Inrush current

When power equipment is started, a current larger than normal flows due to the charging current of the capacitor inside the equipment. Then, due to transient phenomena, as the capacitor becomes charged, the current value decreases, and once it is fully charged, it settles to a normal value. The maximum value of the input current from the startup of the power equipment until it reaches a steady state is called the inrush current. Since inrush current adversely affects power equipment, it is often equipped with a safety function that limits the input current at startup.