Which components must be bonded to the building ground?

Bonding components to the building ground is essential for ensuring safety and reducing the risk of electric shock, equipment damage, and fire hazards. In the context of this question, bonding typically involves connecting metal components to the grounding system to maintain a shared electrical reference and to facilitate the safe operation of equipment.

The selection of metal conduits and metal cabinets as components that must be bonded to the building ground is correct because both materials can conduct electricity. If a fault were to occur, such as a short circuit, bonding these metal components to the ground allows excess current to safely dissipate into the ground, preventing dangerous voltage levels that could expose users to electric shock.

Additionally, metal conduits often protect electrical wiring and are necessary for safety codes to prevent electrical hazards. Metal cabinets, serving a similar protective role, need to be grounded to ensure that any electrical faults are handled safely.

In contrast, options that involve plastic conduits or cabinets are not correct since plastics are non-conductive materials and do not require grounding. Grounding plastic components does not serve a purpose in the same safety context. Similarly, wood cabinets do not conduct electricity and therefore do not need to be bonded to the building ground.