Masters! ! What about the distribution system?

Installed capacity of 308KW；; Calculating current 275A；; Incoming cable yjv-4 *150; Buried protective flame retardant PVC 200

2. Input disconnector 400A；; Main incoming circuit breaker 315a; ; The main incoming line is equipped with a set of current transformer with a transformation ratio of 350/5, an ammeter and a voltmeter (the line voltage is switched by LW 12 changeover switch).

3. The main bus of this box is a 40*4 hard copper bus, and the L 1, L2, L3 and N lines are the same.

4. This box is equipped with surge protector (including circuit breaker), but the model of surge device is not clear.

5. The outgoing loops are all three phases, which are 1, 2, 3, 4 and 5 floors respectively, and each floor is provided with 2 distribution boxes. The outlet specifications are the same as those of cable VV-4*35+ 1* 16, and the protection mode is SC50 (thick-walled steel pipe), which is buried; The outgoing circuit of 1 1 is VV-5*6 SC25, and the meaning of MTX is unknown.

6. The total box PE is grounded (connected to the total equipotential box MEB, and the total equipotential box grounding resistance is not greater than 1 ohm).

In the drawing, the incoming cable is 4-core, the power supply may be TN-C system, and the outgoing cable is 5-core TN-S grounding system.

From this analysis, the original intention of marking PE on the grounding point in the figure should be to ground the PEN line on the incoming line side (TN-C to TN-S).

Lack of PE bus bars required for outgoing lines (there are only 4 buses mentioned above, but 5-core outgoing lines definitely separate PE from N, and PE lines need 1 bus bar).

(The above is the main intention expressed in this picture.)