20% Fill in a Trough Right?

Joethemechanic

Senior Member
Location
Hazleton Pa
Occupation
Electro-Mechanical Technician. Industrial machinery
Screenshot 2025-09-11 133159.pngScreenshot 2025-09-11 133007.png

I took the 3/4 plywood cover someone put on years ago off to use for a pattern to make a new steel cover and discovered another project. What if I fabricate a steel cover with additional space? Or just bite the bullet and replace it with a larger trough?
 
I don't see an issue other than the wood and of course it's very ugly. It's 20% fill for the conductors alone but 75% when there are splices.

376.56(A) Splices and Taps.
Splices and taps shall be permitted within a wireway, provided they are accessible. The conductors, including splices and taps, shall not fill the wireway to more than 75 percent of its area at that point.
 
FWIW, looks like split bolts with several conductors landing in them. Most if not all split bolts were only listed for two conductors.

Looks like it has survived the test of time so far and I can also say I seen very similar installs that lasted for 50 plus years as well.
 
Looks like it has survived the test of time so far and I can also say I seen very similar installs that lasted for 50 plus years as well.
The original install was 1953 lol. Not sure when additional circuits were added. Roughly 5000 sq feet original building and an additional 5000 added in around 1970
 
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