In all types of projects and building constructions, junction boxes are one of the necessary electrical accessories. During construction, electrical wiring is generally pre-buried between the walls. To protect the wiring, the outside of the wire will be covered with the wire tube. And in the junction part of the wire, if there is a relatively long wire or wire tube to turn the corner, it will generally be put on the junction box as a transition, wire tube and junction box connection, wire tube inside the wire in the junction box connected up. The inside of the junction box is therefore equivalent to an intersection point, which organizes the wiring into the junction box and at the same time plays a role in protecting the wires.

On the back of the wall switches plate, most of the walls are also equipped with concealed junction boxes. And considering that wall sockets are the source of electricity in the room, the quality of the switch junction box must not be ignored. The quality of the switch junction box needs to be concerned, for different junction boxes, we can from its appearance, structure, material, and ability to resist pressure several aspects to talk about.

Appearance

Common switch junction box is generally concealed inlaid in the wall, the general installation of such a way required the good wire planning before wall construction. At present, many older houses or longer history has a certain value of the house, which is not suitable for cutting open the wall to reconnect the wire. Then the surface-mounted switch junction box is also increasingly common. In addition to the similar structure and safety requirements with concealed junction boxes, the surface-mounted junction box compared to the traditional concealed models also considers the aesthetic.

First of all, the depth of the junction box should not be too deep, so that consumers do not bump with other furniture in daily use. Secondly, the bottom of the box and the wall contact parts to be flat to avoid the gap being too large after installation, dust or impurity into, affecting the internal wiring. Further junction box shell around the panel needs to be smooth. For production materials, pay attention to distinguish between new materials and back materials. The use of new materials made of PVC junction box shell surface is relatively smooth, touch does not produce a rough feeling, mostly pure white and not mixed with other impurities, and the toughness of this product is very strong, while the price will be relatively higher than other materials will be some. And back materials we generally refer to the secondary processing of materials, is the production of waste material or the use of obsolete material, after re-processing the formation of the material, also called recycled material. This is very common in the industry, as the secondary use can also reduce costs, but the use of back to the production of junction box shell flame retardant, environmental protection is far less than the new material. This is mainly determined by the trade-off between raw material cost and performance.

Basic structure

Considering the actual wiring complex situation of end consumers, or may add the wiring in the future situation, the junction box hole design is very important. Concealed style as far as possible in all directions reserved holes. Surface style hole number to design reasonable. The holes should be easy to remove and leave no traces, and the size of the holes should be compatible with the size of the tubes.

Switch junction boxes as one of the electrical accessories in the building construction, generally need to be installed by professional electricians, but for many simple wiring, or ageing junction box replacement, many consumers will choose to replace by themselves. This has further requirements for the production process of the switch junction box. On the junction box, the two screw holes (highlighted later in the below article) which used to fix the switch panel is need to be more precise, and the screws can be smoothly screwed in. There will be no misalignment, not flush, too small problems, etc., to facilitate easy installation for end consumers.

Material

The common junction box in daily life is roughly metal iron box material and PVC material. Metal junction box, its grounding, fire performance, hardness and so on is more good. And PVC and other materials, its insulation performance is better. According to different environments, choose different materials of the junction box. For the junction box, the material is important is to be flame-retardant and high-temperature resistant. Junction box material must be safe flame retardant material, to avoid internal wiring problems caused by fire. Junction box internal convergence of several wirings, panel switches and sockets in the use of the wiring process will inevitably heat up. According to IEC60670-1 regulations, junction box shell must reach 850 ℃ flame retardant.

In addition to the material of the junction box shell, there are two screw holes for fixing the panel, which require attention to their material and fixing method. As the bottom box of the wall switch socket, during the use of the socket will often plug-in and plug-out. If the junction box screw holes’ quality is not good, fixed screws will be loose, or even fall off, the panel will be disconnected from the junction box. Therefore, the two screw holes must be not easy to fall off, rust-proof and corrosion-proof, and the market generally adopts a colourful zinc plating process for durability.

Compressive resistance

Most of the junction box using pre-buried way in advance concealed in the wall. The wall after a long time may form a certain pressure on the junction box, resulting in deformation of the junction box, and the subsequent switch panel installation mismatch, or long-term use of the switch panel shift situation. So the box shell needs to have some compressive resistance. In addition to the strong and high-quality raw materials used, the structure can also be reinforced to enhance the compressive resistance.

The appearance, structure, material, compressive resistance, etc. are key points to test junction box quality. Junction box as one of the basic electrical accessories in daily life, protects the basic wiring, ensures the safety of electricity use. In the purchase of wall switch socket panel, it must also be together with the purchase. It is simple but also to be worthy of attention.