Oklahoma Electrical Practice Exam

The correct answer is based on the requirements outlined in electrical codes concerning the protection of underground installations. For enclosures housing wires that operate above 600 volts, safety standards are heightened due to the higher risk associated with voltage levels in this range. The specified minimum weight requirement for a metal underground box cover being 100 pounds ensures that the cover can resist accidental impact and prevent unauthorized access, while also minimizing the chances of damage to the electrical components within the enclosure.

Metal covers are preferred in these applications because they provide a robust barrier against physical threats, such as falling debris or ground movement, which could otherwise compromise the integrity of the wiring. The weight requirement thus acts as a critical aspect of safety and reliability in electrical installations, ensuring that covers can withstand significant stress and protect the electrical infrastructure effectively.

This requirement is set forth to ensure that installations comply with safety codes designed to protect both the infrastructure and public safety, which is crucial when dealing with high-voltage systems.