At what intervals should a steel beam down conductor be connected to the grounding system?

The correct answer indicates that a steel beam down conductor should be connected to the grounding system at intervals of 60 feet or less. This standard is in place to ensure that the grounding system provides adequate protection against electrical faults and lightning strikes.

The rationale behind this interval is that a closer connection point minimizes the potential for voltage differences that could arise due to ground potential rise, especially during a fault condition. By establishing connections at 60 feet or less, the effectiveness of the grounding system is enhanced, as it maintains a low impedance path to ground, which is crucial for the safety and reliability of electrical systems.

This practice helps in reducing the risk of electrical surges and ensures that any stray voltage is effectively dispersed, protecting both personnel and equipment from electrical hazards. Achieving this connection at appropriate intervals is foundational in maintaining the integrity and effectiveness of an electrical grounding system within facilities that handle explosives and other sensitive materials.