If a panelboard is rated less than 1000 volts, what is required?

Overcurrent protection is essential for any panelboard rated less than 1000 volts to ensure safety and system integrity. This protection is designed to prevent excessive current from damaging electrical devices, wiring, and equipment. Without it, there is a significantly higher risk of fires, equipment failure, and electric shock hazards.

The requirement for overcurrent protection aligns with electrical codes and standards that emphasize maintaining safety in electrical installations. Such protection is typically provided through circuit breakers or fuses, which automatically interrupt the electrical supply in the event of an overload or short circuit. This proactive measure helps to safeguard both people and property, making it a critical aspect of electrical system design and maintenance.

In contrast, the other options either misinterpret the requirements or present incorrect practices regarding panelboard installations. For instance, while grounding is important for safety, the claim that no grounding is necessary contradicts standard practices, and stating that all circuits must be grounded is an overgeneralization not explicitly tied to panelboard ratings. Additionally, suggesting that grounding can be done after installation ignores the necessity for ensuring safety from the outset. Therefore, the necessity of overcurrent protection is the correct and appropriate requirement for panelboards with a rating under 1000 volts.