Send to a Friend View / Add Comments  

Some of you have completed our Online Continuing Education Courses which include video instruction. For the rest of you we are sending a weekly series of newsletters featuring an instructional page complete with videos.

To view the videos you will need to download the free Real Player Download Real Player plugin for your browser - if you don't already have it. After installing Real Player, you can view the videos by clicking on one of these icons:

  • Click on this icon Hi Res - Cable/DSL if you have a cable or DSL connection.
  • Click on this iconLow Res - Modem if you have a Dial-up connection.

Below is the full course page which includes these videos:


Article 547 Low Res - Modem Hi Res - Cable/DSL        Page 4 of 7
Agricultural Buildings

547.5 Wiring Methods

This section was revised to require equipment enclosures, boxes, conduit bodies, and fittings installed in agricultural buildings to comply with the following requirements:

(C) Equipment Enclosures, Boxes, Conduit Bodies, and Fittings.
(1) Excessive Dust.
AEquipment enclosures, boxes, conduit bodies, and fittings installed in areas of agricultural buildings where excessive dust may be present must be designed to minimize the entrance of dust and have no openings (such as holes for attachment screws) through which dust could enter the enclosure.

Author’s Comment: Dust ignitionproof enclosures are not required and weatherproof boxes could be used to meet this requirement. Figure 547-2

(2) Damp or Wet Locations. In damp or wet locations of agricultural buildings, equipment enclosures, boxes, conduit bodies, and fittings must be located or equipped to prevent moisture from entering or accumulating within the enclosure, box, conduit body, or fitting. In wet locations of agricultural buildings, including normally dry or damp locations where surfaces are periodically washed or sprayed with water, boxes, conduit bodies, and fittings and must be listed for use in wet locations, and equipment enclosures must be weatherproof.

(3) Corrosive Atmosphere. Where wet dust, excessive moisture, corrosive gases or vapors, or other corrosive conditions may be present in an agricultural building, equipment enclosures, boxes, conduit bodies, and fittings must have corrosion resistant properties suitable for the conditions.

Intent: The new text clarifies that the types of enclosures required in agricultural buildings are dependent upon the conditions where the enclosures are installed.


Figure 547-2
Click on Image to Enlarge

Copyright © 2004 Mike Holt Enterprises,Inc.
1-888-NEC-CODE (1-888-632-2633)