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The electrical panel in a private house, in a country house, in an apartment performs a dual function: it provides input and distribution of electricity and creates safe operating conditions. If there is a desire to understand not the simplest issue, you can assemble the electrical panel with your own hands. The introductory machine and the meter should be installed by representatives of the power supply organization, but further, after the meter, you can assemble the circuit yourself (although they do not like to lose money). True, before commissioning the house, you will need to invite them to be present at the start-up, check everything and measure the ground loop. All these are paid services, but they cost much less than a complete shield assembly. If you do everything correctly and according to the norms, it will turn out even better on your own: you are doing it for yourself.
What should be in the box
Both in an apartment and in a private house there are several options for the layout of the shield. This mainly concerns the installation site of the introductory machine and counter. In a private house, they can put a counter on a pole, and a machine gun on the wall of the house, almost under the roof. Sometimes the counter is placed in the house, but this is if it was built a couple of decades ago. Recently, metering devices have been installed extremely rarely in the house, although there are no decrees and instructions on this matter. If the meter is located indoors, it can be placed in a shield, then when choosing a model of the shield, it is necessary to take into account the dimensions of the meter.
How to connect electricity from the pole to the house, read here.
In some apartment buildings, meters are in boxes in the stairwells. In this case, the cabinet is needed only for RCDs and machines. In other houses, he stands in an apartment. When upgrading the electrical network, the cabinet will have to be bought in such a way that the meter fits there too, or buy a separate box for the meter with an introductory machine.
When drawing up a power supply scheme, safety is very important. First of all, it is provided for people: with the help of an RCD – a residual current device (pictured at number 3), which is installed immediately after the meter. This device is triggered if the leakage current exceeds the threshold value (a short circuit to the “ground” occurred or someone put their fingers into the socket). This device breaks the circuit, minimizing the possibility of electric shock. From the RCD, the phase enters the inputs of the automata, which also work when the load is exceeded or when there is a short circuit in the circuit, but each in its own area.
Secondly, it is necessary to ensure the normal operation of household appliances and electrical appliances. Modern sophisticated technology is controlled by microprocessors. They require stable power to function properly. After observing the voltage in our network for some time, you cannot call it stable: it varies from 150-160 V to 280 V. Imported equipment cannot withstand such a spread. Therefore, it is better to turn on at least some groups of machines that supply power to complex equipment through a stabilizer. Yes, it costs a lot. But during power surges, the control boards are the first to “fly”. They are not repaired by us, but simply changed. The cost of such a replacement is about half the cost of the device (more or less depends on the type of device). It’s hardly cheaper. When assembling a switchboard with your own hands, or just planning it for now, remember this.
A stabilizer is installed on one or several groups and is turned on after the RCD and in front of the group machines. Since the device is rather big, it will not be possible to install it in the shield, but please, next to it.
Also, two tires are installed in the shield: grounding and zeroing. All ground wires from instruments and devices are connected to the ground bus. The wire comes to the “zero” bus from the RCD, and is fed to the corresponding inputs of the machines. Zero is usually denoted by the letter N; when wiring, it is customary to use a blue wire. For grounding – white or yellow-green, the phase is led with a red or brown wire.
When assembling the electrical panel yourself, you will need to purchase the cabinet itself, as well as rails (called DIN rails or DIN rails) on which machines, RCDs and switches are attached. When installing the rails, check their horizontal level: there will be no problems with mounting the machines.
All machines must be interconnected. This can be done using conductors – connecting their inputs in series, or using a ready-made connecting comb. A comb is more reliable, although it costs more, but given the time you spend connecting all the machines, it is unlikely that a few tens of rubles are of such fundamental importance.
Scheme for several groups
Power supply schemes are not always simple: consumer groups are divided into floors, outbuildings, lighting of the garage, basement, yard and adjacent territory are taken out separately. With a large number of consumers, in addition to the general RCD after the meter, they put the same devices, only of lower power – for each group. Separately, with the obligatory installation of a personal protective device, the power supply for the bathroom is removed: this is one of the most dangerous rooms in the house and apartment.
It is highly desirable to put protective devices on each of the inputs that go to powerful household appliances (more than 2,5 kW, and even a hair dryer can have such power). Together with a stabilizer, they will create normal conditions for the operation of electronics.
In general, when designing an accurate circuit, you will have to find a compromise: make the system safe and not spend too much money on it. It is better to take equipment from trusted companies, but it costs decently. But the power grid is not an area where you can save.
How to connect an electric hob read here, and how to connect an electric water heater (accumulative or instantaneous) read in this article.
