Assembly or replacement of the input unit is a critical step in ensuring the power supply of any object, whether it is a residential building, a summer cottage or a garage. Exactly. counter-board It becomes the point of entry of electricity, where its commercial accounting and primary distribution to consumers. From the quality of the assembly, the correctness of the selected equipment and compliance with the installation standards depends not only the durability of the wiring, but also the fire safety of the entire structure.
Many car owners, equipping a garage for parking and car maintenance, are faced with the need to provide a full-fledged electrical network. This is necessary not only for lighting, but also for the operation of compressors, welding machines and chargers. In such conditions, a well-designed supply-board (VRSh) becomes the foundation of stable operation of all equipment.
In this article, we will analyze all the nuances: from the choice of the case to the final voltage test. You'll know what it is. switch-off It is better to use how to connect a single-phase or three-phase meter correctly and why saving on quality fittings can lead to serious consequences.
Criteria for the selection of an electric shield and installation site
The first step is always to determine the type of body. For a garage or outdoor installation, it is critical to use shields with a high degree of protection, marked as IP54 or IP65. Such boxes are equipped with a rubber seal around the perimeter of the door and plugs for the introduction of cables, which reliably protects the internal components from dust, moisture and condensate, which often forms in unheated rooms.
The size of the shield is selected based on the number of modules that need to be placed inside. The standard module has a width of 18 mm (one pole of the machine). For a full-fledged metering node, a place is usually required under the input machine, the meter itself (takes 2-4 modules), the RCD or difautomat, as well as several group automatic machines. Always take a shield with 20-30% free space so that new lines can be added in the future, for example, for a powerful electric vehicle charger.
⚠️ Attention: It is strictly forbidden to install plastic shields in the immediate vicinity of flammable materials or in areas where mechanical damage to the body with tools during maintenance of the car is possible.
When choosing the material of the body, it is necessary to take into account the operating conditions. Metal shields are stronger but corrosion-prone when coatings are damaged, whereas quality non-combustible plastic (ABS) is chemical resistant and dielectric. It is also important to check whether there is an internal DIN-reys and ground and zero tires, which are often included but may be of poor quality.
Set: counters, automatics and protective automation
The heart of the system is the electric meter. For garage needs and private homes, single-tariff or multi-tariff metering devices are most often used. When choosing, pay attention to the rated current; modern models often have markings. 5(60) A or 10(100) AThis means that it can be overloaded for a short time to 60 or 100 amps, respectively. For a garage with welding, it is better to take a model with a stock of current.
The second most important element is modular automation. The introductory machine protects the entire line to the counter and the meter itself from short circuit. The protective disconnection device shall be installed after the counter (CCD) or a differential automatic. They respond to current leakage, protecting a person from electric shock when touching live parts or the body of a faulty tool.
Group machines distribute energy to consumers. A separate line is allocated for outlets, lighting and powerful consumers (compressor, machine tools). The nominal value of the machines is selected strictly by the cable cross section: for a cable of 2.5 mm2 - a 16A automatic, for 1.5 mm2 - 10A. The use of machines of greater denomination than the cable allows is unacceptable, as this will lead to melting of the insulation.
- 🔌 Introductory machine - disconnects the power of the entire shield, is used to maintain and protect the input.
- ⚡ Electricity meter - commercial metering device requiring filling by an energy supplying organization.
- 🛡️ RCD or Difautomat Protection against current leaks to the "ground", saves life when the insulation breaks down.
- 🔦 Group machines protect individual lines of wiring from overload and short circuit.
Connection scheme and procedure for assembling the shield
The installation of the shield begins with the development of the scheme. The classic sequence of elements looks like this: introductory cable → introductory machine → counter → RCD → group machines. This arrangement allows you to de-energize the entire shield for replacing the counter or checking contacts without breaking the seals on the input machine (if it is installed in front of the counter in a separate box, which requires energy sales).
Combine tires are most convenient for connecting modules inside the shield (comb). They provide reliable contact and neat appearance, unlike a bundle of jumpers from wires. The phase wire from the exit of the counter is fed to the comb, which distributes the phase to all machines. Zero bus connects via RCD.
