Input current

The input current is the electrical current that flows into an electrical device, circuit or system. It is generated by the applied input voltage and depends on the electrical load and the characteristics of the consumer.

For transformers, the input current refers to the current on the primary side. Its level is directly related to the power consumed and the transformation ratio of the transformer. The higher the transmitted power, the higher the input current.

The input current can occur as direct current (DC) or alternating current (AC). In three-phase systems, it is divided into three phase-shifted currents.

Correct sizing of the input current is important for the safe operation of electrical systems. Currents that are too high can overload cables, components or fuses, while currents that are too low can indicate an inadequate supply or malfunction.