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 on sockets or circuit breakers through which devices are connected to the network, it is customary to indicate the current strength in amperes. To understand whether the socket will withstand the connected device, you need to know how to convert amps to watts.
Power units
Converting watts to amperes and vice versa is a relative concept, because these are different units of measurement. Amps are the physical quantity of electric current, that is, the speed at which electricity passes through a cable. Watt - the amount of electrical power, or the rate of consumption of electricity. But such a translation is necessary in order to calculate whether the value of the current strength corresponds to the value of its power.
Converting amperes to watts and kilowatts
Knowing how to calculate the correspondence between ampere and watts is necessary in order to determine which device can withstand the power of connected consumers. Such devices include protective equipment or switching.
Before choosing which circuit breaker or residual current device (RCD) to install, you need to calculate the power consumption of all connected devices (iron, lamps, washing machine, computer, etc.). Or vice versa, knowing what kind of machine or protective shutdown device is worth, determine which equipment will withstand the load and which will not.
To convert an ampere to kilowatts and vice versa, there is a formula: I \u003d P / U, where I are amperes, P are watts, U are volts. Volts are the mains voltage. In residential premises, a single-phase network is used - 220 V. In production, an electric three-phase network is used to connect industrial equipment, the value of which is 380 V. Based on this formula, knowing the amperes, you can calculate the correspondence to watts and vice versa - convert watts to amperes.
Situation: There is a circuit breaker. Technical parameters: rated current 25 A, 1-pole. It is necessary to calculate what wattage of devices the machine can withstand.
The easiest way is to enter the technical data into the calculator and calculate the power. And you can also use the formula I \u003d P / U, it turns out: 25 A \u003d x W / 220 V.
x W=5500 W.
To convert watts to kilowatts, you need to know the following measures of power in watts:
- 1000 W = 1 kW,
- 1000,000 W = 1000 kW = MW,
- 1000,000,000 W = 1000 MW = 1,000,000 kW, etc.
So, 5500 W \u003d 5.5 kW. Answer: an automatic machine with a rated current of 25 A can withstand the load of all devices with a total power of 5.5 kW, no more.
Apply a formula with voltage and current data in order to select the type of cable in terms of power and current. The table shows the correspondence of the current to the wire section:
| Conductor cross section, mm² | Copper conductors of wires, cables | |||
|---|---|---|---|---|
| Voltage 220 V | Voltage 380 V | |||
| Current, A | power, kWt | Current, A | power, kWt | |
| 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
You need to convert watts to amperes in a situation where you need to install a protective device and you need to choose what rated current it should be. It is clear from the operating instructions how many watts a household appliance consumes when connected to a single-phase network.
The task is to calculate how many amperes in watts or which socket corresponds to the connection if the microwave oven consumes 1.5 kW. For the convenience of calculating kilowatts, it is better to convert to watts: 1.5 kW = 1500 watts. We substitute the values in the formula and get: 1500 W / 220 V \u003d 6.81 A. We round the values up and get 1500 W in terms of amperes - the microwave current consumption is at least 7 A.
If you connect several devices at the same time to one protection device, then in order to calculate how many amperes in watts, you need to add all the consumption values \u200b\u200btogether. For example, the room uses lighting with 10 LED lamps. 6 W each, a 2 kW iron and a 30 W TV. First, all indicators must be converted to watts, it turns out:
- lamps 6*10= 60 W,
- iron 2 kW=2000 W,
- TV 30 W.
60+2000+30=2090 W.
Now you can convert amperes to watts, for this we substitute the values \u200b\u200binto the formula 2090/220 V \u003d 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 the correspondence between the rate of electricity consumption and the current strength for single-phase and three-phase networks.
| Ampere (A) | Power, kWt) | |
| 220 V | 380 V | |
| 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 |
