358.10 Uses Permitted.
Code Change Summary: The permitted uses of Electrical Metallic Tubing (EMT) was reworded.
In the 2017 NEC®, Section 358.10 was reformatted to bring the uses permitted of Type EMT more in line with the way the uses permitted are structured for RMC and IMC.
An attempt is made in every NEC® Article to follow a specific format in order to make the code as easy to read as possible. For example: The scope of every Article is provided first with a .1 section (see below).
- 300.1 covers the scope of article 300.
- 310.1 covers the scope of Article 310.
- 312.1 covers the scope of Article 312.
The same principle applies to most of the .10 sections (see below).
- 320.10 provides the uses permitted for Type AC Cable.
- 330.10 provides the uses permitted for Type MC Cable.
- 340.10 provides the uses permitted for Type UF Cable.
In the 2017 NEC®, subsections 358.10(A)(B) &(C) were revised for consistency. Some of the rules for the uses NOT permitted were pulled out of 358.12 and reworded into positive language before being placed into 358.10. As well, new rules were added to recognize stainless steel EMT and the proper protection of aluminum EMT.
Below is a preview of Article 358. See the actual NEC® text at NFPA.ORG for the complete code section. Once there, click on their link to free access to the 2017 NEC® edition of NFPA 70.
2014 Code Language:
358.10 Uses Permitted.
(A) Exposed and Concealed. The use of EMT shall be permitted for both exposed and concealed work.
(B) Corrosion Protection. Ferrous or nonferrous EMT, elbows, couplings, and fittings shall be permitted to be installed in concrete, in direct contact with the earth, or in areas subject to severe corrosive influences where protected by corrosion protection and approved as suitable for the condition.
(C) Wet Locations. All supports, bolts, straps, screws, and so forth shall be of corrosion-resistant materials or protected against corrosion by corrosion-resistant materials.
2017 Code Language:
358.10 Uses Permitted.
(A) Exposed and Concealed. The use of EMT shall be permitted for both exposed and concealed work for the following:
(1) In concrete, in direct contact with the earth or in areas subject to severe corrosive influences where installed in accordance with 358.10(B)
(2) In dry, damp, and wet locations
(3) In any hazardous (classified) location as permitted by other articles in this Code
(B) Corrosive Environments.
N (1) Galvanized Steel and Stainless Steel EMT, Elbows, and Fittings. Galvanized steel and stainless steel EMT, elbows, and fittings shall be permitted to be installed in concrete, in direct contact with the earth, or in areas subject to severe corrosive influences where protected by corrosion protection and approved as suitable for the condition.
N (2) Supplementary Protection of Aluminum EMT. Aluminum EMT shall be provided with approved supplementary corrosion protection where encased in concrete or in direct contact with the earth.
N (C) Cinder Fill. Galvanized steel and stainless steel EMT shall be permitted to be installed in cinder concrete or cinder fill where subject to permanent moisture when protected on all sides by a layer of noncinder concrete at least 50 mm (2 in.) thick or when the tubing is installed at least 450 mm (18 in.) under the fill.
(D) Wet Locations. All supports, bolts, straps, screws, and so forth shall be of corrosion-resistant materials or protected against corrosion by corrosion-resistant materials.