On household appliances (mixer, hair dryer, blender) manufacturers write the power consumption in watts, on devices that require large amounts of electrical load (electric stove, vacuum cleaner, water heater) - in kilowatts. And sockets or circuit breakers through which appliances are plugged in are usually marked with amperes. To understand if the outlet will hold the appliance to be plugged in, you need to know how to convert amps to watts.
Power Units
Translating watts into amps and vice versa is a relative concept because they are different units of measurement. Amperes are a physical measure of the strength of an electric current, that is, the rate at which electricity flows through a cable. Watt is a measure of electrical power, or the rate at which electricity is consumed. But this translation is necessary in order to calculate whether the value of current corresponds to the value of its power.
Converting amps to watts and kilowatts
Knowing how to calculate the correspondence of amps to watts is necessary in order to determine what device is able to withstand the power of connected consumers. Such devices include protective equipment or switching devices.
Before choosing which circuit breaker or residual current device (RCD) to install, you need to calculate the power consumption of all the appliances to be connected (iron, lamps, washing machine, computer, etc.). Or vice versa, knowing what the circuit breaker or circuit breaker is, determine which equipment will withstand the load and which will not.
To convert amps to kilowatts and vice versa, there is a formula: I=P/U, where I is amps, P is watts, U is volts. Volts are the mains voltage. In living quarters, a single-phase mains is used - 220 V. In manufacturing to connect industrial equipment, an electrical three-phase network, the value of which is 380 V. Based on this formula, knowing amperes, you can calculate the correspondence to watts and vice versa - to translate watts into amperes.
Situation: There is a circuit breaker. Technical parameters: rated current 25 A, 1-pole. You need to calculate what wattage devices can handle the circuit breaker.
The easiest way is to enter the technical data into a calculator and calculate the power. Or you can use the formula I=P/U, you get: 25A=xW/220V.
x W=5500 W.
To convert watts to kilowatts, you need to know the following measures of power in watts:
- 1,000 watts = 1 kW,
- 1,000,000 watts = 1,000 kW = MW,
- 1,000,000,000 watts = 1,000 MW = 1,000,000 kW, etc.
So 5,500 watts = 5.5 kW. Answer: a circuit breaker with a rated current of 25 A can handle the load of all appliances with a total capacity of 5.5 kW, not more.
Apply the formula with voltage and current data in order to select the type of cable according to the power and amperage. The table shows the amperage matching of the wire cross-section:
| Wire cross section, mm² | Copper conductors of wires, cables | |||
|---|---|---|---|---|
| Voltage 220 V | Voltage 380 V | |||
| Current, A | Power, kW | Current, A | Power, kW | |
| 1,5 | 19 | 4,1 | 16 | 10,5 |
| 2,5 | 27 | 5,9 | 25 | 16,5 |
| 4 | 38 | 8,3 | 30 | 19,8 |
| 6 | 46 | 10,1 | 40 | 26,4 |
| 10 | 70 | 15,4 | 50 | 33 |
| 16 | 85 | 18,7 | 75 | 49,5 |
| 25 | 115 | 25,3 | 90 | 59,4 |
| 35 | 135 | 29,7 | 115 | 75,9 |
| 50 | 175 | 38,5 | 145 | 95,7 |
| 70 | 215 | 47,3 | 180 | 118,8 |
| 95 | 260 | 57,2 | 220 | 145,2 |
| 120 | 300 | 66 | 260 | 171,6 |
How to convert Watt to Ampere
To convert watts to amperes is necessary in a situation where you need to put a protective device and need to choose what the current rating should be. It is clear from the instruction manual how many watts are consumed by a household appliance connected to a single-phase network.
The task is to calculate how many amperes in watts or what corresponds to the socket for connection, if the microwave consumes 1.5 kW. For ease of calculation, it is better to translate kilowatts into watts: 1.5 kW = 1500 watts. Substitute the values in the formula and we get: 1500 W / 220 V = 6,81 A. Rounding up the values we get 1500 W in terms of amperes - UHF current consumption is not less than 7 A.
If you connect several appliances at the same time to one protection device, you need to add all the consumption values together to calculate how many amperes in watts. For example, in a room you use lighting with 10 LED lamps of 6 watts each, an iron of 2 kW and a TV of 30 watts. First, all the values must be converted to watts, you get:
- 6*10= 60 watts bulbs,
- a 2 kW iron = 2,000 watts,
- the TV set 30 watts.
60+2000+30=2090 watts.
Now you can convert amps to watts, to do this, substitute the values in the formula 2090/220 V = 9.5 A ~ 10 A. Answer: the current consumption is about 10 A.
You need to know how to convert amps to watts without a calculator. The table shows how the rate of electricity consumption corresponds to the amperage on a single-phase and three-phase grid.
| Ampere (A) | Power (kW) | |
| 220 В | 380 В | |
| 2 | 0,4 | 1,3 |
| 6 | 1,3 | 3,9 |
| 10 | 2,2 | 6,6 |
| 16 | 3,5 | 10,5 |
| 20 | 4,4 | 13,2 |
| 25 | 5,5 | 16,4 |
| 32 | 7,0 | 21,1 |
| 40 | 8,8 | 26,3 |
| 50 | 11,0 | 32,9 |
| 63 | 13,9 | 41,4 |
