What is the primary reason for grounding the tank of the transformers?

Grounding the tank of transformers is essential primarily for safety. The key purpose of this practice is to prevent electric shock or accidental electrocution and to reduce the risk of equipment failure or fire. When the transformer tank is grounded, it creates a low-resistance path for fault currents that may occur during a short circuit or insulation failure. This helps to ensure that any stray voltage dissipates safely into the ground rather than posing a hazard to personnel or affecting equipment operation.

In addition to safety, proper grounding can help ensure that overcurrent protection devices within the electrical system operate correctly in the event of a fault. This minimizes the risk of injury or damage and contributes to the overall reliability and stability of the electrical system. Grounding is thus a critical safety measure in transformer installations.