Power Distribution Transformer Capacity Unit

The unit of power distribution transformer capacity is KVA, that is, apparent power. Most electrical loads are inductive loads, and their apparent power is equal to the vector sum of active power and reactive power. Therefore, the apparent power of the inductive load is greater than the active power. If the power distribution transformer is selected with active power, the apparent power of the inductive load must be greater than the capacity of the power transformer, and the load current must exceed the allowable value of the transformer. Therefore, the inductive load must use the apparent power to select the transformer.

If the loads on the transformer are all resistive loads, the total power can be equal to the KVA value of the transformer.

What about KVA instead of KW? VA or KVA is the apparent power used in the AC line, also known as the capacity, which is the product of the voltage and the rms value of the current. But it will affect the load design of the power distribution transformer, so it is more accurate to use VA or KVA to calculate. And W or KW is what we usually call it.