What is a fundamental requirement for an electrical system design regarding equipment used during faults?

A fundamental requirement for electrical system design is that it must meet or exceed the short-circuit current rating available during a fault. This is crucial because during a fault condition, such as a short circuit, the electrical system experiences current levels that can exceed normal operational currents significantly. If the equipment does not have a sufficient short-circuit current rating, it may not withstand these high currents, leading to potential equipment failure, fire hazards, or even a dangerous situation for personnel.

The design must ensure that all components, including circuit breakers, fuses, and other protective devices, can handle these extreme conditions without failing. By meeting or exceeding the expected short-circuit currents, the system can ensure reliability and safety, providing adequate protection not only for the equipment but also for those who operate the system. This aspect is fundamental to compliance with safety codes and standards, ultimately protecting both the infrastructure and human life.