Oklahoma Electrical Practice Exam

How many circuit breakers can be used to individually protect the supply side of each panel board?

1. 1

2. 2

3. 3

4. 4

The correct answer is: 2

The correct answer indicates that two circuit breakers can be used to individually protect the supply side of each panel board. In electrical systems, the National Electrical Code (NEC) allows for individual circuit protection for panel boards to enhance safety and reliability. This is important because it enables the isolation of circuits in case of overload or fault conditions, preventing further damage to both the panel board and connected loads. Using two circuit breakers can provide better redundancy. If one breaker trips due to an overload or fault, the other can still maintain power to other circuits, allowing for continued operation of non-affected areas. This approach also enables more efficient maintenance or troubleshooting, as one breaker can be turned off while the other remains operational. Moreover, this setup is generally applicable in systems where there is a need to manage multiple electrical loads effectively or give multiple levels of protection to different zones of the panel. Hence, specifying two circuit breakers aligns with common practices in electrical design and code requirements.