Installation of electricians in the garage with their own hands: from the project to the socket

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Constant knocking out of the input machine when the welding machine is turned on or dim glow of lamps during the compressor operation indicates critical errors in the calculation of the cable cross section or the quality of contacts. Electrical network garage is not just a socket for charging the phone, and a complex system that requires taking into account the starting currents of powerful equipment and compliance with strict fire safety standards. Errors in the design or installation phase, such as corrugated twists or lack of grounding, can lead to short circuit, wiring fire, or failure of expensive car electronics.

Before you start cutting walls or laying cables through the air, you need to accurately determine the energy consumption of all future appliances. The total power of lighting, heating devices, chargers for battery and welding inverter dictates the choice of the denomination of the input machine and the cross section of conductive veins. Ignoring this stage often leads to overheating of the wiring and melting of the insulation, which is unacceptable in a garage where combustible materials are stored.

Design of the scheme and calculation of power

The beginning of any electrical installation work is the creation of a detailed wiring, which marked the installation of outlets, switches and lighting fixtures. The garage is characterized by zoning: a work area at the workbench, an observation pit, a parking area and a place for storing the tool. Each zone requires its own approach to lighting and the number of outlets, which allows you to evenly distribute the load over phases and minimize voltage losses.

When calculating the cable cross-section, it is necessary to take into account the material of the vein: copper or aluminum. Copper wires have better conductivity and a smaller diameter at the same load, but they are more expensive. Aluminum cables require more cross-section and are prone to oxidation at the joint sites, which requires the use of special terminals or lubricants. For the modern garage-electric The standard is the copper cable brand VWGng-LSIt does not burn and has a low smoke emission.

Cable cross-section formula

For a single-phase network (220V), the current is calculated by the formula I = P / (U × cos φ), where P is power, U is voltage, cos φ is power factor (usually 0.95). The resulting current is compared with the table of permissible current loads for selecting a cross section.

Particular attention should be paid to the grouping of consumers. The rosette group, lighting and power equipment (for example, machines or welding) is better to be divided into separate lines with individual protection. This will allow you to avoid the entire garage if a fault occurs in one chain, and also simplify the search and troubleshooting in the future.

• 🔌 Rosetta Group3x2.5 mm2 cable, 16A or 20A automatic for powerful consumers.
• 💡 Lighting: cable 3x1.5 mm2, automatic 10A.
• 🔥 Power line (for welding / machine tools): cable 3x4 mm2 or 3x6 mm2, automatic 25A-32A.
• ❄️ Heating/Ventiling: separate line taking into account starting currents.

Selection of materials and components

The quality of electrical installation depends on the materials used. The cable should have a solid vein (monolith), and not a multiwire structure, if it is laid stationary in walls or cable channels. Multiwire wires (PVCs) are designed for movable connections and require mandatory pinheading before being connected to machines, which is often ignored by amateurs.

To protect the network, modular automation is used, installed in the switchboard. The main elements are automatic switches, protecting against overload and short circuit, and protective shutdown devices (CCD) or differential automatics. URCD is necessary to protect a person from electric shock, especially in a garage where high humidity or the presence of conductive floors is possible.

⚠️ Attention: It is strictly prohibited to use homemade fuses (“bugs”) or automatic machines with an inflated denomination. This can cause the wiring to fire long before the protection works.

Cable tracks in garages are often laid in an open way in non-combustible cable-channel Or corrugated pipes. This makes it easier to access wiring for revision and replacement. If metallic corrugation is used, it must be grounded. Plastic corrugated must have a fire safety certificate and not support combustion.

Installation of the switchboard

The heart of garage electrics is switchboard (GROWN) It is placed in an accessible place, protected from mechanical damage and moisture. Inside the shield is mounted DIN-rail, which is attached to the machines, RCD, voltage relay and electricity meter. The shield should be assembled by wire stamp BUGS (flexible) PV-1 (Strict) the appropriate section.

The introductory machine is installed first and turns off the voltage in the entire garage. After it, a counter is usually mounted, then a general RCD (if it is not differentiated) and then branching into group machines. All connections inside the shield must be made reliably, using comb tires for automatic machines or high-quality jumpers from the wire.

Component	Appointment	Recommended denomination	Note
Introductory machine	Protection of input and counter	25A - 40A	Characteristics C
CCD	Protection against current leakage	30 m.	Current above the machine's face value
Lighting machine	Protection of light lines	6A - 10A	Characteristics B or C
Socket machine	Protection of the rosette group	16.	Cable 2.5 mm2

When assembling a shield, it is important to observe the color marking of the wires: phase (L) is white, brown or black; zero (N) is blue; grounding (PE) is yellow-green. Color mixing can lead to serious consequences when repairing a network in the future. All wires inside the shield should be laid neatly, formed into bundles and, if necessary, tightened by clamps.

