Electrician's Licensing Practice Exam

Disable ads (and more) with a membership for a one time $2.99 payment

Prepare for the Electrician's Licensing Test with comprehensive multiple choice questions and hints. Improve your knowledge, skills, and confidence to excel in your exam!

Practice this question and more.

What size grounded conductor should be used in the service cable for a 200-amp service?

1/0 or 3/0
2/0 or 4/0
4/0 or 6/0
3/0 or 2/0

The correct answer is: 2/0 or 4/0

For a 200-amp service, the appropriate size for the grounded conductor is critical to ensure safety and compliance with the National Electrical Code (NEC). According to NEC guidelines, a grounded conductor must be adequately sized based on the ampacity and the application in which it will be used. In residential and commercial services, typically, the grounded conductor must be sized appropriately to support the overcurrent protection device and the entire load presented on the service. For a 200-amp service, the recommended size for the grounded conductor is indeed either 2/0 or 4/0, depending on the installation conditions and types of conductors used. Using 2/0 provides a suitable grounding path while maintaining safety standards, while 4/0 is sometimes characterized as the upper limit for reduce resistance in large installations or special applications. This sizing ensures that in the event of a fault or short circuit, the grounded conductor will sufficiently carry the fault current to trip the breaker, effectively protecting the service wiring and equipment. Other choices presented may suggest improper sizing for a 200-amp service based on the NEC, which can lead to overheating or equipment failure, underscoring the importance of adhering to the proper size as established in the relevant code.