What is a heavy or dead ground?

A heavy or dead ground refers to a ground with very low resistance, which is crucial for electrical safety and effective operation of electrical systems. In the context of electrical installations, a heavy ground provides a reliable path for fault currents to dissipate safely into the earth, thereby minimizing the risk of electric shock or equipment damage during fault conditions.

Having low resistance is important because it ensures that any stray or fault current has a minimal impedance path, allowing it to quickly travel to the ground. This is vital for the protection of both personnel and equipment, as it helps to ensure that overcurrent protection devices operate correctly and promptly disconnect circuits in case of faults.

The other options do not accurately describe the concept of a heavy or dead ground. A disconnected ground would not offer any grounding effectiveness, fluctuating resistance levels would impair the reliability of the ground connection, and limiting the use of ground to emergency situations does not fit the definition or intended use of a heavy or dead ground in electrical systems.