What is the best size to choose for civilian transformers?

When choosing a civilian transformer, the appropriate capacity depends on the specific usage scenario and requirements. ‌

For household appliance transformers, the general recommendation is to choose a transformer that can carry 80% of the rated power of the equipment. This is because inductive loads (such as motors) have a large instantaneous current when starting, so using 70% of the rated power is sufficient. If it is only used for a short period of time, even smaller power can be selected. For example, choosing a 220/110V transformer with a power range of 50-60W can meet the needs of most households, while also providing appropriate power surplus. ‌

For larger civil buildings or residential areas, the selection of transformers needs to consider the reliability of power supply, initial investment costs, and operational economics. When considering transformer capacity, it should be calculated and determined based on actual load. For example, for the calculation of electricity load in residential buildings, the unit index method needs to be combined with coefficients for calculation. For example, a coefficient of 0.6 can be applied to 30 households per unit, a coefficient of 0.5 can be applied to 60 households per building, and a coefficient of 0.4 can be selected for transformers in 240 households. In addition, as mentioned in typical examples, for the case of 900 households, using a three-phase distribution coefficient of 0.26 and a power consumption of 6kW per household, it is appropriate to calculate the transformer capacity with a load of 1404kW. ‌

In summary, when choosing a civilian transformer, the appropriate transformer capacity should be determined based on specific usage scenarios and requirements. For household use, a transformer of 50-60W can be selected; For larger residential areas or civil buildings, it is necessary to calculate the specific electricity load and select the appropriate transformer capacity to ensure the reliability, economy, and environmental friendliness of power supply.