What is required for fittings used in electrical metallic tubing and rigid metal conduit?

Fittings used in electrical metallic tubing and rigid metal conduit must be listed, meaning they have been tested and certified for safety and performance by a recognized standards organization. This ensures that the fittings meet specific criteria for strength, durability, and reliability when used in electrical installations.

Being listed indicates that these fittings have undergone rigorous examination and comply with the relevant codes and standards, ensuring they are suitable for their intended use. This certification is essential in maintaining safety and minimizing the risk of electrical failures or hazards in the system.

While having approved components is important, the term "approved" can sometimes be less specific and may not imply the same level of testing and adherence to standards as "listed." Fittings that are custom-made may not have undergone standard testing, and standardized fittings must still be verified for compliance, but the primary requirement focuses on listing for safety and performance assurance.