300.7(B) Expansion, Expansion-Deflection, and Deflection Fittings.

PVC raceways are not the only type that could benefit from an expansion fitting. This rigid metal conduit expansion fitting was needed on the roof to compensate for thermal expansion. Go to Thomas & Betts for a look at an example of expansion/deflection fittings.
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PVC raceways are not the only type that could benefit from an expansion fitting. This rigid metal conduit expansion fitting was needed on the roof to compensate for thermal expansion. Go to Thomas & Betts for a look at an example of expansion/deflection fittings.

Code Change Summary: New rules were added to account for deflection of raceways.

In the 2014 NEC®, Section 300.7(B) provided rules pertaining to expansion fittings for raceways exposed to different temperatures. In the 2017 NEC®, these rules have been expanded (no pun intended) and now apply to the use of expansion fittings, expansion/deflection fittings, or just deflection fittings.

Many electrician associate expansion fittings with PVC raceways only. Movement can occur for any type of raceway. Many people have no idea that expansion fittings may be needed on more than just PVC raceways. As well, section 300.4(H) has additional requirements for using expansion/deflection fittings for a raceway crossing a structural joint in buildings, bridges, parking garages, or other structures.

Be sure to look at the label on the fitting. Some are listed for expansion and contraction only while others may be suitable for expansion and deflection or deflection only.

Below is a preview of Article 300. 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:

300.7(B) Expansion Fittings. Raceways shall be provided with expansion fittings where necessary to compensate for thermal expansion and contraction.

2017 Code Language:

300.7(B) Expansion, Expansion-Deflection, and Deflection Fittings. Raceways shall be provided with expansion, expansion-deflection, or deflection fittings where necessary to compensate for thermal expansion, deflection, and contraction.

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300.7(B) Expansion, Expansion-Deflection, and Deflection Fittings.

Below is a Real Question from our Electrical Continuing Education Courses for Electrical License Renewal:

Which of the following is true when installing rooftop raceways exposed to different temperatures?

A: All rooftop raceways require deflection fittings.
B: Raceways shall be provided with expansion, expansion-deflection, or deflection fittings where necessary to compensate for thermal expansion, deflection, and contraction.
C: Only PVC raceways require expansion fittings.
D: All rooftop raceways require contraction fittings.
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