How to calculate the rated capacity of small transformers for lighting purposes?
If the flow of large capacity motor starting current and welding machine, large current flows in a short period of time in the load even when the power equipment capacity can withstand current flow in a short time, but due to a voltage drop excitation electromagnetic switch relief, the motor can not start, damaged or the undesirable phenomenon of welding. Therefore, the voltage drop rate should be calculated as less than 10% of the supply voltage, as calculated below.
But in fact, consider the total load, the importance, the location of the machine, and the future additional plan, according to the following order.
In view of the power [kVA] conversion of each load, multiplied by the amount of consumption, according to the importance of the load, equipment location, voltage statistics, set the load line and load place of plastic case transformer capacity and its connection position. The future load power equipment shall be judged on the basis of prior installation or consideration of the economy in terms of equipment addition, installation, etc..
Capacity of power transformer is the basic equipment for a total capacity of [kW] (maximum power consumption rate by a / X100 capacity) divided by the power load [%] value for benchmarking.
