TN-S system in the transformer neutral point that pe line and n-line neutral point how to take? N line and pe line in the neutral point on the connected, and then ground the same ground? Or that n line from the neutral point out of their own then a pe line then one after another? If the neutral point out of the ground, in the three-phase imbalance when the n-line current?
TN-S way power supply system It is the work of the zero line and dedicated protection line PE strictly separate power supply system, N line and PE line in the transformer working ground once separated, not to re-connect. Called TN-S power supply system.
The TN-S power supply system is characterized as follows.
1) When the system is running normally, there is no current on the dedicated protection line, but there is an unbalanced current on the working zero line. PE line to ground no voltage, so the electrical equipment metal shell connected to zero protection is connected to the dedicated protection line PE, safe and reliable.
2) The working zero line is used only as a single-phase load circuit.
3) Dedicated protection line PE is not allowed to break, but also not allowed to enter the leakage switch.
4) the use of leakage on the trunk protection, the work of the zero line shall not have repeated grounding, and the PE line has repeatedly grounded, but not through the leakage protection, so TN-S system power supply lines can also be installed on the leakage protection.
5) TN-S power supply system is safe and reliable, suitable for industrial and civil construction and other low-voltage power supply system. In the construction work before the "three links and one leveling" (Dentsu, water, road and ground level - must use TN-S way power supply system.
1, this part you can not look at the design rules, the design process is just that principle, should go to check the installation Atlas;
2, the transformer is the neutral point leads to two lines, one to the transformer shell, and then the shell is also grounded; another to the indoor low-voltage cabinet; this is a line after the PEN line, conditions can lead two , But mostly cited a, is shared by PE and N;
3, in the low-voltage cabinet, from the transformer zero leads to the line is divided into two, one neutral line N, the other is to protect the ground PE; generally in order to ground and reliable, where the PE to access the cabinet, The distribution cabinet is installed on the ground network, is directly connected with the ground network, so it is equal to repeat the ground;
4, N line is the work line, for single-phase load, that is, to over-current, or single-phase equipment can not work; and PE line is the protection line, there is no current flow, a current, , And this should pay attention.
In the transformer side of the PE line and N line are connected to the transformer shell conductive part.
TN-S for the power neutral point directly grounded electrical equipment exposed conductive part of the zero line through the grounding of the zero protection system, N for the work of the zero line, PE for the protection of the ground wire, that is, equipment connected to the PE housing.
