How many Watts are in 1 Ampere and how to convert them: using a formula or using a program

What are watt and volt

1 volt is equal to a unit of voltage created by an electric current at the ends of a conductive device designed to produce 1 watt of heat at a constant electrical characteristic passing through the conductor. The volt characteristic is also defined as the potential difference between two measured points when a charge of one coulomb moves from point A to point B, when work of 1 joule is required.

Volts, watts and amps

1 W is an indicator of power at which work equal to 1 J is performed per second. It turns out that W is considered a derivative of two quantities. Power and voltage have a relationship:

1W = 1V*1A

Formulas

To have an idea of what power is, you need to think logically. If we assume that it is simply force, such a conclusion will be incorrect. To correctly evaluate a physical quantity, it is enough to know that power is the rate at which a device consumes energy.

For example, a lamp can produce bright or dim light, depending on the rate at which energy is consumed. If the brightness is higher, then the consumption is higher, and vice versa.

Attention! The power rating applies to all electrical appliances, but it is not always related to electricity. This is the main difference between the indicators.

Basic current values

Power also comes in:

Thermal – determined by temperature parameters.
Electrical – the indicator is taken into account in electrical appliances, including light bulbs.
Mechanical, determined by the number of horsepower.

All of the above refers to physical characteristics.

You may be interested in Features of the designation of radio components on the diagram

Introduction to the topic of determining quantities

The generally accepted unit for measuring power is the watt (W).
This parameter usually describes the rate of energy conversion or consumption. By definition, power is the ratio of work (energy expended) to the time it is performed. In turn, the unit of energy in the International System of Units (SI) has always been the Joule. The value of “1 watt” in question corresponds to one Joule of work done in 1 second (J/s). For example, in electrical engineering there are special devices, wattmeters, that measure the power of an electric current or electromagnetic signal.

The unit received its name from the surname of the Scots-Irish inventor James Watt (Watt). This creator of the first steam engine first used it in describing the capabilities of a power machine. The watt was adopted in 1882 and largely replaced the traditional units of account that had existed before: foot-pound-force per minute and draft horsepower. The first unit of power corresponded to 2260 watts. As for the second, it is still used today: “metric horsepower” is approximately 735 watts.

As a unit named after a scientist, it follows the spelling rules originally adopted by the SI system. The name watt is written with a lowercase letter, and the designation W (W), including in the designation of non-system units, is written with a capital letter.

The use of the watt is not limited to the field of electrical engineering; it measures the torque of power plants, the flow of thermal and acoustic energy, and the intensity of ionizing radiation.

One watt – is it a lot or a little? Mobile phone transmitters usually have a power of 1 W. Incandescent lamps used in household lamps consume power of 25, 40, 60, 100 W, TV and refrigerator 50–55, microwave and vacuum cleaner 1000, and washing machine 2500 W.

Often in practice it is necessary to convert watts into kilowatts or, conversely, convert kilowatt values into watts.

How are they designated?

W is a watt or a volt, some find it difficult to answer. The designation W was noted already in the century before last in Great Britain. The name of the measure was given in honor of the famous scientist, ideologist of the industrial revolution, James Watt, who was also the creator of the first steam engine.

He spent many years studying this indicator and used horsepower to measure it.

Volt is a unit named after the great physicist Alessandro Volta. A volt is defined as the difference in voltage or potential at the ends of a conductor, as well as between conductive sections of a circuit.

Designation of quantities:

W – watt
V – volt.

It is an accepted abbreviation (abbreviation) in the international system.

Convert Watts (W) to Amps (A).

Converting amperes to kilowatts (single-phase 220V network)

For example, let's take a single-pole circuit breaker with a rated current of 16A. Those. A current of no more than 16A should flow through the machine. In order to determine the maximum possible power that the machine can withstand, you must use the formula:

P = U*I

where: P – power, W (watt);

U – voltage, V (volt);

I – current strength, A (ampere).

We substitute known values into the formula and get the following:

P = 220V*16A = 3520W

The power is obtained in watts. We convert the value into kilowatts, divide 3520W by 1000 and get 3.52kW (kilowatts). Those. the total power of all consumers that will be powered from a machine with a rating of 16A should not exceed 3.52 kW.

Converting kilowatts to amperes (single-phase 220V network)

The power of all consumers must be known:

Washing machine 2400 W, Split system 2.3 kW, microwave oven 750 W. Now we need to convert all the values into one indicator, i.e. convert kW to watts. 1 kW = 1000 W, respectively, Split system 2.3 kW * 1000 = 2300 W. Let's sum up all the values:

2400 W+2300 W+750 W=5450 W

To find the current strength, power 5450W at a network voltage of 220V, we use the power formula P = U*I. Let's transform the formula and get:

I = P/U = 5450W/220V ≈ 24.77A

We see that the rated current of the selected machine must be no less than this value.

