To understand how to connect the machine in the shield, you need to familiarize yourself with the minimum requirements for electrical safety, fire protection. Also, knowledge of the basics of electrical engineering will be needed to calculate the required load from electrical appliances. It is important to choose the type of appliance, the rating of its operation and the number of safety devices.
Purpose of electrical protection
To understand how to connect the machine in the shield, you need to familiarize yourself with its purpose and types. The electrical panel houses all the equipment for distributing power to household appliances. Here are the terminal blocks, electricity meter, RCD device, automatic machines, relays.
Holds din rail equipment made of conductive material and grounded at one point. They try to arrange the electrical switchboard at the entrance to the apartment or from the street in a private house. The machine itself refers to sophisticated devices. Certain requirements are imposed on it, depending on the purpose of the device.
The modern automatic machine for the meter protects the wiring and equipment from short circuits and can even save people from electric shock. It is forbidden to make home-made fasteners for the device in the shield in order to comply with safety rules when working on live devices. How to connect the machine in the shield, knows a specialist who has the appropriate tolerance group. But if you contact the master is unprofitable, and not profitable, then you can perform the replacement yourself.
It is also important to know how to connect the machine in the dashboard, before buying and installing household appliances. So for heaters choose more powerful safety systems, and for low-power devices you will need to add separate machines. For the latter they put electronic circuit breakers. It is often advisable to install an RCD to provide a high degree of reliability of protective devices.
In most cases, electricians provide a standard scheme for connecting wires that are energized - from above. However, often the box for the meter is mounted by specialists who are not related to electricity, and they bring the phases from the bottom of the machine. Therefore, before replacing failed devices, it is necessary to measure the voltage supply with a working voltmeter.
General information
The box for the counter in apartments contains a two-wire circuit for connecting electrical appliances. It is simple and contains a supply wire - “phase”, and a discharge wire - “neutral” or “zero”. Modern standards provide for the use of "grounding" to protect against short circuits. Devices such as a washing machine, a refrigerator, an electric furnace, are necessarily connected in a three-wire circuit.
The ground wire designation is common - yellow-green stripes. To connect the machine, it does not matter which terminal the phase wire will be connected to. But it is recommended to let it down from above, so that the next inexperienced specialist does not fall under the action of the current, grabbing the wire from the bottom of the machine out of habit. Before any work, it is required to turn off the input switch, but many electricians carry out live work.
The wiring and connection must be carried out by a specialist with appropriate education and tolerances. Dealing with the nuances of installing some automatic machines is not easy, especially if the consumer decided to install a separate switch for each outlet and light bulb. Some organizations may provide a complete switchboard assembly. But in this case, it is necessary to provide for the possibility of installing additional machines in the future, if you want to change the general electrical circuit.
Instrument replacement recommendations
To install and connect the machine you will need:
- Tools: wire cutters, flat and Phillips screwdrivers, multimeter.
- The wire, designed for the used household appliance, the cross-section should exceed the load twice. Installation is carried out in an already installed shield, so the din-rail is not taken into account.
- The machine must have standard mounts. Wires are laid in a corrugated hose to protect against mechanical damage.
The insulation is removed from the cable, the length of the stripped wire is selected no more than 10 mm so that the exposed parts are out of the reach of the hands and do not touch the metal parts. Grounding is recommended. In old houses, it may be absent altogether. But for your own safety you need to install it.
To connect the "earth" in the shield uses a common open terminal block for each lead wire. The lead-out conductor is one larger section. "Neutral" is also recommended to perform a single block, but a closed type. It often has a potential hazardous to human life. Installation of the shield begins with the connection of the earth wire, then the neutral one. At the end, put phase.
In the presence of several automatic machines, jumpers are used, which they begin to set from the input switch. The corrugated hose inside the shield is only needed for non-standard cable laying, when there is a risk of damage to it. Corrugation is not applied to short sections.
The jumper is replaced by a common distribution plate, available from any electric store. To protect contacts from contact, a box for an automatic machine made of plastic or another dielectric is used.
Device selection
The load on the machine should be less than the calculated one. Demand is 10, 16, 20 amperes. Higher denominations are usually placed under boilers, home heaters, and ovens. For standard devices, 10 amperes are suitable: PC, TV, iron or hairdryer. However, if several loads can be connected to one device, the resulting value is obtained by adding all the ratings.
It is not recommended to use many devices, sockets, lighting lamps on one machine. If one link fails, the socket can fuse without turning off the fuse. So a 2-ampere household appliance can start to consume 5 amperes when there is a malfunction in the board. The machine, designed for 16 amperes, will not work. Even the insulation on the wires may melt.
Therefore, before choosing a machine, it is recommended to consult with an electrician on the choice of type of protective device. They differ in response speed, purpose of protection, connection, internal device, number of phases. For installation in the shield, the phase wire is fed from the fixed contact side, the marking is often already indicated on the machine body.
Types of switches
The device of the circuit breaker depends on its type: the response speed can be milliseconds for magnetic switches and several hours for machines with a bimetal plate. The letter in the designation matters when choosing a protective device. For home, it is recommended to install types B, C.
Classes Z (for electronic devices), D (for electric motors and inductors), and A (for extended conductors) are rarely found in everyday life. Experienced electricians recommend combining circuit breakers with RCD devices (residual current circuit breakers ) or using difavtomaty. Distinguish electromechanical and electronic protection. The second is less reliable and quickly fails, tracks and internal elements burn out with significant overloads.
