Which of the following items must be bonded to the Operator Position SBB?

• A. Type 3 SPDs, PDUs, and UPS Chassis
• B. Type 3 SPDs only
• C. PDUs only
• D. UPS Chassis only

Answer: (A)

Bonding at the Operator Position SBB creates a single, low-impedance grounding path for all equipment in that area, which is essential for effective surge protection, safety, and a stable grounding reference.

Type 3 surge protection devices need a solid return path to ground to clamp and divert surge energy. If they aren’t bonded to the SBB, surge currents may seek other paths, reducing protection and potentially damaging equipment or posing safety risk.

Power distribution units and UPS chassis are metal enclosures that can become energized or carry fault currents. Bonding them to the Operator Position SBB ensures they share the same ground reference as other equipment, minimizes potential differences, and helps prevent shock hazards and electrical noise.

Having all three bonded to the same SBB keeps the grounding scheme coherent and compliant. If only one or two were bonded, the remaining components could float relative to the ground, undermining protection and safety.