Converting amperes to kilowatts (three-phase network 380V)

To determine the power consumption in a three-phase network, the following formula is used:

P = √3*U*I

where: P – power, W (watt);

U – voltage, V (volt);

I – current strength, A (ampere);

It is necessary to determine the power that a three-phase circuit breaker with a rated current of 32A can withstand. We substitute the known values into the formula and get:

P = √3*380V*32A ≈ 21061W

We convert watts to kilowatts by dividing 21061W by 1000 and find that the power is approximately 21kW. Those. a three-phase 32A circuit breaker can withstand a load of 21 kW

Converting kilowatts to amperes (three-phase 380V network)

The current of the machine is determined by the following expression:

I = P/(√3*U)

The power of a three-phase consumer is known, which is equal to 5 kW. The power in watts will be 5kW*1000 = 5000W. Determine the current strength:

I = 5000W/(√3*380) ≈ 7.6 A.

We see that for a consumer with a power of 5 kW, a 10 A circuit breaker is suitable.

What is the difference between W and V (V and A)

What is the difference between a volt and an ampere: Volt is a unit of measurement of voltage, and watt is a unit of power. V is the difference created in the electrical potential across a wire line when a current of 1A dissipates a unit of power, i.e. voltage. The definition of voltage is that it is the potential of electricity between different points. Along with this, it is used to indicate the difference in potential energy of an electric charge between points. An energy source is a voltage that represents expended or lost energy.

About power

Attention! Voltage is hypothetically similar to the pressure created in a circuit, pushing electrons through.

The passage of current must be ensured on two paths. This characteristic is considered the total energy for moving the charge. The definition of voltage is based on the fact that negative charges are attracted to high values, and positive charges to low values.

W – speed of work. The speed is maintained at 1 meter per second against a constant reaction force of 1 newton. If we consider it in relation to electromagnetism, the unit is the rate of work done when 1 ampere passes through a potential difference of 1V. Watt is a measure of power.

You may be interested in: Features of tantalum capacitors

Power

Power is the energy flow with which energy is consumed. It happens that in the description of a device it appears instead of kW - kVA. To determine this value, you need to know what is measured in kVA.

No energy is expended to complete the work, but on the contrary:

One of the factions becomes active, that is, it performs work or transforms into another form.
The other faction is reactive. The energy is directed into an electromagnetic field.

Attention! These quantities are different, despite the same proportionality. To avoid confusion, the indicator is measured not in watts, but in volt-amperes.

Mechanical power

Examples in nature and technology[ | ]

Magnitude	Description
10−9 watt	Radiation with a power of approximately 1 W falls on an area of the Earth's surface with an area of 1 m² from a star with a brightness of +1.4 magnitude.
5⋅10−3 watt	The radiation of conventional laser pointers has this power (or close to it), which is relatively safe for human vision.
1 watt	Approximate transmitter power of a typical mobile phone.
1⋅103 watt	Small heater. The approximate power of radiation incident on 1 m2 of the Earth's surface from the Sun at its zenith. Average annual power consumed by a single US household (average energy consumption - approximately 8900 kWh/year).
6⋅104 watts	A passenger car with an 80 horsepower engine.
1.2⋅107 watts	Electric train Eurostar.
8,212⋅109 watts	Power at peak loads of the world's largest nuclear power plant, Kashiwazaki-Kariwa (Kashiwazaki, Japan).
2.24⋅1010 watts	Design capacity of the world's largest hydroelectric power station "Three Gorges" (Sanxia, China).
1012 watts	Peak power of an average lightning strike.
1.9⋅1012 watts	Average estimated electrical power consumed by humanity in 2007.
1.5⋅1015 watt	Record power of pulsed laser radiation achieved at the Nova installation in 1999. The pulse energy was 660 J, the pulse duration was 440⋅10−15 s.
1.74⋅1017 watts	Based on the average irradiance on the Earth's surface of 1.366 kW/m², the total flux of solar radiation on the Earth's surface is approximately 174 PW. If the Earth did not re-radiate this energy into space, it would become more massive by 1.94 kg every second.
3.828⋅1026 watts	Scientists estimate the total radiation power of the Sun to be 382.8 W, which is more than two billion times more than the power of radiation incident on the surface of the Earth. In other words, due to thermonuclear reactions in the center of the Sun, our star loses mass in the amount of 4,260,000 tons every second.

What voltage is measured in volts and watts

Voltage in watts or volts is measured according to individual criteria. Voltage measurements are carried out in Volts, and in the drawings it is indicated by the letter V. The voltage is measured by a device - a voltmeter. The latest devices may be:

Analog.
Digital.

