Code Quiz

Jul 23, 2004 1:13 PM, By Steven Owen

Consider a large industrial complex with multiple buildings. According to the 2002 NEC, what would the proper location for the plaque or directory be for the eight 3,000A feeders that are installed between the eight 2,500kVA substation, 480V secondaries located outdoors and the eight 3,000A, 480V switchgear(s) located in the electrical room(s) inside one of the industrial buildings. This complex is under single management.

A) A sign shall be placed at each feeder location denoting all other services, feeders, or branch circuits that supply that building or structure or pass through that building or structure and the area served by each.
B) A red sign shall be placed at each feeder location to denote all other services, feeders, or branch circuits that supply or pass through that building or structure and the area served by each.
C) A plaque or directory shall not be required for large-capacity, multibuilding industrial installations under single management, where it’s ensured that disconnection can be accomplished by establishing and maintaining safe switching procedures.
D) Each disconnecting means shall be marked as a service disconnect.

Answer: C

Explanation: According to Sec. 225.37, where a building or structure has any combination of feeders, branch circuits, or services passing through or supplying it, a permanent plaque or directory shall be installed at each feeder and branch-circuit disconnect location denoting all other services, feeders, or branch circuits supplying that building or structure or passing through that building or structure and the area served by each.

Exception No. 1: A plaque or directory shall not be require for large-capacity multibuilding industrial installations under single management, where it is ensured that disconnection can be accomplished by establishing and maintaining safe switching procedures.

Owen is the owner and president of National Code Seminars and the holder of master electrician certifications in 46 states.