(B) Metallic Wireways Used as Pull Boxes.
Where insulated conductors 4 AWG or larger
are pulled through a extend 4.5m (15 ft) or more in both directions from the wireway, the distance between raceway and cable entries enclosing the same conductor shall not be less than that required by 314.28(A) (1) for straight pulls and 314.28(A) (2) for angle pulls. When transposing cable size into raceway size, the minimum metric designator (trade size) raceway required for the number and size of conductors in the cable shall be used.
Statement of Problem and Substantiation for Public Input
It is common practice to install wireways at equipment where the distances between conductor entry/exit points do not comply with the rules found in 314.28(A) (1) or (2). The current code rule does not permit this application. Most inspection authorities permit the installation of wireways containing conductors sized #4 and larger without requiring compliance with the rules in 314.28, where the wireway has been installed adjacent to equipment such as switchboards, panelboards or transformers. The rules in 314.28 are designed to minimize damage to the conductors as they are being installed. The risk of conductor damage where the conductors are installed without compliance with 314.28 is small where the conductor does not extend a long distance from the wireway.
Committee Statement
Resolution: | No substantiation was submitted to show that damage to conductors is unlikely for raceway and cable entry spacings not meeting the requirements of 376.23(B)(1) & (2). |