Plenum connection?

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mlahner

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I have been requested to supply a large quantity of lighting fixtures with fmc or other whips and disconnects to be installed in a plenum. The lighting fixtures will not be in the plenum but the requested disconnect will be. It is a large commercial project and will require code compliance. I know no code compliant method to provide a plenum rated disconnect or male / female whip for power (120v/277v). Does a solution exist?
 
Do you know of a Code section which prohibits a disconnect in a plenum?

Exactly what type of plenum are we talking? One specifically designed for handling environmental air, or not, such as above a typical commercial suspended ceiling that is used for air return.
 
Smart $ said:
Do you know of a Code section which prohibits a disconnect in a plenum?

Exactly what type of plenum are we talking? One specifically designed for handling environmental air, or not, such as above a typical commercial suspended ceiling that is used for air return.
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The plenum is for return air, typical for many commercial buildings. Section 410.62(c)2a. requires that the cord in a cord connected fixture must be visible for it's entire length. This application would have much / most of the "cord" located in the plenum.
 
mlahner said:
The plenum is for return air, typical for many commercial buildings. Section 410.62(c)2a. requires that the cord in a cord connected fixture must be visible for it's entire length. This application would have much / most of the "cord" located in the plenum.
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FMC / MC whips are not cords. Where is the disconnect requirement? Fluorescent ballasts, yes. LED, I do not believe so. Are these just customer requests that you are referring to?
 
mlahner said:
The plenum is for return air, typical for many commercial buildings. Section 410.62(c)2a. requires that the cord in a cord connected fixture must be visible for it's entire length. This application would have much / most of the "cord" located in the plenum.
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I am still not sure you are clear on the distinction between two types of air handling space.
If a closed "duct" or space is created just for the purpose or air handling it is a plenum. One example would be if half of an attic space above an office or work floor was partitioned off to cover air return ducts along one side of the space. Constructed for the purpose ---> plenum. Access would be by door(s) or hatches for that purpose.
If the space above a dropped ceiling has return air vents is some tile locations that do not connect to ductwork and large return air vents somewhere that suck from that space, it is an "environmental air handling space", not a plenum.
That said, many NEC restrictions apply to both air spaces and plenums.
 
Yes, this will not be a duct constructed for the purpose so it will be an air handling space. The disconnect requirement is from the architect to allow access to roller shades mounted above.

So what type of male / female plug or disconnect would be acceptable on an FMC cable used in an air handling space?
 
mlahner said:
Yes, this will not be a duct constructed for the purpose so it will be an air handling space. The disconnect requirement is from the architect to allow access to roller shades mounted above.

So what type of male / female plug or disconnect would be acceptable on an FMC cable used in an air handling space?
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I do not know of any that are listed or identified for FMC termination. I believe you are looking at installing switches in the j-box (device box) to which you connect the whip. RFI the architect. Apparently, he doesn't know Code as well as he thinks.
 
mlahner said:
I have been requested to supply a large quantity of lighting fixtures with fmc or other whips and disconnects to be installed in a plenum. The lighting fixtures will not be in the plenum but the requested disconnect will be. It is a large commercial project and will require code compliance. I know no code compliant method to provide a plenum rated disconnect or male / female whip for power (120v/277v). Does a solution exist?
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Not sure if they're plenum rated, but the Reloc line of connectors come with FMC whips:

http://www.acuitybrands.com/products/lighting/indoor/modular-wiring#t=Products

Their website is a trainwreck, and I can't tell exactly what you'd need to build a connectorized solution. Probably best to call them on Monday.


SceneryDriver
 
SceneryDriver said:
Not sure if they're plenum rated, but the Reloc line of connectors come with FMC whips...
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Forgot all about RELOC. Probably because OP said FMC was spec'd and I consider RELOC whips as MC. I don't know if their whips are plenum rated either, but I have installed gobs of them in plenum locations. :blink:

Being more than just a wiring method, compliance with 300.22(C)(3) is required. While the connectors essentially form a metallic enclosure around the connection, what about when disconnected?
 
I don't see why MC would be an issue. As to what about being disconnected, I assume they would normally be connected and only disconnected for maintenance of the shades. (Though I think there should be a better way to do that without disconnecting building wiring.)

-Hal
 
hbiss said:
I don't see why MC would be an issue. As to what about being disconnected, I assume they would normally be connected and only disconnected for maintenance of the shades. (Though I think there should be a better way to do that without disconnecting building wiring.)

-Hal
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Not the MC that I question, or the metal connectors when connected. It is exposure of the non-metallic parts of the connector when disconnected. I would think exposed parts have to meet the same requirements as a nonmetallic enclosure. See IN in 300.22(C)(3).

I understand one would think the connectors would only be disconnected for maintenance. So? What if disconnected for other reasons? What if a fire breaks out while performing said maintenance? What ifs are all we get before it actually happens.
 
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