What does the term 'earthing' refer to in electrical installations?

The term 'earthing' in electrical installations refers to grounding electrical systems for safety. This practice involves establishing a direct physical connection between electrical systems and the Earth, which serves as a reference point for voltage and ensures that any fault current has a safe pathway to follow. By grounding systems, earthing protects both equipment and individuals from potential electric shock and fire hazards that can arise from fault currents.

Grounding serves several critical purposes: it helps to stabilize voltage levels during normal operation, reduces the risk of electrical shock, provides a path for lightning strikes to dissipate safely, and ensures that protective devices like circuit breakers operate correctly in the event of a fault. This safety measure is crucial in preventing hazardous situations that could lead to injury or damage.

The other options do not accurately describe the concept of earthing. For instance, connecting circuits to each other for efficiency may relate to improved electrical performance but does not touch on the safety aspect that earthing provides. Isolating electrical systems from the ground contradicts the very essence of earthing, which involves creating a connection. Using metal conduits for wiring is a method of installation that may enhance protection from physical damage or electromagnetic interference, but it does not address the grounding of electrical systems.