When choosing the type of machine, it is recommended to take into account that the current rating through the wiring section must exceed the possible overload and the maximum value of the circuit breaker. If the machine has a high speed and sensitivity, then it will have a higher cost. However, not in all cases it will be reliable; erroneous responses to increased load are possible.
Such a problem can be identified only in each specific case when analyzing the type of household appliance and additional parallel loads that are simultaneously connected to the network.
Design Features
The circuit breaker device is of the following types:
- The electronic principle of action.
- Electromechanical.
- Electromagnetic.
For the home, they often choose budget options for the execution of automatic machines of the electromagnetic principle of action. The main working part is a bimetallic plate. Choosing a switch is appropriate in proportion to the cost of technology. For ordinary functions, ordinary automatic machines are suitable, but if a specific electrician is used, it is recommended not to save on protective equipment.
Fuses are used in production to this day in the most critical parts of the electrical circuit. RCD primarily protects the human body from electric shock. From the basics of electrical engineering it is known that the current in the serial circuit is the same. The principle of operation of the device is based on a comparison of the current of the phase and neutral wires. The so-called differential current arising at the time of the defeat of a person is detected.
However, an RCD can often fail in the operation of large inductances or capacitors. The operation of the machine is not affected by the method of connecting the phase and neutral in a single-pole design. Overload is measured, potential difference is not taken into account.
Common mistakes
At the end of the work, they received a switchboard, electrical installation in which was performed according to all the rules. But the machine still knocks out for no apparent reason or the equipment in the house does not work. Such a result is possible with the erroneous fulfillment of certain points.
A simple and solvable problem is the lack of contact at the terminals of the machine. This is possible with insufficiently removed wire insulation, when the clamping jaws hit the dielectric part. The bare end should protrude slightly outside the machine, and they must be protected by a dielectric housing worn over the switch.
Suppose that the shield in the apartment has a non-standard connection diagram, and during installation they could put the neutral of the devices on an earth conductor. This type of malfunction occurs only for beginners, but it can lead to the failure of an expensive device: a TV, PC, charger or other type of equipment.
Burnout pads can occur when you turn on powerful appliances in the network, when the wire core on the machine is not stretched and has poor contact. From a large load breaks a spark, as a result, the device in this place heats up, but does not knock out. Prolonged operation in this mode leads to the fact that the plastic begins to melt until it ignites or shorts to a grounded case.
A typical error occurs when the cross-section of the connected wires varies slightly. In this case, a loose contact is possible, due to which a spark will pierce. Ultimately, this will end with the result described above. To avoid a fire, you need a fireproof switchboard. The electrical installation is erroneous when connecting several sources of different power to one machine. The higher the difference between the most powerful device and the weakest, the less reliable contact is obtained in the jaws.
Work recommendations
Convenience of installation is achieved when forming wires in the form of a U-shaped arc at the connection point. This facilitates the task of holding the conductor at the time of tightening the terminal. Before making a connection, be sure to turn off the input switch, if possible.
To connect the machines, you can use your own jumpers of the same section. However, a common tire with standard mounts would be the best solution. When tightening single-core wires, no questions arise, but difficulties are possible when using multi-core conductors.
It will be necessary to terminate the cores before tightening to the terminal. For this, a special crimping device is used, which you can buy in electrician stores. Standard sections are marked on his lips, choosing the appropriate part, they achieve the best contact after the crimping procedure. A smaller diameter will lead to a partial cable break, and a larger one will not give the desired result.
For crimping, special lugs for a specific wire diameter can be used. There is a second method - soldering. It is longer, but less reliable and is used in low-power circuits. The junction is soft. At first, the terminals will be tightened to the maximum, but after some time they will weaken due to the fact that the solder starts to “float”. Bad contact threatens a fire.
What should not be done?
Often in old buildings, aluminum wires were used, and new wiring diagrams have copper conductors. Inexperienced electricians can connect two metals to twist, which over time can result in a wiring replacement. This is due to a chemical reaction between two different substances: aluminum and copper.
An oxidizing process occurs, the rate of which depends on the load in this circuit. If there is a need for such a connection, then installation can be done through insulated terminal blocks. However, after a long time, the bolts will have to be pulled out, they will loosen. Twisting is not recommended for use in the shield. And it’s better to sign each machine, after a few years you can forget about the purpose of the device.
You can reduce the load on the machine by using economical household appliances and lighting lamps. This approach allows you not to think about the possibility of melting insulation. Only the risk of a short circuit will remain.
In case of malfunction
If the machine is knocked out, it is not recommended to turn it on immediately. First, you need to assess the possible cause of the malfunction: a recently hung shelf, a new purchased device, or the absence of previous events. Overload could occur due to burnout of a part of the wire in monolithic structures. To search for a problem place, there are devices available to specialist electricians. This is true when the cost of opening the wall is much higher than the cost of work to diagnose electrical equipment at home.
When the machine breaks out, it is recommended to use an ohmmeter and check whether there is a short circuit to ground or between the conductors: phase and neutral. Before that, all household appliances are turned off. The inclusion in the circuit is carried out according to one device, while measuring the current through the wire with the help of electric clamps.
Exceeding the load rating of the machine requires either a replacement of the circuit breaker itself, or a change in the location of its connection. During diagnostics, you can check the wire with your hands without a measuring device, holding the insulation while consumers are working. If it heats up, then there is an overestimated current in the circuit.