Description of the second-level operator in the distribution cabinet

The distribution cabinet is divided into a primary part and a secondary part. The primary part is generally called the primary loop installer, and the secondary part is handed over to the secondary operator.

First, according to the schematic diagram, if it is not in the same position, it should be connected to the terminal. Never connect three wires to one terminal. If you make a mistake, you won't check it like that. You can only check one by one according to the schematic diagram.

1, selection of conductor section

The circuit of power supply (AC 220V) voltage loop is1.5mm2.. 2.5 mm2 for the current loop. General battery 1.5 square millimeter is enough.

2. When wiring, check whether the signals at both ends of the wire correspond to each other, so as to avoid unnecessary errors.

The most important thing is to understand the schematic diagram and wiring diagram.

Second, if you are a novice, you should first review the drawings, sort out your own ideas, and also check whether there are any problems with the drawings. If you don't understand, you can figure it out first, which is conducive to making lines. Then start wiring. The whole wiring process needs to be careful. Of course, if you are an old hand, you don't have to say so much.

Construction personnel should carefully read and be familiar with the secondary line symbols, and check the secondary wiring diagram with the schematic diagram to ensure that the wiring diagram is correct.

Requirements for secondary wiring construction: construction according to the drawing and correct wiring; Wires and electrical components shall be connected by means of bolts, plugs, welding or crimping. Solid and reliable, good connection; The wiring is neat, clear and beautiful; Wire insulation is good, no damage; There should be no wire connector in the cabinet; The circulation number is correct and the handwriting is clear.

The selection of cable core section shall also meet the following requirements:

(1) Current loop: The working level of current transformer should be accurate. At this time, if there is no reliable basis, the maximum short-circuit current can be determined according to the current capacity of the circuit breaker.

(2) Voltage circuit: When all protection devices and safety automatic devices are in operation (considering development, when the load of voltage transformer is the maximum), the cable voltage drop from voltage transformer to protection and automatic device panel should not exceed 3% of the rated voltage.

(3) Operating circuit: Under the maximum load, the voltage drop from the operating bus to the equipment shall not exceed 10% of the rated voltage.

Three, the current transformer secondary winding is not allowed to open. Short circuit is not allowed on the secondary side of voltage transformer.

Before secondary wiring, you should be familiar with the drawings:

1, schematic diagram. (Represents the working principle and interaction of each loop. The drawing quickly shows the connection mode of each component in the secondary circuit, and also shows the connection related to the primary circuit)

2. Unfolding diagram

3. Terminal layout

4. Installation wiring diagram

These are prerequisites to ensure proper wiring.