Parts of an electrical system that should be connected to earth ground include:

Connecting various parts of an electrical system to earth ground is crucial for safety and functionality. Non-current carrying metal parts should indeed be connected to earth ground to prevent potential electrical shock hazards. These metal parts can include the casings of electrical equipment, enclosures, and other non-live components that might accidentally become energized due to a fault in the system. Grounding these parts provides a low-resistance path for fault currents to flow safely to the ground, thereby reducing the risk of electrical hazards.

When non-current carrying metal parts are grounded, any fault condition can cause a circuit breaker to trip, thereby disconnecting the power supply and ensuring that the equipment remains safe to operate. This protective measure is fundamental in electrical safety protocols and is widely endorsed in electrical codes and standards.

In contrast, other options either limit grounding to only specific components that may not provide sufficient protection or misidentify parts that shouldn’t be grounded. Therefore, grounding all non-current carrying metal parts is a comprehensive safety measure that addresses potential electrical risks effectively.