A lot depends on such a parameter as the power consumption. After all, these are electric currents that are acceptable in everyday life, and, ultimately, electricity bills. The correctly calculated load depends on the mode of operation of the entire electrical network, so that in the event of an overvoltage it is not necessary to repair the power cable or power transformer or to change fusible inserts and reset the protections. When buying a household appliance, pay attention to its power consumption and compare it with the maximum permissible load in your apartment or private house.
First we will measure the supply cable. Usually an aluminum wire with a cross section of four square millimeters is laid on the apartment. The circuit-breaker in this case is set with an emergency shutdown setting of 16-20 amps. This means that when the rated current is exceeded, the power supply will be disconnected after a while. This triggers a thermal relay that monitors energy consumption. Also in the switch there is a cut-off relay, which will work if the rated current is exceeded by 10 or more times. It is high-speed and is designed to protect your wiring from inrush currents or to instantly disconnect from the main network in the event of a short circuit.
Based on this, it is possible to make a preliminary calculation, where the maximum power consumption will be determined, at which it is possible to safely operate electrical wiring. At a voltage of 220 volts it is only 4-5 kW. This, of course, is not enough to heat the apartment with electric heaters in the cold period, but it is enough for the stable operation of basic household appliances. You can use, for example, at the same time an iron, a heater, a refrigerator, a TV and lighting fixtures. But if at the same time you turn on the electric kettle and start using the boiler, the total power consumption will exceed the permissible - and soon the shutdown will occur.
It is necessary to know the division of all electrical appliances for the presence and absence of starting currents. Thus, heating and lighting devices, a computer, a television set and all electronics in the house do not create an additional load on the mains. The power consumption of the computer is thus constant. A very different picture can be observed when switching on electrical appliances, which include asynchronous electric motors. This, for example, refrigerators, air conditioners, electric drill. When such devices are switched on, significant starting currents arise which exceed the rated currents of the device by 14 or more times. Simultaneous switch-on of these units will lead to a power failure.
A slightly different meaning is the power consumption of the laptop or any other device equipped with a personal power source. In this case, the operating time of the device depends on this parameter, since the capacity of the power supply battery is limited.