Complete sets of cabinets, electrical wiring, finished distribution boxes, distribution cabinets

The distribution box is not only the shell and circuit breaker, but also the rigorous wiring process. The following is a summary of several common errors in the distribution box wiring, learn it quickly.

Common wiring errors in the distribution box

1. Bending

When laying all the wires, they should be horizontal and vertical, and the distribution box is the same. However, in the wiring of the distribution box, although it is required to be "straight", it also requires that a 90 ° angle is not allowed.

This is because when the bending angle of the wire is greater than 90 °, it will cause damage to the insulation layer of the wire-the most obvious is that the insulation layer is white and discolored. The consequence is to reduce the resistance of the insulation layer, which has a greater impact on insulation and flame retardancy.

The standard approach is to bend all the corners where they need to be bent, while also ensuring that the vertical wires are perpendicular to the horizontal wires.

2. Crossover

There are two situations where crossovers will occur. The first one is not to distinguish between vertical and horizontal wires as mentioned above, let alone ensure that the two are perpendicular. When the wires are arranged in a mess in the distribution box, the wires are bound to be poor. The consequence of this is that the distribution box is cluttered, and once it breaks down, it will be very troublesome to repair.

The other situation is more serious, referring to the intersection of horizontal and vertical incoming and outgoing lines.

In the picture, the outlet of the main switch is bypassed from the left side of the switch and connected to the upper port of the right circuit breaker. In this way, the outgoing line of the main switch and the incoming line of the main switch are bound to be crossed. This has two consequences: ① The incoming line of the main switch will be pressed by the outgoing line, causing the incoming line wiring to be unstable; ② When the main switch is disconnected and the distribution box is repaired, the maintenance personnel may repair the outgoing line of the main switch When touching the live wire, it will cause electric shock.

3. Jumper

There is a situation where the outgoing line and the incoming line cross this distribution box, which belongs to the content of the previous section, so I won't say more. We only look at the outlet of the main switch-there are four sub-switches behind the main switch, but only 2 wires (one for each of the zero-hot wires) are drawn from the outlet terminal of the main switch. So how does it provide power for the next four sub-switches? (The zero line is directly connected to the zero row, we no longer care about it.)

The method is to connect the outgoing wire to the first sub-switch, then draw a line from the incoming terminal of the first sub-switch, and connect it to the second sub-switch ... In this way, the first, second and third split tubes The upper terminal of the port is connected with two wires. This method of taking power from the upper port of the previous circuit breaker is called a "jumper". The jumper connection method was banned by the national standard as early as 2010 for the following reasons.

The hazards of jumpers

The wire inside the box is generally 4 square millimeters or 2.5 square millimeters, 4 square millimeters of wire, and the maximum current carrying capacity is more than 25A (data from "GB / T 4706.1-2005"). A five-hole socket is rated at 10A, and a three-hole socket is rated at 16A. How many sockets will there be in the entire room? Therefore, the current-carrying capacity of 25A is obviously not enough, which will cause the overload of the wire.

The entrance line is generally 6 square millimeters, and the maximum current carrying capacity is above 32A, which can meet the household (therefore requires that the rated current of the home main switch does not exceed 32A).

So, if I replace the wire in the box, it will be replaced with 6 square millimeters? The answer is no! If the wire is too thick, it will squeeze the space in the box and affect the heat dissipation. Household PZ30 boxes require that the wire should not exceed 4 square millimeters.

The correct connection method is that every time there is a branch circuit breaker, a line must be drawn from the lower port of the main switch.

Finally, we summarize the precautions for wiring the distribution box

1. Horizontal and vertical, but no 90 ° bending is allowed;

2. The outgoing line can not cross the incoming line, you can run the line from behind the circuit breaker, if there is not enough space behind, you can leave a 1-pole (18mm) distance between the main switch and the first branch circuit breaker for wiring , Cover a cover plate in this position afterwards;

3. As many branch circuit breakers as possible, lead a few wires from the main switch. If there are too many leads, you should press the nose of the wire and wrap the heat shrink sleeve before connecting it to the lower port of the main switch.