Types and sizes of electrical panels
We will talk about cabinets / drawers for the installation of machines and other electrical stuffing, about their varieties. According to the type of installation, electrical panels are for outdoor installation and for indoor. The box for outdoor installation is attached to the wall with dowels. If the walls are combustible, an insulating material that does not conduct current is laid under it. When mounted, the external electrical panel protrudes about 12-18 cm above the wall surface. This must be taken into account when choosing a place for its installation: for ease of maintenance, the shield is mounted so that all its parts are approximately at eye level. This is convenient when working, but can threaten with injuries (sharp corners) if the place for the cabinet is chosen poorly. The best option is behind the door or closer to the corner: so that there is no possibility of hitting your head.
A flush-mounted shield implies a niche: it is installed and walled up. The door is on the same level with the wall surface, it can – protrude by several millimeters – depends on the installation and design of a particular cabinet.
Cases are metal, painted with powder paint, there are plastic ones. Doors – solid or with transparent plastic inserts. Various sizes – elongated up, wide, square. In principle, for any niche or conditions, you can find a suitable option. One tip: if possible, choose a larger cabinet: it is easier to work in it, this is especially important if you are assembling an electrical panel with your own hands for the first time.
When choosing a building, they often operate with such a concept as the number of seats. This refers to how many single-pole circuit breakers (12 mm thick) can be installed in a given housing. You have a diagram, it shows all the devices. You count them taking into account the fact that two-pole ones have a double width, add about 20% for the development of the network (suddenly buy some other device, but there will be nowhere to connect it, or during installation decide to make two from one group, etc.). And for such a number of “seats” look for a shield that is suitable in geometry.
Installation and connection of elements
All modern machines and RCDs have a unified mount for a standard mounting rail (DIN rail). On the back side they have a plastic stop that snaps onto the bar. Put the device on the rail, hooking it with a notch on the back wall, press the bottom part with your finger. After clicking, the element is set. It remains to connect it. They do it according to the plan. The corresponding wires are inserted into the terminals and the contact is pressed with a screwdriver, tightening the screw. It is not necessary to tighten it strongly – you can transfer the wire.
They work when the power is off, all switches are switched to the “off” position. try do not grab wires with both hands. Having connected several elements, turn on the power (input switch), then turn on the installed elements in turn, checking them for the absence of a short circuit (short circuit).
The phase from the input is fed to the input machine, from its output it goes to the corresponding input of the RCD (put a jumper with a copper wire of the selected section). In some circuits, the neutral wire from the water is fed directly to the corresponding input of the RCD, and from its output it goes to the bus. The phase wire from the output of the protective device is connected to the connecting comb of the machines.
In modern schemes input machine put two-pole: it must simultaneously turn off both wires (phase and zero) in order to completely de-energize the network in the event of a malfunction: it is safer this way and these are the latest electrical safety requirements. Then the RCD switching circuit looks like in the photo below.
See the video for installing an RCD on a DIN rail.
In any scheme, the protective ground wire is connected to its own bus, where similar conductors from electrical appliances are connected. The presence of grounding is a sign of a safe network and it is vital to do it. Literally.
For information on how to properly connect the RCD, see the video tutorial.
When assembling the shield yourself, please note that the input machine and the meter will be sealed by the energy supply organization. If the meter has a special screw on which a seal is attached, then the input machine does not have such devices. If it is not possible to seal it, you will either be denied launch, or the entire shield will be sealed. Therefore, inside the common shield they put a box in one or two places (depending on the size and type of the machine), and an input machine is attached to it. This box is sealed upon acceptance.
Individual machines are installed on rails exactly like RCDs: they are pressed against the rail until they click. Depending on the type of machine (one or two poles – wires), the corresponding wires are connected to them. What are the machines, and how do devices for a single and three-phase network differ, see the video, the choice of the rating of the circuit breaker is described here.
After the required number of devices are installed on the mounting rail, their inputs are connected. As mentioned earlier, this can be done with wire jumpers or a special connecting comb. How the wire connection looks like, see the photo.
There are two ways to make jumpers:
- Cut the conductors of the desired segments, expose their edges and bend with an arc. Insert two conductors into one terminal, then tighten.
- Take a sufficiently long conductor, after 4-5 cm, strip 1-1,5 cm of insulation. Take the round-nose pliers and bend the bare conductors so that you get interconnected arcs. Insert these exposed areas into the appropriate sockets and tighten.
They do this, but electricians talk about the poor quality of the connection. It is safer to use special tires. Under them on the case there are special connectors (narrow slots, closer to the front edge), into which the bus contacts are inserted. These tires are sold by the meter, cut into pieces of the required length with ordinary wire cutters. After inserting it and installing the supply conductor in the first of the machines, twist the contacts on all connected devices. See the video on how to connect the machines in the shield using a bus.
A phase wire is connected to the output of the machines, which goes to the load: to household appliances, to sockets, switches, etc. Actually, the assembly of the shield is completed.
