10/0.The grounding design of a 4kV substation is an important electrical engineering task. In the multi-power distribution system, especially in the electrical design of civil buildings, we often encounter the way that two transformers are used to set up bus contact switches in the low-voltage distribution cabinet for the main wiring of the substation. This main wiring method is shown in the following figure:
At present, there are ambiguities in the design drawings of some substations in the description of the grounding formula. In order to understand this problem more clearly, we will analyze the main wiring grounding method. According to the Code for Grounding Design of AC Electrical Installations GB T 50065-2011 Clause 71.Article 2 stipulates that the PEN wire drawn from the neutral point of the transformer must be insulated, and only one point in the low-voltage distribution cabinet must be connected to the PE busbar, so as to realize the system grounding. So, why can you only choose a little grounding?This is because, if the PEN wire is grounded at multiple points, stray currents will be generated. Below, we will go through the three grounding methods of the main wiring in detail** stray current generation.
Substation grounding method 1:
Substation grounding method two:
Substation grounding method three:
Summary:
Requirements and specifications for surge protective devices (SPDs) in low-voltage power distribution systems.
What exactly is the IT, TT, TN system in electrical?A ** will take you to understand
Does the fire pump have to be started with a star delta?A lot of people are still in the dark!
How much do you know about the main parameters and tests of SPD surge protective devices?