The first ones are more accurate.

Portable devices have voltmeters built into them, and these tools are used by electricians. Analog devices are installed on electrical panels: switchboards and generators. The latest equipment comes complete with digital meters.

The voltage value in accordance with international standards is established:

Kilovolt – kV.
Millivolt – mV.
Volt - V.
Megavolt - MV.
Microvolt - µV.

Voltage measurements
Important! Power is measured in watts (kilowatts). This value is directly proportional to the voltage, as well as to the magnitude of the current. The main difference is the designation of established indicators, according to the measurement system.

Unit conversion rules

In the instructions for many devices there are designations in volt-amperes. Their distinction is necessary only for specialists for whom these nuances are important professionally, but for ordinary consumers this is not so important, because the designations used in this case characterize almost the same thing. As for kilowatt/hour and just kilowatt, these are two different quantities that should not be confused under any circumstances.

To determine electrical power through the network current indicator, you can use various tools with which measurements and calculations are made:

using a tester;
using clamp meters;
making calculations on a calculator;
using special reference books.

Using a tester, we measure the voltage in the electrical network we are interested in, and then use a current clamp to determine the current strength. Having obtained the necessary indicators and applying the existing formula for calculating direct and alternating current, you can calculate the power. We divide the existing result in watts by 1000 and get the number of kilowatts.

Single phase electrical circuit

Basically, all household electrical networks are single-phase networks that use a voltage of 220 volts. The load marking for them is written in kilowatts, and the current strength is in amperes and is designated as AB.

To convert one unit to another, the formula of Ohm's law is used, which states that power (P) is equal to current (I) multiplied by voltage (U). That is, the calculation will look like this:

W = 1A x 1V

In practice, such a calculation can be applied, for example, to the designations on old electricity meters, where the installed machine is designed for 12 A. Substituting digital values into the existing formula, we get:

12A x 220V = 2640 W = 2.6 kW

Calculations for an electrical network with direct and alternating current are practically no different, but are valid only in the presence of active devices that consume energy, for example, incandescent electric lamps. And when devices with a capacitive load are connected to the network, then a phase shift appears between current and voltage, which is the power factor, written as cos φ. When there is only an active load, this parameter is usually equal to 1, but when there is a reactive load in the network, it must be taken into account.

In cases where the network load is mixed, the value of this parameter fluctuates around 0.85. Reducing the reactive component of power leads to a reduction in losses in the network, which increases the power factor. Many manufacturers, when marking a device, indicate this parameter on the label.

Three-phase electrical network

If we take the example of a three-phase network, then everything is somewhat different here, since three phases are involved. When making calculations, you need to take the value of the electric current of one of the phases, which is multiplied by the voltage in this phase, after which the resulting result is multiplied by cos φ, that is, by the phase shift.

Having thus counted the voltage in each phase, we add up the results and obtain the total power of the device, which is connected to a three-phase network. In formulas it looks like this:

Watt = √3 Ampere x Volt or P = √3 x U x I

Ampere = √3 Volt or I = P/√3 x U

It must be borne in mind that there is a difference between phase and line voltage and current. But the calculation formula remains the same, except for the case when the connection is made in the form of a triangle, and it is necessary to calculate the load of an individual connection.

For circuits with alternating current, there is an unspoken rule for this calculation: the current strength is divided in half to select the power of the protective and starting relays. The same rule applies when calculating the diameter of the conductor in such electrical circuits.

How to convert volts and watts and vice versa

To correctly complete the task associated with converting volts to watts, you can follow the following algorithm:

You need to find the power value in the operating manual of the electrical appliance. Companies often indicate this value in volt-amperes. This symbol indicates the maximum amount of electricity consumed. So it is equal to the power value.
Determine the efficiency of the power source based on the design features and the number of devices connected to it. As a rule, this coefficient is set in the range from 0.6 to 0.8.
Convert current-voltage indicators to W: find out the active power of energy equipment designed to supply uninterruptible power.

What is "volt-ampere"

Important! Sometimes VA is mistakenly equated to total power or treated as a unit absolutely equivalent to a watt. This is an error associated with the identification of a certain quantity and its dimension.

Having figured out what VA is, you need to consider what needs to be done if you need to convert volt amperes to watts. To solve everyday problems, you can follow the following algorithm:

In the power supply instructions you need to find the value of the power it consumes. Often manufacturing companies indicate the value of this parameter in volt-amperes. It indicates the largest amount of electrical energy that the device is capable of consuming from the network. Thus, it can be equated to the full power value.
Now you need to find out the efficiency of the source being used. It is determined by the features of its design and how many devices are connected to it. In practice, this coefficient when connecting household and professional appliances usually varies between 0.6-0.8.
After this, the actual conversion of volt-ampere units to watt units is performed. To perform this, you need to find out the active power of the device that supplies uninterruptible power. To find out its value in watts, you need to multiply the consumed power parameter in volt-amperes, indicated by the manufacturer in the accompanying documentation, by the efficiency of the device (also known as power factor). This can be expressed using the formula: B = VA*efficiency.

