Modernization of the housing energy system begins with the design of a central power distribution unit. Electric shield in the apartment is the heart of all wiring, and the quality of its assembly depends not only on the stability of household appliances, but also fire safety. Modern energy requirements dictate their own rules: instead of one input machine and meter, a complex protection system is now required.
Property owners often underestimate the importance of a competent layout of equipment inside the box. Errors in the installation phase can lead to frequent power outages or, worse, to the failure of expensive electronics. In this article, we will discuss in detail how to design and assemble a reliable protection system, avoiding common mistakes of beginners.
Main components of the switchboard
The foundation of any assembly is the right equipment. The central element is switch-off, which cuts off the power of the entire apartment in case of critical overloads or short circuit at the entrance. Its nominal value must strictly correspond to the allocated capacity agreed with the energy supply organization.
To protect a person from electric shock and prevent fires due to leaks is used CCD (device of protective shutdown) or differential automatic. These devices compare currents at the input and output, instantly reacting to the slightest discrepancies. Modular automation It is placed on the DIN-rail, providing ease of installation and maintenance.
Do not forget about auxiliary elements such as comb tires and zero terminals. They allow you to create a neat and reliable switching, excluding twists and chaotic bundles of wires. Use quality components from proven brands, such as ABB, Legrand or IEKIt guarantees a long service life of the entire system.
- 🔌 The input machine is the main switch that limits the total power consumption.
- ⚡ UZO or difautomats - provide protection against current leaks and electricity damage.
- 🔧 DIN-rail is a standard profile for mounting modular equipment.
- 📏 Comb tire is a professional way of connecting groups of automatic machines without jumpers.
⚠️ Attention: It is strictly forbidden to save on the input machine and protection devices. Cheap analogues may not work at the right time or, conversely, falsely turn off when the starting currents of powerful devices.
The quality of the shield assembly directly depends on the reliability of each individual component, so the use of certified equipment is a mandatory standard.
Load calculation and selection of machines
Before buying equipment, you need to make a detailed wiring scheme and calculate the current load on each line. Nominal current The circuit breaker is selected based on the cable cross section, not the power of the consumers. This is the basic rule of electrical installation: the automatic machine protects the cable from overheating, not the equipment.
For lighting, 6A or 10A machines are usually used, since modern LED lamps consume minimal energy. The socket groups are powered through modules at 16A, which corresponds to the standard cross-section of a 2.5 mm2 copper wire. For high-power consumers, such as electric stoves or cooking surfaces, separate lines with 25A or 32A machines are required.
It is important to consider the nature of the load. Active consumers (heaters, incandescent lamps) create a constant load, while engines (refrigerators, washing machines) have high starting currents. For such cases, it is recommended to use automatics with a characteristic SThey can withstand short-term overloads without false positives.
| Type of consumer | Cable cross-section (mm2) | Score of the machine (A) | Characteristics |
|---|---|---|---|
| Lighting | 1.5 | 6-10 | B or C |
| Rosettes (general) | 2.5 | 16 | C |
| Air conditioner | 2.5 | 16 | C |
| Cooking panel | 4.0 - 6.0 | 25-32 | C |
Connection schemes and layout
There are two main approaches to the assembly of the shield: the use of separate bundles "Automatic + RCD" and the use of differential machines. The first option is cheaper, but takes up more space in boxing and requires careful grouping calculation. The second option is more compact and easier to diagnose, but much more expensive to implement.
In a group scheme, all machines are divided into several groups, each of which is protected by its own system. CCD. For example, the bathroom, kitchen and sockets of rooms can be divided into different protection contours. This allows you to localize the problem: when the current leaks in the bathroom, the light in the rest of the apartment will not go out.
The interior of the shield should be ergonomic. The introductory machine and the counter (if installed in the apartment) are usually located on the top or left. Consumer lines are grouped logically so that, if necessary, you can quickly find the right switch. Keep a spare space (15-20%) for possible expansion of the functionality.
Why can’t you put one smear on the whole apartment?
If you install one common RCD on all lines, then with the slightest leakage of current in any device (for example, in the refrigerator), electricity will turn off in the entire apartment. In addition, the total natural current leakage of all lines may exceed the trigger threshold (30 mA), which will lead to permanent false shutdowns.
