The standard identifies two distinct modes of failure that the unit must resist: forces and thermal energy. 2. Thermal Ability to Withstand Short Circuit
: Verification includes measuring the change in short-circuit reactance (which indicates winding movement) and performing a visual "in-tank" inspection after the test. iec 60076-5
: The transformer is subjected to a series of short-circuit "shots" at full system voltage. The standard identifies two distinct modes of failure
When a short circuit occurs, the current in the windings can increase to many times the rated value. This causes rapid Joule heating. : The transformer is subjected to a series
: Typically, transformers must be designed to withstand these thermal effects for a duration of 2 seconds .
This is a conducted at high-power laboratories like KEMA Labs.
Compliance with this standard is critical for utilities and manufacturers to ensure that high-value power assets do not fail catastrophically during grid faults. 1. Scope and Core Objectives