Nuances of connection of three-phase meters
When connecting a three-phase meter, it is important to strictly observe the order of phases (A, B, C) and not confuse them with zero. A phasing error can cause three-phase equipment, such as compressors or machine tools, to fail.
When mounting, follow the color markings of the wires: yellow-green for grounding (PE), blue for zero (N), and any other (usually white, red or black) for phase (L). Inside the shield, the wires must be laid neatly, the beams are tightened with plastic clamps, and tips of the corresponding diameter are installed at the ends.
☑️ Checking before applying voltage
Technical characteristics and comparison of equipment
When selecting components for plug-board It is important to pay attention not only to the brand, but also to technical parameters. Cheap automation of Chinese brands may not work at the right time or, conversely, knock out the engine compressor at the start load. Reliable manufacturers such as ABB, Schneider Electric, Legrand or IEK (in premium lines) guarantee the declared performance.
| Parameter | Introductory machine | Group machine | CCD |
|---|---|---|---|
| Nominal current | 25-50 A | 10-16 A | 25-63 A |
| Disconnection | 6000 A (6kA) | 4500 A (4.5kA) | — |
| Leakage current (for RCD) | — | — | 30 mA (0.03 A) |
| Number of poles | 2 (1P+N) | 1 or 2 | 2 (1P+N) |
Disconnecting power is the maximum short-circuit current that an automaton can break without destroying its body. For garage cooperatives, where the transformer substation can be nearby, the currents of the CZ are high, so the minimum threshold is: 4.5 kAbetter. 6 CA.
Safety rules and typical installation errors
One of the most common mistakes is poor contact at the points of connection of wires. An untied screw on the terminal of the machine leads to heating, burning insulation and eventual fire. After assembling the shield, it is necessary to check the temperature of the machine case and the tightening of the contacts after 15-20 minutes of work under load, since the metal tends to cool down and require a lift.
⚠️ Note: It is forbidden to use zero wire (PEN) inside the consumer shield to ground. The separation of zero and earth should occur strictly up to the meter or in a special input node, if the power supply scheme allows.
Another mistake is the lack of selectivity. If you have an introductory machine on 25A and a group on 25A, then with a short circuit in the socket, the entire garage can be knocked out, not a specific line. It is necessary to observe the hierarchy of denominations: the input machine should always be more powerful than the group.
Use a special contact paste when connecting aluminum and copper wires to prevent oxidation and heating at the twisting or terminal site.
Installation and operation
After assembly. counter-board Visual monitoring and multimeter verification is carried out. It is necessary to ensure that there is no short circuit between phase and zero, and also between phase and earth. The resistance to insulation should be high. Only then can the tension be applied.
The first connection is better to make without connected consumers. Take the machines, check for voltage at the output of the group lines. Press the button. Test On the RCD - it should immediately turn off the power. If the RCD does not work, it must be replaced, as the protection does not work.
During operation, especially in garage conditions with temperature changes and dustiness, it is recommended to carry out prevention once a year: blow the shield with compressed air from dust and check the tightening of screw connections. Dust mixed with moisture can become conductive and cause breakdown.
A high-quality accounting shield assembly is an investment in security. Savings on machines of unknown brands can cost the cost of a burned-out car or garage.
Can I replace the electricity meter myself?
Independent replacement of the meter without notifying the energy supply organization is prohibited and will lead to a fine. You can buy a device and prepare the place, but only a representative of the power company or a licensed electrician with subsequent sealing should tear the seals and connect a new meter.
Which wire is better to use to assemble the shield?
For internal connections in the shield, use only the PV-3 copper wire (PUGV) of the appropriate cross-section. Aluminum wires in shields can not be used because of their brittleness and the property of "leaking" under the screw clip, which leads to a weakening of the contact.
Do I need to get grounded in the garage shield?
Yes, having a ground circuit and connecting it to the PE bus in the shield is essential for safety. This guarantees the operation of the RCD and automatic machines during the breakdown phase on the body of the power tool or car.