Bonding hardware on wood structures above 230 kV primarily serves to address which hazard?

• A. Increases the paths to ground for transient over voltages
• B. Eliminates corona and radio noise from the line
• C. Completes the grounding circuit
• D. Eliminates air gaps where arcing might develop and cause fires

Answer: (D)

Bonding on wooden structures around high-voltage lines is about preventing arcing across air gaps by keeping all metal parts at the same electrical potential. When the line experiences a surge—like a lightning strike or switching transient—small air gaps between hardware can momentarily have large voltage differences. Those gaps can arc, sparking and potentially igniting dry wood or other combustible materials on the pole. By bonding the hardware, you create a continuous conductive path that equalizes voltage across components, so the risk of arcing through those gaps drops dramatically. This is the primary safety goal for bonding at these voltages.

Other options aren’t the main effect here: bonding isn’t primarily about increasing a ground path to earth, nor about removing corona or radio noise, and it doesn’t serve to “complete” the grounding circuit in the sense of Earth grounding. The key idea is reducing the air-gap arcing that could start fires on or near the structure.