Where is the hazard of high fault current especially critical?

High fault current poses a significant hazard near the source of the electrical system because this is where the maximum current is generated when a fault occurs. Electrical equipment, such as generators and transformers, are designed to handle a certain level of fault current. When a fault occurs, the protective devices need to operate efficiently to isolate the fault and minimize damage to the system. If the fault is near the source, the current can be much higher, leading to increased risks such as equipment damage, arcing, and potential hazards to personal safety.

In contrast, as you move further from the source, the fault current typically decreases due to impedance in the electrical system. This means the systemic risk is not as pronounced further down the line, such as at the load or in distribution lines. Although equipment at the transformer or in distribution lines can also face challenges from high fault currents, the source is where the initial fault current can cause the most immediate and critical issues, making it vital to have robust protection systems in place.