Fill in the blanks with the correct answers. New requirements for marking of cable trays apply when the cable trays installed within substations contain conductors _________. The warning notice shall be installed in a conspicuous position along the cable tray at intervals not to exceed ____ ft.

  1. with 600V insulation; 20
  2. cable tray rated; 50
  3. rated higher than 600V; 10
  4. rated higher than 35kV; 20

Answer: C

A new section has been added to Art. 225 of the 2011 NEC. Section 225.70 outlines the warning sign requirements in substations. The term "substation" is also a new definition in Art. 100.

As noted in 225.70(A)(1)(c), a "DANGER — HIGH VOLTAGE" sign shall be placed "on all cable trays containing high-voltage conductors with the maximum spacing of warning notices not to exceed 10 ft." ANSI Z-535.2 or ANSI Z-535.4 may also provide guidelines for the warning notice.

Owen is the owner and president of National Code Seminars and the holder of master electrician certifications in 46 states. He can be reached at necexpert@aol.com.