A calculator is also used to convert va to tu. You need to fill in the fields that the screen form offers with values corresponding to the indicators of a particular device, and click the button that initiates calculations. Upon completion, the user will receive the desired power value in watts.

Expert opinion

It-Technology, Electrical power and electronics specialist

Ask questions to the “Specialist for modernization of energy generation systems”

How to convert volt-amperes to watts - power calculator Remember that for high-voltage networks, the indicated current differs depending on the efficiency. Ask, I'm in touch!

What is power Watt [W]

Power is a quantity that determines the ratio of work performed by a current source over a certain period of time. One watt corresponds to the product of one ampere and one volt, but when determining energy costs, the value of kilowatt/hour .

It corresponds to the consumption of one thousand watts for 60 minutes of operation. It is by this indicator that the cost of electricity services is determined.

In most cases, the power consumed by the device is indicated in the technical documentation or on the packaging. The specified quantity is produced in one hour of work.

For example, a computer with a 500 W power supply will spin 1 kW for 2 hours of operation.

To help determine the current strength at a known power, a calculator will help, which converts one physical quantity to another.

Calculation

Special formulas are used to calculate values. After counting them, all that remains is to insert them into the above formulas. To find the electric current, you need to divide the voltage by the conductor resistance, and to find the power, you need to multiply the voltage by the current force or double the current value by the resistance. It is also possible to divide the double voltage value by the resistance.

Note! Often all the necessary data is written on the box or technical specifications on the manufacturer’s website. Often the information is indicated in kW and can easily be converted into amperage using a converter. Another simple option for determining energy consumption and amperage is to study the consumer's electric meter or circuit breaker

But in this case, you only need to connect one device to the network

Another easy way to determine energy consumption and amperage is to examine the consumer's electric meter or circuit breaker. But in this case, it is necessary to connect only one device to the network.

Calculation formula

What is Current Strength. Ampere [A]

Current is the speed at which electrical charge flows through a conductor. One ampere is equal to a charge of one coulomb that passes through a conductor in one second. One coulomb represents a very large charge, so in most devices this value is measured in milliamps.

The current strength depends on the cross-section of the conductor and its length. This must be taken into account when planning structures, as well as choosing electrical appliances. Although most should not think about this, since this is the task of engineers and designers.

How many watts are in 1 ampere?

To determine the power of a circuit, the concept of voltage is also important. This is the electromotive force that moves electrons. It is measured in volts. Most devices have this characteristic in their documentation.

To determine the power at a current of one ampere, you need to know the network voltage. So, for a 220 volt outlet it will be: P = 1 * 220 = 220 W. Formula for calculation: P = I*U, where I is current and U is voltage. In a three-phase network, a correction factor must be taken into account, reflecting the percentage of operating efficiency. In most cases it is between 0.67 and 0.95.

Tables of ratios of amperes, volts, watts, ohms

To simplify, the main parameters of the electrical circuit are explained using the example of the functioning of a conventional pipeline. The movement of fluid is ensured by the pressure difference. The narrowing (expansion) of the transport route changes the flow resistance accordingly. If necessary, using the listed parameters or experimentally, you can set the pipeline productivity in liters per unit of time.

By analogy with the above description, the potential difference (voltage) ensures the movement of electric charges (current). As the cross-section of the conductor decreases, the electrical resistance increases. Knowing the basic parameters, it is easy to calculate the power consumption of the connected load.

Table for calculating the comfort zone of “electronic” cigarettes

The specified power data corresponds to certain resistance and voltage values. Similar tables are compiled for converting Watts into amperes and other quantities. This example clearly demonstrates the main disadvantages of the tabular form:

complexity of processing large amounts of data;
discreteness of information provision;
limited accuracy.

Graphical representation of basic formulas for calculating electrical parameters

Using calculations, you can convert volts to amperes quickly and accurately.

For your information. As an alternative, an electrical quantity converter is used, which is available for free use on reference and specialized websites on the Internet.

Ampere – Watt conversion table

To convert watts to amperes, you need to use the previous formula, expanding it. To calculate the current, you need to divide the power by the voltage: I = P/U. The following table shows the amperage for devices with different voltages - 6, 12, 24, 220 and 380 volts.

Remember that for high voltage networks, the specified amperage differs depending on the efficiency.

