In order to ensure the supply of electricity to residents of apartment buildings, often use a shield that is installed at the entrance of the house. In order to monitor the metering of consumed electricity, also set the meter. And even in most cases, everything happens exactly as described above, sometimes the meter is installed on the dashboard located in the apartment.
This option is actually much better, as in good climatic conditions, the meter is working properly, and, moreover, is protected from vandals.
- 1 Functions of automata
2 How to connect the machine
- 2.1 Connecting the machine to the meter
- 2.2 Connecting the machine to the dashboard
- 3 Design features
- 4 The legal side of the issue
Functions of automata
Circuit breakers, often referred to simply as automata, are used to protect electrical wiring. They are installed directly in the electrical circuit from the energy source to the load and serve to disconnect the circuit during short-circuits and overloads. Also, when the shields are located in the apartment, the machine guns are protected because someone from the residents hooked or accidentally broke them. In the past, protection circuit breakers were not installed in apartments, and electrical traffic jams were the best means of ensuring security.
Proper replacement of older models with more modern ones will successfully protect wiring for many years. For the same to use the function of the switch, you, as a rule, just need to press the red button on the case. To turn it on next is a white button. Sometimes used leverin which the top position indicates on, and the bottom - off.
It must be remembered that all protection devices must, simply, be required to disconnect the network, which is damaged by a short circuit as quickly as possible, the shutdown time should be minimal. Overloads formed in the network, lead to the fact that the wires and cables are heated above the permissible temperature at which operation is possible.
According to the rules, this temperature cannot be higher than 65 degrees with a long current load. Permissible electric current loads in such cases, according to the rules and laws of physics, depend on the cross section of the wires themselves, as well as on other auxiliary parameters.
Overload wire insulation dries from heat and leads to short circuits. Internal wiring closures. They occur directly between its current-carrying veins. In this case, if you do not have a properly installed and connected circuit breaker on the panel, this may cause a fire.
Among other things, short circuits occur not only because of overload, as you might think, but also due to short circuits in switches and sockets, with poor quality of other wiring devices.
Each machine has its own limited service life. What is it equal to? It is determined by the number of trips of short circuits that are made by the machine. The function of the fuse in the device performs an electromagnetic and thermal relay. It is also called a release. It is embedded in the body of the machine, being an integral part of it.
Specifically, the thermal relay shuts off the circuit when currents flow through it that exceed the rated current of the release. The value of the rated current is usually indicated in the most visible place on the surface of the body of the machine.
It turns out that the current release serves to protect against overload. However, if the overload is small current release it works in a much longer time, while with significant ones it takes less. The release consists of a plate (bimetallic), which is bent and turns off the device as it overloads, if the overload is not eliminated. When you need to power up the device, you will first need to troubleshoot the overload, and then wait for a while for the bimetallic plate to cool down.
An electromagnetic release is able to operate without a time delay, as opposed to a thermal one. When the set value is reached by an electric current, the electromagnetic release immediately switches off the device. This value is called the setpoint current. It is standardized ten times the rated current.
How to connect the machine
Actually now we come to the question of how to connect machines. Circuit breakers are installed, as a rule, before loads. That is, in the dashboard or assembly, feeding groups of power consumers. In the apartment panels they are placed after the counter. For safety, the meter and the wires to it must be protected. This is done when using machines on the supply panel. It is also possible to apply certain operations at the KTPN substation.
Single-phase circuit breakers are usually installed in a phase conductor. In all current-carrying wires of the phases are installed two-phase and three-phase. The zero wire is usually attached to a special zero terminal in the shield, and then directly to the loads. Phase wire from the zero can be distinguished by the voltage indicator. If you make a touch of the phase wire, the indicator will have a glow of a neon lamp. If you make a touch of zero - no.
It is important to understand that neon lamp indicators when voltage is applied to the element under test, it can be active even in the absence of voltage on it. In this embodiment, it is necessary to isolate the element under test from the current-carrying parts that are located nearby and are under test at that time under voltage. If it is impossible to do this, look for other methods of verification, and if it is impossible for others to consider a circuit that has induced voltage, the circuit on which real voltage acts.
It is important to know that you cannot use test lamps to check for the presence of voltage. Safety will tell us that any conductive conductor, if you do not know his condition, should always be considered as being under voltage.
The circuit breaker is connected to the circuit so that the phase wire fits into the fixed parts of the circuit breaker, and the outgoing, i.e. load wire to the moving part of the circuit breaker. This is due to safety. When disconnecting the circuit, there should be no voltage on the moving parts of the machine.
