Which voltage systems are classified as solidly grounded?

Solidly grounded systems are those where one of the conductors, usually the neutral, is directly connected to the ground without any impedance. In these systems, the ground connection is intended to provide a low-resistance path for fault currents, which helps ensure the safety and reliability of the electrical system.

The classification of solidly grounded systems encompasses a range of common voltage configurations, including both three-phase and single-phase power systems. The 120/240-volt system, often used for residential applications, can be solidly grounded, primarily when designed that way to provide safety and stable operation. Similarly, the 120/208-volt and 277/480-volt three-phase systems, widely used in commercial and industrial settings, are also capable of being solidly grounded to enhance fault protection and minimize electrical hazards.

Therefore, the idea that all listed voltage systems can be classified as solidly grounded is accurate, as each of these systems can be configured to have a solid ground connection depending on the specific installation and safety requirements. This characteristic is crucial in ensuring effective fault current management and in maintaining the overall safety of the electrical installations.