You will need
  • AC voltmeter, AC ammeter, wattmeter.
In some cases, the instantaneous power consumption of the appliance stated in his passport data. To get the value of their consumption of electricity over a certain period of time, multiply the instantaneous energy consumed (in kW) of the device to the value of the period of time during which he worked (in hours). For example, when calculating the energy consumption of household with a TV with a power consumption of 80 Watt, who has worked for 3.5 hours, multiply the capacity of the TV (0,08 kW) time (3.5 hours). Get the value of the total energy consumed by the TV during this time: 0,08 × 3,5 = 0.28 kilowatt-hours. In the case when you need to calculate the total consumed power of the group of devices, the consumed power is first calculated for each device, then these values are summed.
To measure the instantaneous power consumption of the device turn on the parallel plug of the instrument AC voltmeter, series - ammeter in AC. Turn on the device. Count and multiply the obtained values of voltage and current. For example, the resulting voltage was 218 Volts, and the current is 0.75 Ampere: 218 × 0,75 = 163,5 Watt. Multiply this value by the amount of time during which he worked (e.g. 6 hours) and get the value of the consumed power: 0,1635 × 6 = 0,981 per kilowatt-hour.
With the availability of modern household wattmeter plug it into an electrical outlet. Then connect the measured consumer current in the socket located on the housing of the power meter. Consider the value of the instantaneous energy consumption. On some models, the power meter further specify the value of energy consumed since the inclusion of time.