zcanyonboltz
Senior Member
- Location
- denver
I'm not sure what step I'm doing wrong. A 4x4x12 wireway is 192 cubic inches. I take 192 x.20 for the 20% fill rule=38.4. cubic inches. Then I take 38.4 and divide by 0.0133 which is the inch squared area of a #12 THHN from Table 5. 38.4/0.0133=2,887.21. There is now way that's how many #12 THHN can go in 12x12x4 wireway. If I take 38.4/2.25 for box fill size for a #12 I get 17.06. I lent my Mike Holt exam book to a coworker and haven't done this for a while.
Where am I messing up? Thanks
Where am I messing up? Thanks