The standard specifies that the test duration shall be 0.5 seconds (in line with typical circuit-breaker clearing times) except for systems with high-speed protection (<0.2s), where special provisions apply.
Focuses on the mechanical strength required to withstand the massive electromagnetic forces that try to deform or crush the windings during the first few cycles of a short circuit. Demonstration : Can be proven via a special short-circuit test in a high-power laboratory or a theoretical evaluation based on validated design rules. iTeh Standards Demonstration Methods