The choice of machines in the house or apartment shield
Three types of devices are used in the electrical panel:
- Machine. Turns off and turns on the power in manual mode, and also works (breaks the circuit) in case of a short circuit in the circuit.
- WHO (safety shutdown device). It controls the leakage current that occurs when the insulation breaks down or if someone grabs the wires. When one of these situations occurs, the circuit breaks.
- Dif. machine (differential machine). This is a device that combines two in one housing: it controls both the presence of short circuit and leakage current.
Differential machines are usually put instead of a bunch – RCD + machine. This saves space in the panel – it is required less by one module. Sometimes this is important: for example, you need to turn on another power line, and there is no place for installation, as there is no free machine.
In general, two devices are often installed. Firstly, it is cheaper (differential machines are more expensive), and secondly, when one of the protective devices is triggered, you know exactly what happened and what to look for: short circuit (if the machine turned off) or leakage and possible overcurrent (it worked RCD). When the difavtomat is triggered, you will not find this. Unless you put a special model that has a checkbox showing what kind of malfunction the device worked on.
Automata protection
Circuit breakers selected by current, which is necessary for consumers of this group. It is simply calculated. Add up the maximum power of all devices connected at the same time in the group, divide by the mains voltage – 220 V, you get the required current power. Take the rating of the device a little more, otherwise, when all loads are turned on, it will turn off due to overload.
For example, adding up the power of all devices in the group, we got a total value of 6,5 kW (6500 W). We divide by 220 V, we get 6500 W / 220 V = 29,54 A.
The current ratings of the automata can be as follows: (in A) 6, 10, 16, 20, 25, 32, 40, 50, 63. The closest larger one to the set value is 32 A. We are looking for this.
Types and types of RCD
RCD has two types of action: electronic and electro-mechanical. The difference in price for a device with the same parameters is large, but electronic-mechanical ones are more expensive. But you need to purchase them for a shield in a house or apartment. There is only one reason: they are more reliable, since they work regardless of the presence of power, and electronic ones require power to work.
For example, the situation is as follows: you are repairing the wiring, for example, a socket and de-energized the network for this, that is, you turned off the introductory machine. In the process, the insulation was damaged somewhere. If an electro-mechanical RCD is installed, it will work even if there is no power. You will understand that you did something wrong and will look for the reason. An electronic one without power is inoperable and turning on a network with damaged insulation can have problems.
To understand which of the devices is in front of you, it is enough to have a small battery and a couple of wires on hand. You supply power from the battery to any pair of RCD contacts. The electro-mechanical will work, the electronic will not. More about this in the video.
Further, RCDs are distinguished by the type of current to which they react:
- type AC – alternating sinusoidal current;
- type A – alternating current + pulsating direct;
- type B – AC + pulsating DC + rectified current.
It turns out that type B gives the most complete protectionbut these devices are very expensive. For a house or apartment shield, it’s quite enough, type A, but not AC, which are mostly sold because they are cheaper.
Except type RCD, it is selected by current. And in two ways: rated and leakage. Rated – this is one that can pass through the contacts and not destroy (fuse) them. The rated current of the RCD is taken one step higher than the rated current of the machine installed in tandem with it. If the machine is needed for 25 A, then take the RCD for 40 A.
In terms of leakage current, it is still simpler: only two ratings are put in electrical switchboards for an apartment and a house – 10 mA and 30 mA. 10 mA is put on a line with one device, for example, a gas boiler, a washing machine, etc. as well as in rooms where a high degree of protection is needed: in a nursery or bathroom. Accordingly, an RCD of 30 milliamps is installed in lines that include several consumers (devices) – on sockets in the kitchen and rooms. Such protection is rarely placed on the lighting line: there is no need, except perhaps on the street or in the garage.
RCDs are also different in time delay operation. They are of two types:
- S – Selective. It works after a certain time after the appearance of the leakage current (quite a long period of time). They are usually placed at the entrance. Then, in the event of an emergency, the device on the damaged line is first turned off. If the leakage current remains, then the “senior” selective RCD will work – usually this is the one that is at the input.
- J – It works with a delay (protection against accidental currents), but with much less. This type of RCD is put into groups.
Differential machines are the same types as WHO and are chosen in exactly the same way. Only when determining the power by current, you immediately consider the load and determine the nominal value.
For a few explanations on the installation of a built-in cabinet for a shield, the connection procedure, see the video from a practitioner and a generalist.
One important detail that is important for safety. On the RCD or differential machine there is a “test” button. When it is pressed, a leakage current is artificially created and the device should work, the switch switches to the “off” position and the line is de-energized. This is how the functionality is checked. This must be done at least once a month: to be sure of the reliability of protection. In turn, check all the RCDs in the circuit. It is important.
Probably, this is all the information that is needed to assemble the electrical panel with your own hands. Maybe you still need to learn more about how to break the load into groups, read about it here.