OESC 300.5(G) Raceway Seals.

In a basement, an underground raceway entering the top of a panelboard cabinet from outside may have the potential to allow condensation or moisture into the cabinet.
Click to Enlarge
In a basement, an underground raceway entering the top of a panelboard cabinet from outside may have the potential to allow condensation or moisture into the cabinet.

NEC Section 300.5(G) requires conduits or raceways through which moisture may contact live parts to be sealed or plugged at either or both ends. This also includes spare or unused raceways. Any sealants used for this purpose must be identified for use with the cable insulation, conductor insulation, bare conductor, shield, or other components.

Oregon has amended this section and deleted the following statement from the code section:

“Sealants shall be identified for use with the cable insulation, conductor insulation, bare conductor, shield, or other components.”

Oregon amendments to the 2023 NEC® are located in “Table 1-E” of the Oregon Electrical Specialty Code (OESC) which can be seen using the following link or the OESC PDF file located near the bottom of the screen: 2023 OESC

  Click here to view the OESC  

Did You Like This? Let Us Know With A Like! Thanks!

OESC 300.5(G) Raceway Seals.

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

In Oregon, which of the following is true for an underground raceway entering a basement and terminating into the top of a panelboard as in the image?

A: Sealants used to plug the end shall be identified for use with the cable insulation.
B: The raceway must be sealed at either or both ends.
C: Sealants used to plug the end shall be listed.
D: No seal is required if the raceway is a spare.
Please register or sign in for electrical continuing education courses.

If you were already signed in, your session probably expired, please sign back in.