Q. When can power distribution blocks be installed in junction boxes?
A. Power distribution blocks installed in junction boxes over 100 cu. in. must comply with the following [314.28(E)], as shown in the Figure:
Installation. Be listed as a power distribution block.
Size. Be installed in a box not smaller than required by the installation instructions of the power distribution block.
Wire-bending space. The junction box is sized so that the wire-bending space requirements of 312.6 can be met.
Live parts. Exposed live parts on the power distribution block aren't present when the junction box cover is removed.
Through conductors. Where the junction box has conductors that don't terminate on the power distribution block(s), the through conductors must be arranged so the power distribution block terminals are unobstructed following installation.