How To Size A Transformer kVA

Calculate the load of the transformer. For a power distribution system with stable power supply, the load rate of the transformer can reach about 85%, that is to say, the power of the transformer can reach 85% of the rated capacity of the transformer. Conversely, to know how much the total load of electricity is, you only need to divide it by 0.85, which is the capacity of the transformer that needs to be installed.

However, considering the fluctuation of electricity consumption during the operation of the transformer, there are peak and valley periods of electricity consumption, so the load rate of the transformer is generally 60%~70%, which is more appropriate. Because the capacity of the transformer is made according to a certain level, it should be large rather than small when selecting the capacity of the transformer.

Matters needing attention in transformer capacity selection:

1. You must first understand the voltage required by the equipment, the actual power of the user and the conditions of the site. Generally, the capacity, voltage, current and environmental conditions of the transformer should be considered. The capacity of the transformer should be selected according to the power, nature and use of the user's electrical equipment. time to determine the load required.

2. When the transformer is running, the power load it bears should be about 75%~90% of the rated capacity of the transformer. If the actual load is less than 50% during operation, a small-capacity transformer should be replaced.

3. While selecting the capacity of the transformer, determine the input voltage value of the transformer according to the line, and select the output voltage value according to the electrical equipment. It is best to choose a three-phase four-wire power supply, which can provide industrial power and lighting power at the same time.

4. For the selection of current, attention should be paid to meet the power demand of the equipment when the load starts.

The determination of transformer capacity should accurately count all power loads, consider the characteristics of power consumption, and select the appropriate transformer capacity. If the capacity of the transformer is too large, it will increase the basic electricity bill and increase the loss. If the capacity is too small, it will easily trip and generate heat.