How to route a cable over a building facade and what requirements need to be considered
Brick, concrete or stone wall
You can lay the cable without corrugation or tray only if its insulation is UV-resistant. But in practice in most cases it is used SIP, which is designed for outdoor installation and is resistant to ultraviolet radiation, or VVGng-LS, the insulation of which is not resistant to ultraviolet radiation.
In the first case, it is possible to lay the cable along the facade of the building, provided that the distance from the cable to the wall is no more than 6 cm (PUE chapter 2.4, p. 2.4.60).
In the second case, the cable is laid in a metal electrical box. If there is no danger of mechanical damage - you can lay the cable in the corrugation of HDPE (black), but is also found on sale corrugation made of UV-resistant PVC (check this item, as ordinary PVC cracked in the sun). You can also use metal hose. Cable brackets and corrugation clips are fastened to the wall with dowels, nails or nail dowels using a construction gun.
The cable fastening step on horizontal sections should not exceed 350 mm, on vertical sections - 500, in places of bending - 100. The cable entry into the building should be placed in a pipe or piece of metal electrical duct (chapter 2.1. PUE Sec. 2.1.58). About how it is carried out cable routing through the wall, we told in a separate article.
The ideal way to install cable lines along the facade is to lay them in previously punched gates, followed by closing with plaster, but due to the high complexity,in practice it is rarely used.
Due to the high degree of combustibility of wood, the norms for laying on a wooden wall are much stricter than for brick or concrete. In this case, the following conditions must be strictly met:
- The cable line must be laid in a non-combustible jacket.
- Entrance into the building through the wall should be equipped with a metal sleeve made of a thick-walled pipe.
As a rule, a branch from the power supply network is carried out by a self-supporting insulated SIP wire, with aluminum conductors. The use of aluminum wiring with a combustible sheath for laying on a wooden facade is prohibited, therefore, before connecting the line to the wooden wall, you must connect to the cable with copper conductors using special tight clamps. When laying a cable of the SIP brand, it is forbidden to place it close to the siding, it should be located at a distance of at least 6 cm from the wall, even if the wire is led into a corrugated pipe or metal hose.
Wiring can be laid in a metal or plastic cable channel. In the absence of a threat of mechanical damage, it is allowed to use a corrugated pipe made of PVC or metal hose. When using corrugations, it is very important that the purchased product is equipped with a fire safety certificate. In accordance with the regulations, the mounting step of the corrugated pipe must comply with the table:
|Corrugated Pipe Diameter mm||Mounting pitch mm||Corrugated Pipe Diameter mm||Mounting pitch mm|
As an input sleeve, it is allowed to use a thick-walled pipe, the wall thickness of which should correspond to the cross section of the conductors:
Facade from siding
This is the most difficult installation method, taking into account the fact that the siding is a combustible material, and also because of its strength properties it is not intended for mounting brackets for fixing cable lines. Special troubles can be avoided if the necessary cable lines are laid along the facade and walls before the start of finishing work, or partial dismantling of siding plates is carried out. However, often, such options are classified as impracticable, so the homeowner has to decide how to conduct wiring for siding and not violate regulatory requirements.
First of all, the question arises of how and how to fix the line. For bricks and concrete, the product for facade fastening type SF 10 is excellent.
SF 10 provides reliable fixation of the wire harness with a diameter of up to 25 mm, at a distance of 10 cm from the surface. If the siding is laid on a tree, it is better to use a half-screw or screw-hook as fasteners.
When laying a SIP brand cable with a combustible sheath on the facade, it is forbidden to place it close to the siding, it should be located at least 6 cm from the wall, even if it is wound into a corrugated pipe or metal hose. This type of fastener meets these mounting conditions.
Cable lines on the facade are laid parallel to the architectural lines of the building, the use of armored products made with a combustible fiber coating is prohibited. Do not mount power and telephone wires in the same bundle, a 25 mm gap must be provided between them. If several wires are mounted in the route, laying should be done with a minimum number of overlaps.
It is worth noting that if you will lay the SIP wire along the facade, then you must maintain the following distances to the building elements, such as:
with horizontal installation:
- above the window, front door - 0.3 m;
- under the balcony, window, cornice - 0.5 m;
- to the ground - 2.5 m;
with vertical installation:
- to the window - 0.5 m;
- to the balcony, entrance door - 1.0 m.
The video below demonstrates how to draw a SIP wire along the wall:
Here, according to this technology, the cable is laid along the facade of the building in accordance with the PUE.Now you know how to safely lay a cable line on wood, brick, concrete and even siding!
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