Assembly switchboard begins with checking the incoming voltage and integrity of the insulation of the supply cable coming from the common house riser or input circuit breaker. Incorrect switching at this stage can lead to a short circuit or failure of expensive household appliances immediately after power is applied. Before starting work, you must make sure that the input cable corresponds to the rated load and has a sufficient core cross-section for the selected rating input circuit breaker.
The installation process requires strict adherence to the sequence of actions, since errors in phasing or selection of the type of protective automation create a direct threat to the safety of residents. Critical Understand the difference between overload protection and electric shock protection, as these functions are performed by different devices. A well-designed circuit avoids false shutdowns and ensures selectivity of the operation of protective devices throughout the apartment.
Circuit development and selection of components
Design begins with dividing consumers into separate groups, each of which must have its own protection. For rosette lines in living rooms, separate circuits are usually allocated, and for powerful appliances, such as a hob or oven, individual connections are provided. Usage differential protection (RCD) is a mandatory requirement of modern standards for wet rooms and socket groups.
Equipment selection is based on rated currents and tripping characteristics. Circuit breakers must have a “C” characteristic for household networks, which provides protection against overloads and short circuits. Rated current The machine is selected strictly according to the cross-section of the cable, and not according to the power of the connected device, so that the wiring does not overheat.
When choosing RCD The total leakage current of all connected devices should be taken into account. For bathrooms and kitchens where there is a high risk of water intrusion, installing devices with a leakage current of 10 mA is a reasonable precaution. In other cases, the standard 30 mA is sufficient.
⚠️ Attention: It is prohibited to install one RCD for the entire apartment, since if there is a current leak in one device, the entire home will be de-energized, which will create a dangerous situation in the dark.
Preparing the chassis and installing DIN rails
Installation of the panel body is carried out after laying all cable routes, but before finishing the walls, if the panel is built-in. The niche must be prepared taking into account the thickness of the door and the room for cable bending. Cable entry is carried out through standard holes using seals or plugs that provide protection from dust.
DIN rails are mounted inside the case, on which modular equipment will be installed. The distance between the slats should ensure free supply of wires and air circulation. For quality assembly it is important to use comb tires, which allow you to connect machines without unnecessary twists and clutter of wires.
Use soft copper wire PV-3 to assemble the shield, as it is more flexible and easier to install than a rigid single-wire cable.
The DIN rail mounting must be rigid so that the structure does not bend under the weight of the modular devices. Before installing the machines, it is recommended to number their installation locations according to the developed diagram. This will simplify further switching and maintenance of the system.
Installation of modular equipment
Modular devices are installed on a DIN rail using a special locking mechanism. Always installed first introductory machine or a switch that allows you to completely de-energize the switchboard for work. Next, residual current devices and circuit breakers of group lines are installed.
When installing voltage relay It is necessary to observe the connection polarity indicated on the device body. This protection element will save equipment from power surges in the general network. The distance between machines is adjusted using limiters or intermodule switches.
| Device | Function | Installation location | Denomination |
|---|---|---|---|
| Introductory machine | Input protection | Top row | According to the project |
| RCD | Leakage protection | After entering | 30 mA / 40 A |
| Automatic 16A | Rosette group | Group row | 16 A |
| Automatic 10A | Lighting | Group row | 10 A |
The installation density of modules affects the thermal operating conditions of the equipment. You should not pack the machines too tightly without gaps, especially if the shield is metal and is heated in the sun. Thermal release inside the machine it may work falsely if the case overheats.
Switching and connecting wires
The connection begins with disconnecting the zero and grounding on the corresponding buses. Zero bus for the RCD, it must be isolated from the panel body, while the grounding bus (PE) is attached directly to the metal base. The use of color coding of wires (blue - zero, yellow-green - ground) simplifies troubleshooting.
☑️ Check before applying voltage
Phase wires are connected to the lower or upper terminals of the circuit breakers, depending on the type of busbars used. If applicable comb tire, it is inserted into the comb of the machines, and the tap to the RCD is made with a separate wire. It is important not to confuse the input and output on differential machines.
⚠️ Attention: It is strictly forbidden to combine the working zero (N) and protective ground (PE) after the input device, as this will trigger the RCD and violate safety.
Stripping the insulation must be done with a special tool so as not to damage the cable core. The length of the stripped part should correspond to the depth of the terminal so that there is no exposed metal left outside. Tightening torque There should be enough screws for reliable contact, but not excessive so as not to strip the threads.
Crimping and organization of wires
To ensure reliable contact, stranded wires must be crimped with NShVI lugs. Usage heat shrink tubing at the ends of the wires improves visual perception and protects against accidental contact. Bundles of wires are formed into bundles and secured with plastic ties.
The organization of space inside the shield affects the possibility of its maintenance. The wires must not block access to the terminals or prevent the door from closing. Cable channels inside the shield they help hide the vertical descents of wires to the rails.
How to choose tips
For wires with a cross section of up to 10 mm2, NShVI lugs are used. It is important to select the size of the bushing exactly according to the diameter of the core so that the crimping is of high quality.
Labeling each wire on both sides is a mandatory requirement for professional installation. Stickers or tags must be fade-resistant and contain consumer information. This will save hours of work when troubleshooting in the future.
Testing and commissioning
Before applying voltage, it is necessary to perform a visual inspection of the assembly and check for the absence of short circuits between phase and zero. Continuity of circuits A multimeter allows you to identify switching errors. The insulation resistance is checked with a megohmmeter if there is suspicion of cable damage during installation.
The first switching is carried out without load, the operation of each machine and the RCD is sequentially checked. Pressing a button "Test" on residual current devices should lead to an instantaneous break of the circuit. If the RCD does not operate, it must be replaced.
⚠️ Attention: If you hear a cracking sound or smell a burning smell when you turn on the machine, you must immediately turn off the power to the switchboard and check the connections for poor contact.
High-quality installation of an electrical panel is a guarantee of fire safety and durable operation of all electrical wiring in the apartment.
After successful testing, the shield is sealed (if required under the contract with the energy supply organization) and closed. It is recommended to stick a diagram of the panel indicating the ratings of the machines on the inside of the door. Regular tightening of contacts (once a year) will extend the life of the equipment.
Is it possible to assemble a shield yourself without experience?
Theoretically possible, but lack of knowledge about selectivity and rules PUE may cause fire or electric shock. It is better to entrust the work to professionals.
Which machine should I install to enter the apartment?
The rating of the input circuit breaker is determined by the allocated power and the cross-section of the input cable. Usually this is a two-pole circuit breaker with 25A, 32A or 40A.
Is grounding necessary in an old house?
If the house has a TN-C system (two wires in the riser), separate grounding cannot be done. It is necessary to use two-pole circuit breakers at the input and RCDs for protection.
Why does the RCD trip when the washing machine is turned on?
There may be a current leak to the machine body or damage to the wiring. The reason may also be the total background leakage current of other devices.