The purpose of special separately derived systems for sensitive electronic equipment is to reduce objectionable noise in sensitive electronic equipment in _____ locations.
c) a or b
See answer and applicable Code reference
The correct answer is: c) a or b
The provisions of Art. 647 cover the installation and wiring of separately derived systems operating at 120V line-to-line and 60V to ground for sensitive electronic equipment. As noted in condition (1) of Sec. 647.3, "The system is installed only in commercial or industrial occupancies."