Installing a junction box is one of the important items that is necessary when arranging the power supply. In addition, it is very important when laying supply lines from the circuit breaker to the consumer. Mounting a separate line for each consumer is too irrational, and therefore junction boxes or, as they are also called, junction boxes are used.
What is a junction box
In this case, it can be argued that the installation of a junction box is the installation of an electrical product that has a closed case. The main requirement for the housing is that it must be made of metal or other dielectric material. Naturally, in this case, the second version of the material for installation is much more preferable, but on condition that it meets the basic requirements of fire safety. The case must be made not only of a dielectric,but still be non-combustible or, as a minimum requirement, not support combustion.
After installing the junction box, or rather its body, power and supply wires are laid inside for consumers or any switching devices. The main task of the box body is to ensure the protection of these cables from dust, moisture, dirt and other foreign things. In addition, it also performs the function of protection against accidental contact with bare sections of a running circuit.
Types of boxes by material
Today, the most common materials are metal and plastic. Installing junction boxes makes wiring easier.
As for metal boxes, they are intended for installation in rooms that are made of combustible materials, such as plastic or wood. Installation of a metal case is also required if the wall is insulated with combustible building material. Inside such boxes, an additional layer of dielectric is usually laid to minimize the chance of accidental contact closure.
If we talk about installing plastic junction boxes, they are more common due to the fact that plastic is cheaper than metal. There are two types of plastic boxes. Some products are made entirely from non-combustible materials (for use in high fire risk environments), while others can be made from simple non-combustible raw materials.
In other words, installing junction boxes in drywall, for example, should in no case be the root cause of a fire when shorting the wiring inside the case.
Inner boxes
In order to successfully carry out an independent installation, you need to know which boxes exist and where they are best used.
The first type of boxes is designed for indoor installation. As the name suggests, they are designed to be installed inside walls or cladding. They usually consist of two main parts. The first is a box, which must be firmly fixed in the supporting structure, that is, in the wall. The second part is a flat cover with which this object will be closed. The cover itself should remain on the surface and be removable so that at the right time there is always free access to the wires. A distinctive feature of such cases is that they have rather thin walls, since they do not carry any structural load.
If the installation is carried out in a solid wall of solid material, then it is best to take the case of a round shape, since it will be much easier to install it. But when installing in drywall, you can use a rectangular box, since the material is easy to process and you can cut a hole of any shape from it.
Outer cases
There is an option to install an external leaky case. As for the conditions of use, it can only be used in cabinets or enclosed spaces. In this casethe body will be protected from the external environment, as well as the power elements of the structure. For these two reasons, the wall thickness should be thicker and the material stronger.
Outdoor products
If the first two types were suitable only for indoor installation, then the third option is suitable for those who decide to install the box outdoors. Mounting the box outdoors implies exposure to natural factors such as rain, fog, freezing, etc. Since all these factors have in common that they create moisture that can conduct electricity, outdoor types of boxes must be airtight. To do this, a special rubber seal is laid between the lid and the body, which prevents water from entering inside. In this case, the wires are inserted inside with the help of crimp (collet) clamps.
However, it is worth adding here that the estimate for the installation of junction boxes will be more expensive than for the installation of conventional ones if the installation is done by specialists.
DIY Installation
Since in this case the main goal during installation is to save money, it will be important to do all the work yourself. To do this, you need to know the installation sequence. Before starting work, it is necessary to carry out a thorough calculation and markup. In addition, there are two ways to distribute the load.
The first is called interior. In this case, an introductory box will be mounted in each room. From the original, or base points will bea power line is laid to each box separately. In addition, each line must be connected to a separate machine. Since powerful electrical equipment can be installed in some rooms, for example, boilers, heaters, etc., it will also be necessary to draw a line of separate power outlets.
The second option provides for installation on different types of consumers. In other words, there will be one box for lighting rooms, and another for TV, table lamps and other things, and a third box for connecting power equipment.
After this stage, you can start rough work: directly to the installation of boxes and laying cables.
Hidden installation
Installing hidden junction boxes means mounting them directly into the wall. To lay the cable, you need to ditch the walls, and drill a hole for the body, and then fix it with alabaster. Pre-prepared wires are removed from the box for disconnection. The length of the free ends that remained in the box should be such that a connection without interference is ensured, and there is also a margin for 2-3 alterations (with cutting off the applied conductors).
As for the connection method, it doesn't matter. The only difference is that the flush-mounted boxes have pre-marked holes for the cable to pass through. There is no need to create tightness here, since there will be only a wall and plaster around, and alabaster brought to a creamy consistency will fill all the cracks, grooves andother.
Open installation type
In this case, we can immediately say that with the open installation of the junction box, the principle of wiring connection remains the same as it was with the closed installation method. Only the installation itself will differ.
Consider installing an open junction box with flexible cable entry. The first thing to do is to install the junction boxes, and after that you can begin to bring external cables to them. Since in this case the case provides protection against dust, moisture and other things, the wires must be inserted into it using sealing clamps. It is worth adding that the wires must be color-coded. If this is a single-phase network, then this is zero, phase and protective ground. A great option would be to hang small tags on the wires to know their purpose. This will help the master not to make a mistake, they are left until all the ends are connected to each other. After the complete installation is carried out, you can transfer the marking to the diagram, and remove the tags from the wires.
