Code Quiz

Apr 9, 2009 1:02 PM, By Steven Owen

When installing cabling in manholes, which are intended for personnel entry, with all of the cabling installed on one wall (opposite electrical equipment), what is the requirement for work space according to Part V of Art. 110?

There is no requirement. Just use good judgment.
With respect to the cabling work space, there must be a minimum depth of 30 in. as you approach the cables, a 36-in. width, and a 72-in. height from the cables to the roof of the manhole.
Excluding any exception(s), there must be a clear space 30 in. wide and, in general, 72 in. of vertical clear space (height/headroom).
Excluding any exception(s), there must be a clear space 36 in. wide and, in general, 72 in. of vertical clear space (height/headroom).

Answer: C

It is intention of 110.72 to provide a clear work space for personnel to install, inspect, maintain, or remove cabling in manholes. However, this section of the Code is only addressing the clear work space required for cabling installations, not equipment.

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.