Table of the ratio of amperes and watts, depending on voltage.

6V	12V	24V	220V	380V
5 W	0.83A	0.42A	0.21A	0.02A	0.008A
6 W	1.00A	0.5A	0.25A	0.03A	0.009A
7 W	1.17A	0.58A	0.29A	0.03A	0.01A
8 W	1.33A	0.66A	0.33A	0.04A	0.01A
9 W	1.5A	0.75A	0.38A	0.04A	0.01A
10 W	1.66A	0.84A	0.42A	0.05A	0.015A
20 W	3.34A	1.68A	0.83A	0.09A	0.03A
30 W	5.00A	2.5A	1.25A	0.14A	0.045A
40 W	6.67A	3.33A	1.67A	0.13A	0.06A
50 W	8.33A	4.17A	2.03A	0.23A	0.076A
60 W	10.00A	5.00A	2.50A	0.27A	0.09A
70 W	11.67A	5.83A	2.92A	0.32A	0.1A
80 W	13.33A	6.67A	3.33A	0.36A	0.12A
90 W	15.00A	7.50A	3.75A	0.41A	0.14A
100 W	16.67A	3.33A	4.17A	0.45A	0.15A
200 W	33.33A	16.66A	8.33A	0.91A	0.3A
300 W	50.00A	25.00A	12.50A	1.36A	0.46A
400 W	66.66A	33.33A	16.7A	1.82A	0.6A
500 W	83.34A	41.67A	20.83A	2.27A	0.76A
600 W	100.00A	50.00A	25.00A	2.73A	0.91A
700 W	116.67A	58.34A	29.17A	3.18A	1.06A
800 W	133.33A	66.68A	33.33A	3.64A	1.22A
900 W	150.00A	75.00A	37.50A	4.09A	1.37A
1000 W	166.67A	83.33A	41.67A	4.55A	1.52A

Using the table it is also easy to determine the power if the voltage and current are known. This is useful not only for calculating energy consumption, but also for choosing special equipment responsible for uninterrupted operation or preventing overheating.

Formula for single-phase network

In electrical engineering there is such a concept as active and reactive load. The reactive load is characterized by the consumption of reactive power and is expressed by the coefficient cos(φ) (cosine “phi”). Taking into account the cos(φ) coefficient, the formula by which you can convert Amps to Watts will look like:

In apartment sockets the voltage is not constant, but alternating. In such networks, in addition to active power, there is reactive power. It appears when there is an inductive or capacitive load. The sum of these powers is called total. The parameter that determines the active load component is called cosφ (cosine phi).

Reference! Electrical devices that consume inductive power are electric motors and transformers. Capacitive loads are found only in electronic circuits and power factor compensators.

In order to find out how many watts are in an ampere, the calculation must be made using the following formulas - P=U*I*cosφ, and the current, accordingly, I=P/(U*cosφ). In everyday life, cosine phi is usually not taken into account.

For “household loads” cos(φ) is equal to one – cos(φ) = 1.

It is also not used when calculating devices that consume only active power - electric heating, electric furnace with heating elements, water heater, electric kettle, electric stoves, incandescent lamps and other similar devices.

To understand how to convert Amps to Watts using the formula, you can consider an example:

11.36 Amps = 2500W/220V
6.81 Amps = 1500W/220V
4.54 Amps = 1000W/220V
2.27 Amps = 500W/220V
1.81 Ampere = 400W/220V
1 Ampere = 220W/220V
0.45 Ampere = 100W/220V
0.27 Ampere = 60W/220V

If we take a 12-volt car battery as an example, a load of 1 ampere will correspond to a power of 12 watts. For a household network with a voltage of 220 Volts, a current of 12 Amps corresponds to 2640 Watts or 2.64 kW.

How to use

To convert current into power, it is enough to enter the nominal voltage and indicate the second known value. The calculator will automatically calculate the unknown indicator and display the result.

You can find out the voltage and standard current in the technical documentation of the device. For household appliances, the power is usually indicated, from which the current is also easy to calculate. For convenience, in the calculator you can switch watts to kilowatts, and amperes to milliamps.

Read further:

Calculation of electrical power during repair and design

Car engine power calculator

Kilowatt to horsepower conversion calculator

Calculator for converting pressure in bar to pressure in megapascals, kilograms of force, pound of force and atmospheres

Battery discharge time calculator

Online calculator for calculating battery charging time (with direct current), how long to charge the battery

Conversions from amps to kilowatts and vice versa

You can convert values in three ways: a universal table, an online calculator or a formula. As for using the calculator, you need to insert the initial indicators into the appropriate fields and press the button. It is convenient to use this system when you have to deal with large digital values.

