From the point of view of specialists in the field of electrical engineering, the question "what current is in the outlet?" is not entirely correct. The fact is that if a consumer is not connected to the mains, then no current flows in it, since in this case the electrical circuit is open.
However, if you do not go into disputes about the accepted terminology, then the rated current is the most important parameter of any electrical equipment. The choice of elements of the electrical network, methods of their installation, as well as the characteristics of consumers should be carried out taking into account these parameters.
The main characteristics of electricity in household networks
To date, there are several criteria that determine the quality of electricity in household electrical networks with a voltage of 220 V. All these characteristics are clearly defined in GOST 32144-2013. The most important of them are:
- Frequency deviation.
- Slow changes as well as voltage fluctuations and dips.
- Non-sinusoidal voltage.
- Voltage unbalance in three-phase networks.
At arrangement of electrical wiring own apartment, there is no need to take into account all the parameters of power quality. It is enough to know its main characteristics, which can be checked using simple and fairly cheap measuring instruments.
These parameters include the frequency of the supply network (direct or alternating current), the magnitude of the voltage, as well as the power of the connected consumers.
Mains frequency
Currently, most consumers are powered by alternating voltage. Its wide distribution was facilitated by the possibility of transmitting such energy over long distances. This quality is ensured by the ability of alternating current to flow in electrical circuits containing capacitances, which are inevitably present in extended power lines. As is known from the general course of physics, direct current does not have the ability to flow through a circuit that has capacitors in its composition.
Since AC outlets use alternating current, one of its most important characteristics is frequency.
In our country, it is customary to use AC voltage with a frequency of 50 Hz.
It is worth noting. Some consumers operate on increased frequency voltage. This allows you to significantly reduce their weight and size and improve some specific technical characteristics. To power such devices, frequency converters are used, which are built-in or purchased separately.
You can check the frequency in the network using special devices - frequency meters, however, for practical purposes, such measurements are used quite rarely. It is much more important to know how many amperes flow in the electrical network and what is the magnitude of its voltage.
Mains voltage
Most people know that in ordinary electrical outlet AC voltage 220 V is used.
To power more powerful consumers, a three-phase network can be used. In this case, the potential difference between the phases is 380 V, and between the phase and zero - the same 220 V. As a matter of fact, the state power system is built on the use of three-phase power networks. Their separation into single-phase lines occurs immediately before connecting consumers.
Due to an uneven load on different phases, a distortion may occur, causing current to flow in a common neutral wire, as well as a decrease or increase in voltage on individual consumers.
Important! If the voltage in the outlet goes beyond the permissible values, then significant difficulties may arise in the operation of electrical equipment, up to turning it off by built-in automatic protection or failure of the electrical installation.
Rated consumer current
Any device used in electrical networks of direct or alternating voltage has certain parameters. One of them is the rated current.
This characteristic indicates how many amperes can be passed through the main electrical circuit of the device for a long time.
In this regard, electrical outlets are no exception to the rule. They can also be divided according to the rated current. Standard values for single-phase household devices are 6, 10, 16, 25 and 32 amps.
Sockets for 6 - 16 amperes are used most often and can be combined into groups that receive power through a dedicated line from the apartment electrical panel. Devices with a rated current of 25 amperes are designed to power more powerful consumers.
As for 32 amp sockets, they are produced in most cases in a three-phase version and are designed to connect particularly powerful consumers, such as electric stoves or hobs.
Rated current calculation
When an electric current flows, the conductor heats up significantly, which often causes failure of the electrical network elements and even leads to a fire. The intensity of heating depends on two factors: the square of the current, as well as the electrical resistance of the load. It is easy to guess that the most powerful consumers have a minimum resistance that allows significant currents to pass.
Calculate what current in the outlet can be based on the power of the device connected to it. In this case:
I = P/U, (A).
where P is the active power of the consumer, W.
U is the mains voltage, V.
This formula is equally suitable for determining current with alternating and constant voltage.
Methods for measuring voltage and current
To check the compliance of the voltage of the mains with the established requirements, as well as to find out how many amperes flow through one or another of its elements, various devices are used to measure current and voltage.
Indicator screwdriver
The cheapest device that allows you to check the presence of potential at the socket contacts is an ordinary indicator screwdriver. At the same time, it is impossible to find out how many volts are applied between the contacts.
In a normally working network, when the indicator touches the phase contact of the socket, the LED built into the handle of the voltage indicator glows brightly; when touching the neutral wire, there is no such glow. This method can only be used to determine the presence of voltage in the phase wire.
Its significant disadvantages are the impossibility of monitoring the integrity of the neutral conductor, the magnitude of the voltage, as well as the susceptibility of the measurement accuracy to the influence of "pickup" created by the magnetic fields of electrical wires passing nearby. Thus, the indicator can glow even if there is no rated voltage on the phase contact of the socket.
Tester
A more accurate way to measure voltage is to use special devices - voltmeters (often testers or multimeters are used to measure several quantities: voltage, current, resistance, capacitor capacitance, etc.).
Such a device is connected in parallel to the network (its probes are inserted into the outlet in the absence of consumers connected to it). Using such devices, you can find out how many volts of direct or alternating voltage are applied to the socket contacts.
The current in an outlet can be measured using a multimeter connected in series with the mains as an ammeter.
Important! A device configured to measure current must not be connected in parallel to the mains. It may fail.
Measuring clamps
The main disadvantage of using an ammeter is the difficulty of connecting it. Therefore, in many cases, a clamp meter can be used to check how many amps are flowing in a wire. The main advantage of this device is the absence of the need to open the circuit and turn off the electrical equipment when using it.
Thus, among all the characteristics of electricity in household electrical networks, the most important are frequency, voltage, and rated current.
You can find out what current is in the outlet using measuring instruments or analytically using the formula.
