Q. According to the 2005 NEC (not any specific state or local code), when installing 2-foot by 4-foot fluorescent lay-in luminaires in suspended ceilings, how many corners of any one of the luminaires require an independent support wire to support it?

  1. All four corners.
  2. On any two opposite corners.
  3. On any two corners. The support does have to be on opposite corners.
  4. There is no requirement for independent support wires for this application as written.

Answer: D

There is no requirement for independent support wires for this application as written. [See 410.16(C)] However, some states, such as California, and some municipalities (check Chicago, Louisville, Ky., Charleston, S.C., Frankfort, Ky., and others) may have specific requirements for independent support for luminaires installed in suspended ceilings.

Owen is the owner and president of National Code Seminars and the holder of master electrician certifications in 46 states. He can be reached at necexpert@aol.com.