Strapping to ceiling grid

[badashuka]

When installing a commercial lighting system I have been told to never attach my electrical system to any ceiling wire attached to the grid unless it is supporting my light. Now I am being told to attach all my mc strapped and juntion boxes to the main run in the grid instead of floating them. I have searched my code book and cannot find an answer. Hoping you can help again in answering my question.

:-?

 

[Volta]

When installing a commercial lighting system I have been told to never attach my electrical system to any ceiling wire attached to the grid unless it is supporting my light.

True, commercial or not, but Section 310.11(A) allow us to use wires "that are installed in addition to the ceiling grid support wires".

Now I am being told to attach all my mc strapped and juntion boxes to the main run in the grid instead of floating them.

Same section tells you that you can't support those items by the ceiling grid. You can't 'float' equipment either, unless it is lighter than the surrounding medium. :roll:

I have searched my code book and cannot find an answer. Hoping you can help again in answering my question.

:-?

The luminaire is allowed to be supported by the securely attached grid, but must be securely fastened to it 410.36(B). Additional support wires may be a building code, not NEC.

 

[mdj1320]

for the support of your electrical boxes and mc you must install your own ceiling grid wires must be attached to the deck or building steel.at one end and attached to grid or light fixture .but you must identify your wire from the grid guys wire .(by painting the wire or tagging with tape ).

 

[infinity]

Take look here:

300.11 Securing and Supporting.
(A) Secured in Place. Raceways, cable assemblies, boxes, cabinets, and fittings shall be securely fastened in place. Support wires that do not provide secure support shall not be permitted as the sole support. Support wires and associated fittings that provide secure support and that are installed in addition to the ceiling grid support wires shall be permitted as the sole support. Where independent support wires are used, they shall be secured at both ends. Cables and raceways shall not be supported by ceiling grids.
(1) Fire-Rated Assemblies. Wiring located within the cavity of a fire-rated floor?ceiling or roof?ceiling assembly shall not be secured to, or supported by, the ceiling assembly, including the ceiling support wires. An independent means of secure support shall be provided and shall be permitted to be attached to the assembly. Where independent support wires are used, they shall be distinguishable by color, tagging, or other effective means from those that are part of the fire-rated design.
Exception: The ceiling support system shall be permitted to support wiring and equipment that have been tested as part of the fire-rated assembly.
FPN: One method of determining fire rating is testing in accordance with NFPA 251-2006, Standard Methods of Tests of Fire Resistance of Building Construction and Materials.
(2) Non?Fire-Rated Assemblies. Wiring located within the cavity of a non?fire-rated floor?ceiling or roof?ceiling assembly shall not be secured to, or supported by, the ceiling assembly, including the ceiling support wires. An independent means of secure support shall be provided and shall be permitted to be attached to the assembly.
Exception: The ceiling support system shall be permitted to support branch-circuit wiring and associated equipment where installed in accordance with the ceiling system manufacturer?s instructions.

 

[cadpoint]

... Now I am being told to attach all my mc strapped and juntion boxes to the main run in the grid instead of floating them. ...:-?

Don't forget that your luminary could possibly be listed as a raceway thus no floating junction boxes at all.

Frankly I’m thinking more of the 2 x4 variety where the trough offers more space. It can’t hurt to know
the full aspects of what your light might offer…