Open wiring must be available at all times. But this "openness" must be safe for wiring and look aesthetically pleasing.
Therefore, the wires are placed in special fastening structures, which in turn are fixed to the surfaces of walls, ceilings and even moving doors.
Fasteners of various design are united under the name "cable channels". A common function for all constructs is the protection of wires from mechanical damage.
Cable ducts for wiring are conventionally divided into the following types and types:
- flexible: chain-like, sectional, tubular;
- rigid: open boxes, boxes with a removable top cover, hollow skirting boards.
Materials for cable ducts must meet several requirements: high strength, elasticity, non-combustibility. An additional plus if the material is electrically insulating.
Therefore, metal (galvanized iron, aluminum) and non-combustible plastics (PVC with additives - hardeners) are used for the manufacture of cable channels.
Rigid case
The box-type cable duct is a straight metal or plastic box.
The following types of rigid cable channels for electrical wiring are produced:
- a box with holes in the walls and bottom, without a top cover;
- box with blank walls and a bottom, without a top cover;
- box with removable snap-on lid and blank walls.
Metal cable channels (without covers) are used in the installation of electrical wiring hidden inside the frame structures: in suspended ceilings, internal partitions, raised floors.
The convenience of such boxes is in the ease of fastening: the cable channel is screwed to the supporting structures with self-tapping screws, the wires are laid inside the box and fixed with plastic clamps.
In boxes with profiled slots, the cooling of the wires is more uniform, which has a positive effect on electrical conductivity.
Closing boxes are designed for surface mounting on walls and ceilings. Manufacturers of electrical fittings use self-extinguishing PVC plastic (polyvinyl chloride) in the production of cable ducts for electrical wiring.
Pure PVC is very flexible, but various mineral additives (gypsum, marble) make it hard. The plastic holds the paint well and does not fade for years.
Colored cable ducts for electrical wiring cost almost the same as white ones. But there have appeared technologies for applying drawings to plastic using the "photo print" method. Abstract drawings are more expensive because they are "designer novelties".
Wide cable ducts can have multiple inner walls for individual lines.
Aluminum cable ducts look elegant and expensive on the walls. Such Italian and German delights are not cheaper than the most exclusive "photo prints". Metal boxes have one plus, which plastics are devoid of - isolation from electromagnetic interference and interference.
A separate type of box cable ducts is a hollow plastic skirting board. The box for the wires is attached to the wall, and the cover (which is also a decorative piece "plinth") is fixed and closes the joint between the floor and the wall. The design of the skirting boards is very diverse, including wood-like (the casting imitates the wood pattern).
The ducts are completed with connection elements: transitions from wide cable channels to narrow ones, 90 ° turns, tees, crosses, corners (internal and external), boxes.
The elements are equipped with lids and are connected to the "lengths" so that they seem to be a single whole.
Flexible cable ducts
The need for flexible protection of electrical wiring is dictated by the features of the "relief" of the walls of the house and outbuildings. If there is an unevenness on the wall (seam, slab joint, drop), the height of which exceeds 2 mm, consider that the cable channel will show it “in all its glory”.
In living quarters it is possible and even necessary to level the walls, but in wooden outbuildings such "luxury" can be too expensive. It is for such cases that flexible cable channels for wires have been created.
Types of flexible cable channels:
- "Flexible chains" (or "tracks") are multi-section structures that can bend along their entire length in one plane (up and down). Each "chain" element is connected to adjacent links by a pivot hitch and has a snap-on cover. There are small gaps between the links, which is why the cable ducts are called "semi-closed".
- tubular: flexible cable duct to go to the door;
- cast from soft plastic or synthetic rubber.
Flexible chains are difficult to manufacture, so their cost is quite high. Used in production to connect machine tools. The owner of a private household can use such a cable channel to protect the cable to a drilling or grinding machine ("emery"). Or in the garage. The width of the flexible chains is from 2 to 23.4 cm.
Flexible cable duct for transition to the door consists of a flexible metal hose and two fasteners (attached to the wall and door). "Flexible armor" can bend countless times, provided that there are flexible wires (twisted from thin wire) inside.
Typically, such transitions are used to power electric locks and sensors.
Cable ducts, molded from rubber or soft plastic, can be called "protection against all kinds of damage." Thick enough walls can prevent moisture ingress. In a private house, a molded cable channel can protect the electrical wiring of the bath (except for the steam room).
Dimensions of cable ducts
The dimensions of box-shaped cable channels for electrical wiring vary from 0.7x1 cm (for alarm wires) to 6x10 cm (for cables and thick wires). Wall thickness: mini-channel - 0.7 mm, medium (20-40 mm) - 1.3 mm, main (60-100 mm) - 2.4 mm.
Standard sizes and photos are shown in the table below:
Typically, the cable duct is produced in a length of 2 meters. It is recommended to buy material with a 10% margin for avoiding difficult areas, accidental damage.
Installation of cable channels
Rigid cable ducts are attached to leveled and finished walls. If the walls are covered with gypsum fiber sheets, small screws are used for fastening - self-tapping screws (1.5 cm) with a flat head.
The box begins to be fastened from the point of attachment of the outlet or lamp (the end of the channel cable is joined to the box with a minimum gap). The distance between the attachment points is 0.3-0.5 meters. The ends of the boxes are joined with a small gap (1.5-2 mm), so that when the temperature in the room rises when the plastic expands, it does not warp the structure.
The plastic is soft enough and can be cut well with a fine-toothed saw. Mini-channels can be cut with a sharp knife.
Cable channels are attached to the plastered walls with small dowel-nails (2.5-3.5 cm). Holes for dowel-nails are drilled with a perforator every 0.4-0.5 meters.
The walls may have surface defects (waves), therefore, during installation, you need to fasten the box "without tension", with a little freedom.
A helpful video on how to select and install a cable duct.