One or two through-faults? Probably fine. Twenty through-faults? The cumulative mechanical fatigue can loosen windings, crack insulation, and eventually lead to an internal catastrophic failure.
Key design features include:
Disclaimer: This post provides educational content. Always perform detailed system studies using software like ETAP or SKM and consult with a licensed professional engineer for specific applications. transformer short circuit current
For a 3-phase transformer: ( I_FL = \frackVA \times 1000\sqrt3 \times V_LL ) One or two through-faults
This is found on the nameplate. Typical values: 2% for small distribution transformers, 10-15% for large power transformers. The cumulative mechanical fatigue can loosen windings, crack
Under normal operation, the load impedance limits the current. During a fault, that impedance drops to almost zero. The only thing limiting the current is the transformer's own internal impedance—primarily its leakage reactance.
Whether you are sizing protective relays, selecting switchgear, or specifying a new transformer, always ask: What is the worst-case fault current, and can everything in the path survive it?