Note! According to the universal table and formula, you can find out that one A contains 0.22 kW or 0.38 kW. You can convert values using the available numbers using a calculator or by multiplying by the given value. For example, to calculate how much 6A will be in kW, you need to multiply 0.6 by 0.22. The result will be 1.32 kW.

In a single-phase electrical circuit

To calculate the required values in a single-phase network, where the rated current of the circuit breaker, for example, is 10 A and in normal condition no energy flows through it above the specified value, it is necessary to calculate the maximum electrical power. You need to substitute the values of voltage and electric current into the formula for finding power and multiply them together. It turns out that the power will be equal to 220*10=2200 watts. To convert to smaller values, you need to divide the figure by 1000. The result is 5.5 kW. This is the entire amount of power supplied from the machine.

Translation in a single-phase electrical circuit

In a three-phase electrical circuit

The conversion of indicators in a three-phase network designed for 380 volts can be done in a similar way. The difference lies in the formula. To determine the required data, you need to substitute the root of three into the product of voltage and electric current. For example, the machine is designed for 40 A. By substituting the values, you can get 26327 W. After dividing the value by 1000, the result is 26.3 kW. That is, it turns out that the machine will be able to withstand the load.

With a known power indicator of a three-phase circuit, the operating current can be calculated by transforming this formula. That is, the electrical power must be divided by the root of 3 multiplied by the voltage. As a result, if the electrical power is 10 kW, the value of the machine will be 16A.

Translation in a three-phase electrical circuit

Voltage

Let's consider the first and defining quantity - voltage, which is measured in volts. Letter abbreviation: В (Russian designation) or V (English designation). In formulas, voltage is denoted by the letter U (usually a capital letter). Essentially, the magnitude of the voltage is the potential difference between the two poles of the source. All you need to understand at this stage is that without tension you will not get a single physical quantity that is discussed in this article (except for resistance, and even then not always). The voltage can be constant, variable (various forms), pulsating, randomly changing, etc. Later I will write articles about constant and alternating voltage and insert links here.

What is voltage - Volt [V]

Voltage indicates the potential ability of electricity to do useful work (measured in Volts or V). The higher it is, the less current is required for the same power, which has a beneficial effect on the thickness and mass of copper in the supply wires. After all, they are heated by passing current, and this is an unproductive loss, so the main electricity transmission lines operate under very high voltage.

In cars, for safety reasons, as well as by tradition, a voltage of 12 volts is used. In heavy trucks, where consumption is high, the voltage is raised to 24 volts, and electric vehicles, with their powerful traction motors, are powered by their batteries with a voltage of 400 volts and above. It's dangerous, but there's no other way out.

Current and resistance. Dependence of current on resistance

These are two more physical electrical quantities. Current is measured in amperes. Letter abbreviation: A (spelled the same in Russian and English). In formulas, current is denoted by the letter I (also most often a capital letter). Resistance is measured in ohms. Letter abbreviations: Ohm (Russian designation), Ohm (English designation) and Ω (universal international designation). This is where a little difficulty begins. The current strength directly depends on the voltage and resistance. I won't go into detail here. To do this, I recommend reading the article about Ohm’s law. If you don't know him yet, it's advisable to do so before you start reading further.

Single-phase network

In private homes, the voltage does not exceed 220 volts. In this case, you need to make calculations specifically for a single-phase network. General physical formula for voltage: U = P/I, where:

U is voltage;
P - electrical power;
I is the current strength.

The result makes it possible to measure consumption in watts, but usually a value such as kilowatt is used. To do this, you need to divide the resulting number by 1000 (1 kW = 1000 W). You can understand the algorithm for calculating how many amperes are in 1 kilowatt using an example.

If in a single-phase network the consumption is 220 V, then the rating of the automatic device is calculated as follows: 220/200 = 1 ampere. If all devices use a total power of 0.13 kW, then you will need an automatic machine with 6 amperes (0.13/220 = 6 A). That is, now you can find out how many amperes are contained in kW: 1000/220 = 4.5 A.

Reverse calculations can be done in a similar way. If the network has a 5 A disconnect device, then you can determine the maximum power it can handle. In this case, amperes are multiplied by volts: 5x220 = 115 W. If the devices consume more power, then the machine will not be able to withstand it, it must be replaced with another. You can use the table for converting amperes to watts and kilowatts:

2 A = 0.4 and 1.3 kW for single- and three-phase networks, respectively;
6 amperes are 1.3 and 3.9 kilowatts;
10 A = 2.2 and 6.6 kW;
16 A - 3.5 kW for single-phase and 10.5 for a network with a voltage of 380 V;
20 amperes = 4.4 and 13.2 kilowatts;
25 A - 5.5 and 16.4 kW.

