Each room has several power points for the operation of various devices. The technique works by means of electric current, which is conducted through specially installed cables - conductors. The quality of the voltage, stability and safety of use depend on the quality of the network elements and the method of connection. There are two main methods - parallel and sequential. Each has its own advantages and disadvantages, which it is better to familiarize yourself with in advance.
Basic electrical quantities of the circuit
- sources: transformers, electrical installations, batteries, generators, accumulators and others;
- receivers: directly equipment - lamps, motors, heaters, inductors, the like;
- intermediate links: wires, devices.
The main quantities by which the properties of electrical circuits are established are voltage, resistance and current. In conductors, electricity is a set of electric charges moving in a given direction. The current in the network means the intensity or force, which is measured by the number of charges simultaneously passing through the cross-section of the conductor.
Voltage is the amount of electrical energy required to move one charge from one point to another. Expressed in Volts. Resistance is the force acting on the flow of electrical charges during the movement of conductors. It is written in Ohms.
Mutual dependence of electrical quantities
In addition to the basic rule in electrical engineering, Kirchhoff's Laws are used. One says that the sum of the input currents is equal to the sum of the output currents. The second is that the sum of the EMF is equal to the sum of the voltage drops across the internal elements of the electrical circuit.
Kirchhoff's laws allow you to establish the relationship between the currents passing through the nodes of electrical wiring and the currents at the entrance to the loop circuit. Analysis and calculations are carried out according to the following algorithm:
- The total number of branches and nodes of a specific electrical network is established.
- The conditionally positive directions of currents in the wiring are randomly selected, the corresponding marks are put on the diagram.
- To obtain the equation, the positive directions of the contour traversal are marked in free order;
- An equation is drawn up according to the Kirchhoff rules to obtain the result.
The solution of the constructed tasks will allow to determine the number and value of currents in a specific electrical circuit.
Using Ohm's and Kirchhoff's laws, electricians assess the condition of the network, its performance and power. In practice, live formulas are rarely used. Practicing electricians are more fluent in their characteristics. Novice editors may find it difficult to orientate at a time in all indicators and relationships, it is more convenient to have some auxiliary materials at hand.
Parallel connection of conductors
To check the intensity of the passage of current with such a connection, two light bulbs are connected to the parallel network (the indicators must be identical - resistance, voltage). To test and check the result, an ammeter (a device that measures current) is connected to each. The third device is fed to the network as a whole in order to see the indicator on the entire network. Additional elements - food, key.
After the circuit is assembled, the power is activated with a key and the results are compared on the ammeters. In general, the indicator should be equal to the sum of the two connected to the lamps. In this case, it is considered that the system is working properly - the voltage is supplied in the normal mode during the parallel connection.
If a short circuit occurs in one area, the bulbs will remain in working condition. The current flows in a closed loop from both sides. Repairs will be necessary anyway, but light and power will remain.
If you connect a voltmeter to the specified system, you can estimate the resistance indicators of the network. An equivalent indicator will indicate the level of resistance of the network at the same current intensity.
Series connection of conductors
The resistance value can vary. If the load changes at one of the series connection points, the resistance level will also change. As a result, the current indicator will change.
The main disadvantage of such an electrical circuit is that if a failure occurs in one of the sections (breakdown, short circuit), the elements following it will cease to function. The connection diagram is clearly presented in ordinary New Year's garlands - when one contact or wire breaks anywhere, the rest stop working.
When connecting wires in series, the end of one cable is connected to the beginning of the next. The key difference between the electrical circuit is the absence of branching, one electric current passes through the sections. In this case, the potential difference of the resistor is explained by the total voltage for each individual resistor (contact, section, power point).
Laws of serial and parallel connection of conductors
The rules that explain the "behavior" of conductors in series and parallel connections include the basic laws of electrical engineering and some features. The latter are not always obvious to beginners, so they are taken apart as separate laws. When working with conductor diagrams, consider the following:
- Serial connection implies the same currents in each section.
- Ohm's law has its own meaning for each type of connection.For example, with a sequential method of switching on, the voltage will be equal to the sum of the voltages of all sections of the network.
- The total resistance of the electrical circuit with alternate connection will be equal to the sum of the resistance values of the elements, does not depend on the number of conductors and power points.
- Parallel method - the voltage of the electrical circuit is equal to the voltage on each individual element, it is not summed up, but remains the same.
- The current strength for this connection method is determined by the sum of the values of the currents of the connection sections.
These laws are used when building an indoor wiring diagram.
In order to optimize the load, not to create excessive stress in individual parts, check the optimality of each type of connection in a particular situation.
Mixed connection of conductors
Typically, wiring uses parallel and serial connections at the same time. This method of connecting wires is called mixed or combined. When constructing the initial power supply scheme in the room, where the number and location of power points (sockets, switches, transformers) are indicated, the need for each of the types of connection in different areas is taken into account.
Electrical wiring is rarely simple. Often, a complex circuit is obtained from many different sections and connections. Therefore, when making a plan, it is important to understand the advantages and disadvantages of wire connection types in order to make optimal use of each. To do this, the circuit is divided into sections and in each case, they select their own method of inserting wires.
How to choose a connection type
The electrical energy consumed in the apartment comes from the general electrical panel. The amount of consumed current is measured by a meter. The lead-in wire to the premises has a large cross-section and is the main "supplier" of electricity to the apartment. The next ones are taken with lower rates, since the load on them is reduced due to distribution.
The main cable is fed into a special junction box, from which wiring is made to rooms and bathrooms. At this stage, it is necessary to determine what type of wire connection will be used: serial, parallel, combined.
There is no categorical prohibition on building wiring in an apartment in one way or another. However, you should consider the practical application of each circuit, disadvantages, advantages and opportunities.
Mixed wiring is the most suitable and commonly used option. A cable is connected from the common panel to the distribution box, then several distribution nodes (in each room) are connected to the parallel network. Further - in the rooms, the power points are connected in series.
Sequential inclusion of elements allows you to significantly save on materials when installing electrical wiring. Therefore, despite certain disadvantages, the method is used in small rooms. In small areas, it is easier to identify the place of breakdown than in the apartment as a whole.
Parallel connection visually represents a ring of wires. If a failure occurs in one section, the current does not stop flowing - the supply occurs on the other side of the circuit. However, this type of connection requires a significant amount of cable to be laid, which is not always convenient.
In some situations, it is advisable to use only a serial connection of wires. For example, in long corridors, several lighting fixtures must be turned on and off at the same time. Daisy chain connection is optimal in this situation. The complexity of replacing a light bulb or unit on a site depends on the type of wiring and the decoration of the room.
When drawing up a diagram of an electrical network in an apartment and buying light bulbs for lighting fixtures, it is important to take into account the voltage level.Series connection means that the voltage is divided equally by the number of bulbs. For example, if two are installed in a row, the value on each will be 110V, not 220V.
When buying a second home, you should make sure that the technical documentation contains a valid wiring diagram. Having a plan will allow you to safely make repairs and correctly connect new power points, lamps.
Electrical installers in complex circuits always use both types of connection. On the one hand, this approach reduces the total amount of consumables. On the other hand, it allows you to realize the advantages of both methods of cable insertion in each specific room. When connecting on your own, it is necessary to understand in detail the aspects of each type, if possible - to consult with the master. Otherwise, there is a high probability of incorrect connection and malfunctions.
