Oklahoma Electrical Practice Exam

For a facility with a 600V service, what is the maximum allowable size for ungrounded conductors?

1. #4 AWG

2. #1 AWG

3. #2/0 AWG

4. #3 AWG

The correct answer is: #2/0 AWG

The maximum allowable size for ungrounded conductors in a 600V service is based on the requirements outlined in the National Electrical Code (NEC) and other relevant standards governing electrical installations. For a 600V service, the conductors must be capable of safely carrying the required load current without exceeding temperature ratings and other performance criteria. Choosing the size of conductors involves considering several factors, including the type of insulation, the allowable ampacity for the specific wire material (either copper or aluminum), and the installation conditions (such as ambient temperature and installation method). In this case, #2/0 AWG conductors are typically suitable for a 600V service, as they have a higher ampacity compared to the other sizes listed. By selecting #2/0 AWG, you ensure that the conductors can safely handle the expected load while complying with the NEC requirements. This incorporates considerations for voltage drop, heat dissipation, and potential derating factors based on the installation environment. Overall, #2/0 AWG represents a safe and compliant choice for a 600V ungrounded conductor application.