Oklahoma Electrical Practice Exam

What must be included when metal conduits enter service equipment enclosures with concentric or eccentric knock outs containing service wires?

1. Grounding screws and terminals

2. Bonding bushings and jumpers

3. Weatherproof seals and grommets

4. Labeling and identification tags

The correct answer is: Bonding bushings and jumpers

When metal conduits enter service equipment enclosures with concentric or eccentric knock outs containing service wires, it is essential to ensure effective grounding and bonding of the system. The inclusion of bonding bushings and jumpers is crucial because these components enhance the electrical continuity and grounding of the conduit system. Bonding bushings connect the conduit to the enclosure, ensuring that any potential fault currents can safely flow to ground, mitigating the risk of electrical shock or fire. The use of jumpers further addresses any potential difference in electrical potential between the conduit and the service equipment enclosure, maintaining a safe and effective grounding system. In this context, grounding screws and terminals, weatherproof seals and grommets, and labeling and identification tags do not directly relate to the requirements for electrical bonding and grounding in metal conduits entering service equipment. While they may play roles in overall electrical safety and compliance, the specific need in this scenario focuses on preventing electrical hazards through effective bonding practices, which is why bonding bushings and jumpers are the correct components to include.