C-S?
TN-C and TN-C-S are the transformer neutral point lead line (neutral line) and protective grounding configuration.
PE-protective ground wire (known as ground wire)
PEN-protective grounding neutral, N-line and PE-line are the same wire.
GB50052-2009 "Design Rules for Power Supply and Distribution Systems":
2.0.10 TN System TN System
The power system is directly grounded, and the exposed conductive portion of the electrical device is connected to the ground point through a protective wire. According to the configuration of the neutral conductor (N) and the protective conductor (PE), the TN system can be divided into the following three categories:
1 TN-C system
The N and PE lines of the entire system are one;
2 TN-C-S system
The N and PE lines of a part of the line in the system are unified;
3 TN-S system
The N and PE lines of the entire system are separate.