Installation of electrical power production sources operating in parallel with a primary source(s) of electricity shall be performed ___ by qualified persons.

• A. Only
• B. and overseen
• C. Or overseen
• D. Or reviewed

Answer: (A)

The requirement here is about who is allowed to perform the installation of power sources that operate in parallel with the primary utility. When you have sources interconnected with the main electrical system, the work involves complex interconnection, synchronization, protection, and safety considerations. To ensure safety and code compliance, this type of installation must be done only by someone who has the appropriate training, skills, and knowledge—defined as a qualified person. That’s why the correct completion is “Only.” It rules out the idea that supervision or review by others would substitute for the actual installation being performed by someone qualified.