Power calculation by current and voltage

Finally we come to the concept of electrical power. Measured in watts. Letter abbreviation: W (Russian designation), W (English designation). In formulas, active power is denoted by the letter P (always capital English). Power is the product of current and voltage. But since the voltage can be constant or alternating, and the resistance that gives the current in a closed circuit under voltage can be active and/or reactive, power is divided into three types:

active (already mentioned)
reactive. This is the sum of the inductive and capacitive components of the total power. Measured in VAR. Letter abbreviation: var (Russian designation) and var (English designation). In formulas it is denoted by the letter Q (always a capital English letter).
complete. Power taking into account active and reactive power. It is measured in volt-amperes. Letter abbreviation: V•A or VA (Russian designation) and V•A or VA (English designation). In formulas it is denoted by the letter S, and the letter Z (always a capital English letter) is found.

Let's take a closer look at each type of power.

Watt to A calculator (3 phase, alternating current, phase voltage)

Formula for converting W to A

The current I in amperes (A) of a three-phase phase-to-phase network is equal to the power P in watts (W) divided by three times the product of the power factor PF and the voltage U in volts (V).

Sources

https://odinelectric.ru/knowledgebase/kak-perevesti-ampery-v-vatty-i-obratno
https://rusenergetics.ru/polezno-znat/ampery-v-vatty
https://www.liderteh.ru/chastye_voprosy/chto-takoe-kva-kvt
https://rusenergetics.ru/polezno-znat/kak-vyschitat-ampery-znaya-moschnost-i-napryazhenie
https://etlib.ru/calc/amps-watts-conversion
https://www.calc.ru/voltamper-v-vatt.html
https://MicroExcel.ru/watt-to-amper/

Circuit active power

As you already understand, power can be calculated only when voltage is applied to the circuit and current flows through it. Consequently, the circuit elements set the value of the current, including its parameters such as active and reactive current. In constant voltage circuits there is only active current and now you will understand why. Active and reactive current is formed due to active or reactive resistance. In simple words: the value of active (or more correctly called linear) resistance does not change depending on the frequency or polarity of the voltage. That is, if we have 10 ohms of linear resistance, then no matter what voltage we apply (positive, negative, constant, alternating, etc.), the resistance to electric current will always be 10 ohms. A simple example: an incandescent lamp, an electric stove, a heating element, a resistor, etc. Well, when we apply a constant voltage to a nonlinear voltage, then depending on the type of voltage, the resistance will be either infinitely large (like a capacitor) or only active. Now I will consider reactive power and you will finally understand everything.

It comes in two types: capacitive and inductive or mixed (also known as total reactive power).

Capacitance AC resistance

Capacitive current is created by capacitors. The capacitance formula that you see on the left indicates a certain value ω, which was introduced to shorten the formula “2π•f”, where π is the number Pi, and f is the network frequency. Therefore, if the network frequency is zero (constant voltage), Xc tends to infinity, and an infinitely large resistance, according to Ohm's law, creates an infinitesimal current.

AC inductance resistance

Inductive reactance is created by coils, transformers and everything that has inductance. The formula you see on the left also has the value ω. Therefore, when the grid frequency is zero, XL is also zero.

Apparent reactive power

Mathematically it looks like the difference between inductive and capacitive reactance, and geometrically it is the sum of two vectors. The fact is that in inductance the current leads the voltage, and in the capacitance the current lags behind the voltage by an angle of 90°. For example, for a container, geometrically it looks like this:

Thus, there is purely capacitive or purely inductive reactance and there is mixed resistance, which is calculated using the formula given above.

What are the amps and watts associated with it?

Volts = Current (amps) x Resistance (ohms) Watts = Volts x Current x PowerFactor

What is the definition of amperes and watts?

Definition of ampere: "This constant current, if maintained in two straight parallel conductors of infinite length and negligible cross-sectional area and placed one meter part in a vacuum, will produce between them a force equal to 2 pix 10^-7 newtons per unit length."

How do Watts relate to Ohms?

ohms is a measure of resistance (R) in a circuit. Watts is a measure of power (P), in this case suggesting that it is the power used by a resistive element (lamp, heater, etc.). Power (W) = Current (Amps) x Current (Amps) x Resistance (Ohms) or Resistance (Ohms) = Power (W) / (Current x Current)

How do you convert volt-amps to watts?

How to calculate amperes if there are no watts?

Answer.V = R * I and W = V * I. so. W = R * I * I. Example: 10V = 2R * 5A. 10V * 5A = 50 W. 2R * 5A * 5A = 50 W

What kind of lighting do you prefer?

Built-in Chandelier

Difference between watt and volt-amperes?

If you have 500 watts and 240V, what are the amps?

