3-phase isolation transformer capacity calculation method

Calculate the high power per phase of the load

Add the A-phase, B-phase and C-phase load power independently, such as A-phase load total power 10KW, B-phase load total power 9KW, C-phase load total power 11KW, take the larger value 11KW. (Note: single-phase load The power of each device is calculated according to the value on the nameplate. The power of the 3-phase device divided by 3 is equal to the power of each phase of this device.)

For example: C-phase load total power=(computer 300W X 10 units) plus (air conditioner 2KW X 4 units)=11KW

Calculate the total power of the 3-phase isolation transformer

11KW X 3-phase=33KW (transformer 3-phase total power)

3-phase total power\/0.8, this is a very important step. Currently, the power factor of transformers sold on the market above 90% is only 0.8, so it needs to be divided by the power factor of 0.8.

33KW\/0.8=41.25KW (transformer total power)

The total power of the transformer\/0.85 is greater than that according to the power engineering design manual, and the transformer capacity should be selected according to the calculated load. For a single transformer that supplies power with a stable load, the load rate is generally about 85%.

41.25KW\/0.85=48.529KW (transformer power to be purchased), then you can choose a 50KVA transformer when purchasing.