The transformer tank is grounded and __________ to the Primary and secondary common neutral ground wire.

• A. Isolated
• B. Connected
• C. Fused
• D. Insulated

Answer: (B)

Grounding and bonding a transformer tank to the system neutral provides a solid reference to earth and a low-impedance path for fault current. When the tank is connected to the primary/secondary common neutral ground wire, any fault that involves the tank can travel back to the source through the grounding network, allowing overcurrent protection to operate quickly and safely. This bond also keeps the tank at or near earth potential, reducing the risk of dangerous touch voltages. Leaving the tank isolated or insulated would remove the necessary fault-current path and safety reference, while simply fusing the connection isn’t about bonding the tank itself. Hence, the correct practice is to connect the tank to the neutral grounding conductor.