Laying of cable routes and installation of sockets

Laying cable in the garage has its own characteristics due to the presence of an observation pit and possible storage of fuel. In the observation pit and cellar, it is forbidden to place sockets and switches, as well as laying unprotected cable. The illumination in the pit must be made from a safe voltage (12V or 36V) through a step-down transformer installed outside the pit.

The sockets in the working area are recommended to be installed at a height of 0.8-1.0 meters from the floor to prevent water from entering them when washing the floors or accidental flooding. For the garage, the optimal use of outlets with a high degree of protection IP44 And a ceramic base that better withstands sparkling. Light switches are located at the entrance and in convenient places for local light control.

⚠️ Attention: In garages where it is possible to form explosive vapours (gasoline, solvents), electrical equipment must have an appropriate explosion-proof design. Ordinary household outlets can become a source of spark.

Cable lines are laid strictly vertically or horizontally, avoiding diagonals. The turns of the track are performed at right angles. If the cable passes through metal structures or walls, the passageways are necessarily sleeved with non-combustible materials to protect the insulation from rubbing. Mounting the cable in corrugated is carried out by special clips or clamps with dowel-nails.

Grounding and safety

Availability of contour grounding In the garage, this is not a recommendation, but a requirement for safety. The housings of the shield, sockets and power tools must be securely connected to the grounding bus. Garage cooperatives often use a TN-C system where the ground conductor is combined with zero, which is dangerous. In this case, it is necessary to organize your own grounding circuit or use a high-sensitivity ultrasound.

To create the simplest grounding circuit near the garage, metal corners or pins are driven, which are connected with each other by a steel strip. The resistance to the flow of current of such a circuit should not exceed 4 ohms. It is better to entrust resistance checks to specialists with the appropriate equipment, but visual control of the chain integrity is available to each owner.

• ⚡ ZeroingIn TN-C-S systems, caution and understanding of processes are required.
• 🛡️ CCD: a mandatory element of protection in "raw" garages.
• 🔌 Europlate: have a contact for grounding, unlike the old Soviet ones.

Frequent errors and their consequences

Self-installation of electricians is often accompanied by typical errors that can be costly. One of the most common is the connection of copper and aluminum wires with a twist. The galvanic vapor of these metals is rapidly oxidized, the contact is heated, the insulation melts, and a short circuit occurs. To connect heterogeneous metals, use only terminals.

Another mistake is saving on the cable section "to light up". With a long load, the thin cable operates in the heater mode, losing energy and creating a fire hazard situation. Also often forget about the power reserve: bought today low-power compressor tomorrow can be replaced by a more powerful, and the wiring will not be ready for new currents.

⚠️ Attention: Do not hide the junction boxes under a layer of plaster or skin without access. All connections should be available for inspection and tightening of contacts.

Using cheap, uncertified machines and outlets is a direct way to problems. Cheap plastic when heated can catch fire, and contacts can not withstand the declared current. Choose products from well-known brands, such as ABB, Legrand, IEK or IEK (budget segment), but beware of fakes.

How do you tell a fake machine?

The original machines have clear markings, high-quality assembly without gaps, weight (copper inside is heavy) and holograms. Counterfeits often have a backlash of a lever and cheap plastic.

Installation and verification

After the installation is completed, but before the powerful load is connected, it is necessary to conduct a visual inspection of all connections and "vertebrating" the lines with a multimeter. This will help to identify accidental short circuits between phase and zero or earth. Check the tightening of screws in automatic machines and sockets - the weakened contact warms up.

The first connection is better to make without connected consumers. If the introductory machine does not knock out, check the work of the RCD with the "Test" button. Consistently turn on group machines, checking the presence of voltage in the sockets and the operation of switches. With a voltage indicator or multimeter, make sure that the phase and zero are connected correctly in the sockets.

The final stage is marking the circuit in the shield. Each machine must be signed: "Light", "Rosettes", "Welding", "Pits". This will save time and nerves in the future when looking for faults or replacing a light bulb. Save the circuit of electrical wiring in paper and electronic form.

Can I use aluminum wire in the garage?

It can be used, but with limitations. Aluminum is brittle and requires a larger cross section. Connections with copper to do only through the terminals. For new wiring, it is better to choose copper.

What machine to put on a welding inverter?

Depends on the power of the inverter. For most household models (up to 5-6 kW), a 25A automatic characteristic C and a cable with a cross section of 4 mm2 are sufficient.

Do I need a garage in a co-op?

Yes, I will. Even if the co-op has an old network, local grounding will protect you when insulation breaks on the body of the tool or car.

What height of sockets to choose in the garage?

The optimum height is 100-120 cm from the floor. This is above the level of possible puddles and is convenient for connecting the tool on the workbench.

Can I hide the wires in the wall?

Absolutely not. All connections must be in access junctions. The winding in the wall is a fire guarantee in a few years.