Illustrated Catastrophes

Jan 1, 2004 12:00 PM, By Joe Tedesco, NEC Columnist

More Code Catastrophes

As usual, never consider the following commentary associated with these photos as a formal interpretation of the National Electrical Code (NEC). Without criticizing anyone or any product, the following scenarios present us with serious safety questions.

RUSTY CATCH BASIN

This wireway was secured to a block wall in the basement of a commercial building. Unless identified for use in the operating environment, neither conductors nor equipment may be located in damp or wet locations; where exposed to gases, fumes, vapors, liquids, or other agents that have a deteriorating effect on the conductors or equipment; or where exposed to excessive temperatures. Equipment identified only as “dry locations,” “Type 1,” or “indoor use only” must be protected against permanent damage from the weather during building construction (110.11, Deteriorating Agents).

CORROSIVE EFFECTS OF THE EARTH

Per 358.10(B), you may install ferrous or nonferrous EMT, elbows, couplings, and fittings in concrete, in direct contact with the earth, or in areas subject to severe corrosive influences, as long as they have corrosion protection and are deemed suitable for the conditions. By the looks of this installation, the original installer either ignored this requirement or was unaware of it.

For more specific guidance on this topic, refer to the UL Directory, which states, “Galvanized steel electrical metallic tubing installed in concrete on grade or above generally requires no supplementary corrosion protection. Galvanized steel electrical metallic tubing in concrete slab below grade level may require supplementary corrosion protection. In general, galvanized steel electrical metallic tubing in contact with soil requires supplementary corrosion protection. Where galvanized steel electrical metallic tubing without supplementary corrosion protection extends directly from concrete encasement to soil burial, severe corrosive effects are likely to occur on the metal in contact with the soil. Aluminum electrical metallic tubing used in concrete or in contact with soil requires supplementary corrosion protection. Supplementary nonmetallic coatings presently used have not been investigated for resistance to corrosion.”

ONLY HALF THE SPACE

Per 110.26(A)(1)(a), you're not required to provide working space in the back or on the sides of assemblies, such as dead-front switchboards or motor control centers, where all connections and all renewable or adjustable parts, such as fuses or switches, are accessible from locations other than the back or sides. Where rear access is required to work on nonelectrical parts on the back of enclosed equipment, a minimum horizontal working space of 30 inches is required. The minimum clear distances for working spaces about electrical equipment is listed in Table 110.26(A)(1). This installation clearly violates those requirements.

DON'T BLAME THE ELECTRICIAN

These two disconnects were installed by the electrician in the space identified on the project plans. Then the HVAC contractor installed the refrigeration equipment. The addition of the equipment created a violation of clear working space around the electrical equipment. The working space in the direction of live parts can't be less than what's specified in Table 110.26(A)(1) unless the requirements of 110.26(A)(1)(a), (b), or (c) are met. Distances must be measured from the exposed live parts or from the enclosure or opening if the live parts are enclosed.

Found a Code violation? Send your photos to Joe Tedesco at 350 North St., Boston, MA 02113 or CodeViolations@JoeTedesco.com.