Code Q&A: Conductor Feed Through

Q. What are the requirements when running conductors through one panel cabinet to feed another panel?

A. Cabinets, cutout boxes, and meter socket enclosures can be used for conductors as feeding through, spliced, or tapping off to other enclosures, switches, or overcurrent devices where all of the following conditions are met [312.8]:

• The total area of the conductors at any cross section doesn't exceed 40% of the cross-sectional area of the space.
• The total area of conductors, splices, and taps installed at any cross section doesn't exceed 75% of the cross-sectional area of that space.
• A warning label on the enclosure identifies the disconnecting means for feed-through conductors.