342.20 IMC sizes
What changed in 342.20
The largest IMC allowed went from trade size 4 to trade size 6, matching rigid metal conduit.
Point by point
- The maximum IMC size went from trade size 4 up to trade size 6.
The full lesson is in the Pro Version
Get the whole breakdown
- 2 more points on exactly what changed
- The 2020 rule next to the 2023 rule, side by side
- Why it changed
- What to do and check on the job
One membership unlocks every NEC® change lesson for 2020, 2023 and 2026, plus every video, quiz, flashcard and the Testing Center.
Checking your membership…
This section across NEC® editions
2020 NEC®No change
This section did not change from 2017 to 2020.
2023 NEC®RevisedYou're here
The largest IMC allowed went from trade size 4 to trade size 6, matching rigid metal conduit.
2026 NEC®No change
This section did not change from 2023 to 2026.
More 2023 changes in Article 342
This is a plain-English summary, not the NEC®'s exact wording. Always check the full section in the NEC® edition your area has adopted, plus any local amendments.
NEC® and National Electrical Code® are registered trademarks of the National Fire Protection Association (NFPA). Electrical Exam Coach is not affiliated with or endorsed by NFPA.
Find it faster on test day