Junction Boxes for Sensitive Electronic Equipment

Article 647 covers the installation and wiring of separately derived systems operating at 120V line-to-line and 60V line-to-ground for sensitive electronic equipment.

May 23, 2014

Junction boxes used in sensitive electronic equipment systems shall be clearly marked to indicate _____.

a) the system frequency
b) the system voltage
c) the distribution panel
d) b and c

See answer and applicable Code reference

The correct answer is: d) b and c

Article 647 covers the installation and wiring of separately derived systems operating at 120V line-to-line and 60V line-to-ground for sensitive electronic equipment. As noted in 647..4(B), "All junction boxes shall be clearly marked to indicate the distribution panel and the system voltage."