For connecting machines within one group is ideal. comb-tyre. It provides reliable contact and eliminates the risk of poor wire twisting. However, if the number of machines in the group changes, you have to use flexible connectors or make jumpers from a wire.
- 📐 Topology "star" - each machine is powered separately from the common crest.
- 🔗 Serial connection – suitable for small groups with the same load.
- 🛡️ Selectivity: Configuring delays to activate in a phased manner.
Tools and installation process
Quality assembly is impossible without a specialized tool. You will need a set of screwdrivers with different stings, a stripper to clean the insulation without damaging the vein and a dynamometer screwdriver. The latter tool is particularly important as it allows you to tighten contacts with the effort recommended by the manufacturer.
The installation process begins with the installation of DIN-relays and mounting the body box on the wall. The shield should be installed strictly vertically, at a height convenient for maintenance (optimally 1.5-1.7 meters from the floor). After fixing the housing, the modular equipment is placed according to a pre-designed scheme.
☑️ Preparation for installation of the shield
When cutting wires, observe the color code: phase wire is usually brown, white or black, zero - blue, earthing - yellow-green. The ends of the wires are cleaned to a length corresponding to the depth of the contact group of the machine. Excessively long cleaning can lead to the bareness of the current units, which is unacceptable.
⚠️ Attention: Aluminum wires cannot be directly connected to copper contacts of machines without the use of special transition terminals or lubricants, since the aluminum-copper galvanic pair quickly oxidizes, causing heating.
Typical errors in assembly
One of the most common mistakes is connecting wires of different sections in one clamping machine. The thin wire may not be pressed, which will lead to sparking and melting of the insulation. If you need to combine lines, use zero tires or special combs with taps.
Ignoring the labeling of wires and groups also complicates future operation. In a few years, even the master himself may forget which machine is responsible for what. Marking must be applied to each wire at the entrance to the shield and on the front panel of the box under a transparent sticker.
Often there is an incorrect choice of the type of RCD. To protect sockets and lighting in the apartment, devices with a leakage current of 30 mA are enough. Setting more sensitive (10 mA) on common groups will lead to frequent false positives, while less sensitive (100 mA) will not provide adequate protection for the person.
Use special limiters on the DIN-rail to lock the modules and prevent them from moving during vibration or transportation.
Verification and commissioning
After the installation and visual inspection is completed, the system must be tested. First of all, the reliability of tightening of all contacts is checked. Then, with disconnected consumers, the voltage is applied to the input and the presence of a phase at the outputs of the machines is checked.
The performance of protective shutdown devices is necessarily tested. Each RCD or difautomat has a button "Test" (marked with a letter). T). When pressed, the device must instantly turn off the power of the protected line. If this does not happen, the device is defective and must be replaced.
The final step is to check the load. Turn on powerful appliances at the same time and make sure that the introductory machine does not warm and knock out. Check the absence of foreign sounds (buzzing, coding) inside the shield during the first hours of operation.
Regular (once every six months) check of tightening of contacts and testing of button "Test" on the RCD prolongs life of the electric shield and guarantees safety.
Can I build a shield without an electrician?
Theoretically yes, if you have knowledge of electrical engineering and observe safety. However, connecting the inlet cable and sealing the meter often requires a permit from the power company. Mistakes in assembly can cost the burned equipment or fire.
Which shield is better: plastic or metal?
For the apartment, plastic boxes are more often chosen because of the aesthetics and the lack of need to ground the housing itself. Metal shields are stronger and more fire-resistant, but require a reliable grounding of the door and the housing, which is not always possible in older homes.
Should I change the introductory machine when increasing power?
Yes, if the energy supply organization has allocated additional power, it is necessary to replace the input machine with the corresponding nominal value. Just put the machine more powerful can not - burn the wiring to the counter or the cable itself entry into the apartment.
How often do I need to change the switches?
Automata do not have a strict expiration date, but are mechanical devices. The response resource is limited by the number of cycles. If the machine hasn't knocked out and warmed up, it can last for decades. With frequent shutdowns, the resource decreases.