Switchgear Protections - Study Mode

Explanation

Solution: A short circuit in any winding of a transformer is primarily caused by insulation failure . The insulation in a transformer is responsible for preventing electrical contact between different windings and between windings and the core. Factors such as aging, overheating, moisture, and electrical stress can degrade the insulation, leading to its breakdown. Once the insulation fails, the winding conductors come into direct contact, resulting in a short circuit . Other factors like mechanical vibration, loose connections, and impulse voltage may contribute to insulation deterioration but are not the direct cause of a short circuit. Hence, the correct answer is Insulation Failure (Option B).