Generally, the general miniature circuit breaker specifications are distinguished by the rated current, mainly 6A, 10A, 16A, 20A, 25A, 32A, 40A, 50A, 63A, 80A, 100A, etc.; general households should pay attention when selecting or checking the total value of the total load current The following points:
1) The value of each branch current
① The power is directly divided by the voltage as indicated on the nameplate of the pure resistive load.
Formula I=power/200v;
For example, a 200w bulb, branch current I=200W/220=0.9A
Resistive load appliances include light bulbs, electric heaters, electric fans, electric frying pans, electric heaters, electric irons, electric blankets, electric rice cookers, vacuum cleaners, electric water heaters, air conditioners, etc.
② The calculation of inductive load is a little more complicated. The power consumption should be considered. The specific calculation should also consider the power factor. In order to facilitate the estimation, a simple calculation method is given. For general inductive loads, specify the power calculated based on the load. Double that is enough. For example, the branch current I of a 200W fluorescent lamp is indicated as I=200W/220v=0.9A, which is doubled to 0.9*2=1.8A (1.5A more than the exact calculated value, 0.3A more).
Perceptual appliances include televisions, washing machines, fluorescent lamps, refrigerators, and fluorescent lamps.
2) The total load current is the sum of the current of each branch
Knowing the branch current and the total current, you can select the specifications of the branch circuit breaker and the main circuit breaker, or check whether the specifications of the designed electrical components meet the safety requirements; in order to ensure safety and reliability, the rated operating current of the electrical components should generally be More than 2 times the required maximum load current; in addition, when selecting electrical components, the possibility of future increase in electrical load should also be taken into account to leave a margin for future demand.