Oklahoma Electrical Practice Exam

In a residential setting, what is the minimum size grounding electrode conductor required for a 200a service?

1. #6 AWG

2. #8 AWG

3. #4 AWG

4. #10 AWG

The correct answer is: #4 AWG

The minimum size grounding electrode conductor for a 200-amp service is dictated by the National Electrical Code (NEC) standards. Specifically, for a residential setting with a 200-amp service, the code requires the use of a grounding electrode conductor that is appropriately sized to ensure safety and reliability. A #4 AWG copper conductor is necessary for a 200-amp service because it provides adequate capacity to handle potential fault currents and helps maintain a low impedance path to ground. This is crucial for the effective operation of overcurrent protective devices, such as circuit breakers. By ensuring that the grounding electrode conductor is of the proper size, you enhance the safety of the electrical system, helping to prevent electrical shock and equipment damage. Using a smaller conductor, such as #6 AWG or #8 AWG, would not meet the minimum requirement, potentially compromising the safety and functionality of the grounding system. Thus, the selection of #4 AWG aligns with the NEC's requirements for a secure grounding system in residential electrical installations.