Insofar as phase wire it is important that you connect to fixed parts, then these parts are usually located at the top of the case. This means that the phase conductor must be connected to the upper clamping screw. As you might guess, the load wire is connected to the bottom. Of course, there are also constructions of automata with the opposite arrangement, and then it can be advised to determine the correct connection of wires by visual signs.
So, highlighting the basic rules for connecting the circuit breaker, you should select the items to which it can be connected to work. And this:
Connecting the machine to the meter
The machine must be connected to the meter immediately after it. The phase wire leaving the meter is connected to the circuit breaker. Zero wire does not enter the machine, it is connected to a special block in the shield, conventionally called zero. The machine serves as a safety device in the same way as a switching device.
Connecting the machine to the dashboard
But how to connect the machine in the dashboard. We give the scheme, it can be quite complicated at first glance. In the electrical panel, the circuit breakers must be connected to a cut, which goes to all phase loads. At the same time, also from the input automaton in the same shield should connect all outgoing machineswhich stand in chains in parallel. The phase wire of the input automat is connected to all upper contacts of all parallel automata. Here the rule of selectivity is observed.
What is this rule? You can tell a lot about selectivity. But we are interested in precisely the rule of its application. According to him, if the shield uses more than one protection device, then this means that the upstream machine simply must be more in the rated breaking current than the downstream one. At the same time the zero wire of the input cable is connected without any break to a special terminal strip in the shield. It should be a scratch pad. The same block connects the neutral conductors of the wires to the loads, as well as outgoing cables.
Very often the cable has a triple ground conductor in its design. In this case, there is a so-called additional block of earth. All three earthen wires of outgoing wires and cables are connected to this block.
There are machines of various designs. Consider different options:
- single-pole used in the network of 220 volts. What is the difference? They connect only one single phase wire.
- two-pole also used in the network, which, as in the previous case, is 220 volts, their main difference is that in their circuit two wires are connected. Phase and zero.
- three-pole can be used in a 380 volt network. Three ordinary phase wires are connected in such devices.
- four-pole circuit breakers. They are applied, as well as three-pole, in a network of 380 volts. They connect three standard phase wires, and in addition to them one zero.
The most common in the home network are single pole and double pole. Optimally in such a network to use a two-pole circuit breaker, and that is what we discussed in the article. This is because:
- It includes two wires at once. As mentioned above, these wires are zero and phase. If the user has such a need, then it is permissible to break the chain completely. If overvoltage occurs at zero, then if we turn off the machine, we will be able to save the equipment.
- Double pole circuit breaker is easy to use. Also easy to install. It is installed with just one click on the so-called din-rail.
- Wires in two-pole machines are easy to connect and, if necessary, disconnect. To do this, just unscrew the four screws.
- The machine can easily be changed to a RCD or differential-automatic switch if desired. The connection method and the length of the wires is the same.
The legal side of the issue
Perhaps someone will be interested in the requirements of the law. They are that the metering devices, without exception must be sealed. That is why before you decide to break the seals, you must obtain permission from the management company for this. In an emergency, you need to call the emergency service.
It can also help in legal matters. They have the right to remove the seal. As well as the issuance of a document confirming this. The machine included in the wiring in front of the meter is sealed only if it is installed in the apartment. In this case, the design of the circuit breaker installed in the apartment should provide for the possibility of sealing it.
After completion of the work, it is important to promptly invite a responsible representative from your management company or the grid company. It is necessary that restore the counter seal. And if necessary, and also the circuit breaker itself. The arriving representative at the same time may require to present you an act of the emergency service. In another case, you may require a passport to the meter.
By the way, it will be curious to know that 99 percent of apartments in this country are not equipped with UZO, and statistics on cases of injury to people by electric current, in which there was a fatal outcome in everyday life are missing. For one million people, on average per year there are two or three cases of electric shock, unfortunately fatalities. Such cases occur at work or, in another version, on the street, with a very gross violation of electrical safety rules. Therefore, everything is not so bad.
Do not forget that when you install the circuit breaker yourself you will save money. Calling an electrician, installing a double-pole machine, installing a din-rail, connecting a ground contact (pass-through) - all this can cost you a sum, exceeding 1000 rubles.
Of course, if you deal with the installation, you will strictly follow the rules and safety precautions and strictly, then the money will remain in your pocket, and you yourself and subsequently will be able to carry out such technical operations.