You will need
  • technical passports for all energy consumers;
  • calculator.
The easiest way to find the power consumption – fold consumption of all electrical appliances in the house. To find these figures in the Datasheet of the device.
You need to consider the features of inrush currents that occur when starting the operation of the energy consuming entity. These indicators can exceed the average values stated in the passport. Consumers of electricity with inductive and active resistance, in which the energy is spent on heating – plates, irons, incandescent lamps have the same operating voltage and at the time of launch, therefore, when calculating the total power of their indicators are simply summed.
Objects with a condenser (capacitive) impedance, which is part of the energy is converted into heat, and the other part to generate a magnetic field, may when you start to consume much more energy than in a normal working condition. Therefore, before calculating the total consumption, you must measure each object to multiply by 2.5-3 to avoid overloading the system.
Use to calculate the energy consumed by the following formula:

PE = 1,1* (K1 * НМЭ1 * пуск1+ K2 * НМЭ2 * пуск2+ ...), where PE is the total power of K – the number one type of energy consuming device, NME – rated power of the device To start – coefficient in-rush current.
The calculation steps are the following:

- determine by the data sheet rated power of all appliances;
- calculate the power rating of the device with a given voltage at the time of start;
- sum all received values;
- multiply the amount by 1.1 (i.e. add 10% for reserve stock to the energy source not work wear).
Example: the house has 5 sources of energy consumption: oven (NMA = 900 W), 2 incandescent bulbs (NMA = 2*100 W), refrigerator (NMA = 600 W) and TV (NMA = 500 watts). A fridge and TV are of capacitor resistance, so they need to adjust the ratio of starting current to 2.5.

Solution: according to the formula 1,1*(1*900*1 + 2*100*1 + 1*600*2,5 + 1*500*2,5), the total capacity of 4,235 kW. Accordingly, the power source must have a capacity of not less than 4.3 kW.
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