The equation to use is I = W/E. Ampere = Watt/Volt. Amps = 500/240 = 2.08 amps.

What is meant by volts and ohms?

Full circuit power

Now you can find out the total power of the circuit. If you remember geometry, then the words will pop up in your memory: the square of the hypotenuse is equal to the sum of the squares of the legs. For calculating total power, this statement is also true.

or or

Current power factor

There is also a formula for total power through power factor. Cos φ is a dimensionless quantity. This is the geometric ratio of active and reactive power. For linear resistance or constant voltage, cos φ is equal to unity.

Using formulas in a certain way, you can calculate power not only through current and voltage. For this, there is a mnemonic diagram, where the desired value can be obtained through two other known values.

Calculators for converting watts to amperes and vice versa

Despite the rather simple formulas and even the available conversion factors, it is still easier for many users to carry out such transformation of quantities using calculators. Well, let's give them that opportunity.

Below are two calculators - for converting current into load and vice versa. In order not to split into various nuances, both calculators are made universal, that is, they can be used for direct current networks, single-phase and three-phase alternating current, for devices with and without reactive loads.

If you do not specify the power factor (Cos φ) in the last input field, then it is assumed to be equal to one, that is, there is no reactive power by default.

The user selects and indicates everything independently in the appropriate fields of the application - and then by pressing the “CALCULATE …” button, displays the finished result. Fast and accurate!

Relationship between power and current in a three-phase network

The principle of calculating power and current for three-phase networks remains the same. The main difference is a slight modernization of the calculation formulas, which allows us to fully take into account the design features of this type of wiring.

The following expression is traditionally taken as a basic relationship:

W =1.73* U*I, (4)

and U in this case represents the linear voltage, i.e. is U = 380 V.

From expression (4) follows the advantage of using three-phase networks in justified cases: with such a wiring diagram, the current load on individual wires drops to the root of three times with a simultaneous threefold increase in the power supplied to the load.

To prove the last fact, it is enough to note that 380/220 = 1.73, and taking into account the first numerical coefficient we get 1.73 * 1.73 = 3.

The above rules for the connection of currents and power for a three-phase network are formulated in the following form:

one kW corresponds to 1.5 A of current consumption;
one ampere corresponds to a power of 0.66 kW.

Let us point out that everything that has been said is true in relation to the case of connecting the load with a so-called star, which is most often encountered in practice.

A triangle connection is also possible, which changes the calculation rules, but it is quite rare and in this situation it is advisable to contact a specialist.

What is the difference between ampere and kilowatt

The fundamental difference between the units of measurement of electrical network parameters, which are included in the title of this section, is that they represent a numerical measure of various physical quantities.

In this case:

amperes (abbreviation A) show current strength;
watts and kilowatts (abbreviation W and kW, respectively) characterize active (actually useful) power.

In practice, an expanded description of power is also used, measuring it in volt-amperes and, accordingly, kilovolt-amperes, which are briefly referred to as VA and kVA.

They, unlike W and kW, which describe active power, indicate total power.

In DC circuits, the apparent and active powers are the same. Similarly, in an AC network, with a small load power, at the engineering level of rigor, the difference between W (kW) and VA (kVA) can be ignored, i.e. work only with the first two units.

For such circuits the following simple relation applies:

W = U*I, (1)

where W is the (active) power specified in W, U is the voltage specified in volts, I is the current measured in amperes.

When the load power increases to a level of a thousand watts and above for direct current, relation (1) does not change, but for alternating current it is advisable to write it as:

W = U*I*cosφ, (2)

where cosφ is the so-called power factor or simply “cosine phi”, showing the efficiency of converting electric current into active power.

In physical meaning, φ represents the angle between the vectors of alternating current and voltage or the phase shift angle between voltage and current.

A good criterion for the need to take this feature into account are those cases when VA or kVA are indicated instead of kW in the nameplate data and/or on the body nameplates of electrical appliances, mainly powerful ones with a consumption of more than 1 kW.

Typically, for household electrical devices with powerful electric motors (washing machines, dishwashers, pumps and the like) you can set cosφ = 0.85.

This means that 85% of the energy consumed is useful, and 15% forms the so-called reactive power, which continuously transfers from the network to the load and back again until it is dissipated in the form of heat during these transitions.

At the same time, the network itself must be designed specifically for full power, and not for useful power. To indicate this fact, it is indicated not in watts, but in volt-amperes.

As a unit of measurement, the watt (volt-ampere) is sometimes too small, resulting in numbers that are difficult to visually perceive with many digits. Taking this feature into account, in some cases power is indicated in kilowatts and kilovolt-amperes.

For these units the following is true:

1000 W = 1 kW and 1000 VA = 1 kVA. (3).