Use of electric wiring and equipment in plenums. NEC 300.22

[dahualin]

I am confused with NEC 300.22 (B). Could you please explain it? Thanks.

I am doing a project with cooler that using ceiling space as plenum. Can I install any recessed 2x4 fluorescent lights and do I have to install the conduit exposed beneath the ceiling? Can EMT installed in the plenum?

 

[raider1]

I am confused with NEC 300.22 (B). Could you please explain it? Thanks.

I am doing a project with cooler that using ceiling space as plenum. Can I install any recessed 2x4 fluorescent lights and do I have to install the conduit exposed beneath the ceiling? Can EMT installed in the plenum?

I would say that the above portion of a drop ceiling that is used for return air is really "Other Space Used for Enviromental Air" in accordance with 300.22(C) and not a "Duct or Plenum used for enviromental air" as per 300.22(B).

With that said you can use EMT conduit and install 2X4 fluorescent lights in accordance with 300.22(C)(1) and (2) respectively.

Chris

 

[haskindm]

For what it is worth, I agree with Chris.