ing a grounded conductor
in an individual terminal that is
used for another conductor. This includes
equipment grounding conductors that
may be terminated on the same terminal
strip in service equipment. This installation requirement ensures that, where
there is a need to do justified energized
work and a grounded/neutral conductor
is removed, it is the only conductor under
For example, if two branch circuits have
neutral conductors terminated under the
same screw and one needs to be removed,
both circuits must be de-energized or
serious hazards will occur where the
grounded/neutral conductor of an energized circuit is removed. Equipment
may also be damaged where a multiwire branch circuit’s grounded/neutral
conductor is removed while the branch
circuit is energized.
Cable tray listing and bonding
The designing engineer on a new
project requires the cable tray for a
communications system to be listed and
bonded. I understand that the cable tray
system needs to be bonded. The engineer
claims that all raceways containing
communications circuits must be listed.
That is not an issue because the cable tray
system we are installing is listed. Does a
cable tray installation that contains only
communications circuits need to be listed?
How would we size the bonding jumpers
where there are separations in the cable tray
for communications circuits?
There are no requirements in articles 392
and 800, or elsewhere in the NEC, that
would require cable tray to be listed. Section 800.182 requires communications
raceways and cable routing assemblies to
be listed, not cable tray.
A common misunderstanding throughout the industry is that cable tray is a
raceway. It is instead a support system for
raceways, conductors, cable assemblies
and cable. Section 392.60(A) requires
metal cable tray containing only nonpower
conductors to be electrically continuous
through approved connections or the
use of a bonding jumper. In this application, the cable tray is not being used as an
DOLLARD is the safety coordinator for IBEW Local No. 98 in Philadelphia and works closely with
contractors to ensure job-site safety and compliance with all installation codes and standards. He is
a member of the NEC Correlating Committee, NEC CMP- 10, NEC CMP- 13, NFPA 70E, NFPA 90A/B and
the UL Electrical Council. He can be reached at email@example.com.
equipment grounding conductor. The only
requirement is for the tray to be electri-
cally continuous. The NEC does not have
prescriptive requirements for sizing the
bonding jumpers for cable tray containing
only nonpower conductors.
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