A tool that estimates the peak magnitude of the transient current drawn by a transformer when it is initially energized. This calculation is crucial for selecting appropriate protective devices like circuit breakers and fuses, and for assessing the potential impact on the power grid. The outcome helps in determining the initial surge of current that can occur, often several times larger than the normal full-load current. As an example, a device projecting a high inrush necessitates using circuit breakers with higher instantaneous trip settings to prevent nuisance tripping during startup.
Accurate estimation is essential for preventing damage to the transformer and ensuring system reliability. Under-estimation can lead to premature failure of protective devices or even transformer damage, while over-estimation can result in unnecessary equipment costs. Historically, simplified methods were used, but modern tools incorporate complex transformer characteristics and system impedance for improved accuracy, leading to more effective protection strategies and minimizing operational disruptions.
