Receptacles in plenum ceilings for motorized shades

[Junior_EE]

Similar questions have been asked in the past on this forum, but are slightly different than my question, and they are possibly outdated. This question pertains to NEC 2011.

We are connecting motorized shades in classrooms to power. Each shade comes with a local power supply that connects to power via a receptacle and plug/cord connection. Each classroom has a drop ceiling that is being used as a plenum. Two questions:

1.) Can I install a duplex receptacle above the drop ceiling for the motorized shades? I don't see anything in article 300.22 that precludes this.

2.) In most cases, according to article 400.8, using a flexible cord above a drop ceiling is not permitted. However, would flexible cords be allowed for motorized shades as per 400.7(A)(9), i.e. because the shades are considered "connection of moving parts"?

 

[don_resqcapt19]

The power supply is not a moving part.

 

[Junior_EE]

The power supply is not a moving part.

So what would be acceptable under this section? The motor for the shade is a moving part.

 

[don_resqcapt19]

So what would be acceptable under this section? The motor for the shade is a moving part.

The motor itself physically moves? Or does the motor shaft turn and move something else?

It would be my opinion that you need to select a motorized shade that can be hard wired using one of the wiring methods in 300.22(C). I don't see anything in 300.22(C) that would permit the use of any cord or cable that is not specifically listed for use in a 300.22(C) space.

 

[LarryFine]

So what would be acceptable under this section?

Either the face of the receptacle and the cord below the ceiling, or a power supply that has no 120v cord.

 

[Junior_EE]

Either the face of the receptacle and the cord below the ceiling, or a power supply that has no 120v cord.

I meant what would be considered "connection of moving parts" and, therefore, acceptable by code. If it doesn't mean something like motorized shades, I guess I don't understand what sort of situation that use under 400.7(A)(9) was intended for.

 

[LarryFine]

They mean where the equipment itself moves while in operation, requiring a flexible means of connection.

Unless the point where the supply enters the equipment must move around, it doesn't require flexibility.

 

[Junior_EE]

They mean where the equipment itself moves while in operation, requiring a flexible means of connection.

Unless the point where the supply enters the equipment must move around, it doesn't require flexibility.

The power supply plug uses an AC/DC adapter at the plug-in location, where it converts 120VAC to 24VDC. Is it okay to run this low voltage wiring above the drop ceiling? I should have mentioned that it is not a 120VAC flexible cord.

If so, is it also okay to have the receptacle above the ceiling if it is an HVAC plenum, i.e. question #1 above?

 

[tom baker]

Can the recpt be mounted to a t bar hanger so the face is flush with bottom of tile?

 

[LarryFine]

Can the recpt be mounted to a t bar hanger so the face is flush with bottom of tile?

Absolutely.

Or do you mean in this specific instance?

 

[LarryFine]

Is it okay to run this low voltage wiring above the drop ceiling?

Yes.

If so, is it also okay to have the receptacle above the ceiling if it is an HVAC plenum, i.e. question #1 above?

That I don't know.

 

[Mdsparky]

would this power supply fly ?

 

[don_resqcapt19]

The power supply plug uses an AC/DC adapter at the plug-in location, where it converts 120VAC to 24VDC. Is it okay to run this low voltage wiring above the drop ceiling? I should have mentioned that it is not a 120VAC flexible cord.

If so, is it also okay to have the receptacle above the ceiling if it is an HVAC plenum, i.e. question #1 above?

No matter what the voltage or function of the cord or cable is, it cannot be in a 300.22(C) area unless specifically listed for use within an air-handling space.

 

[LarryFine]

would this power supply fly ?

What Don just said above.

 

[hbiss]

In most cases, according to article 400.8, using a flexible cord above a drop ceiling is not permitted.

Exactly what cord or cable is provided? Is it actually a flexible cord or is it a cable. Look at it and tell us what it says on it. My hunch is that because this is an air handling space you are going to have to replace whatever it is with a CL2 plenum listed cable- which means taking the shades apart.

Can I install a duplex receptacle above the drop ceiling for the motorized shades?

You can install a receptacle above a drop ceiling but you can't plug anything into it.

I believe you can locate a hard wired power supply made with a metal cabinet up in the ceiling such as would be used for alarms and access systems. Size and use it to power several shades.

-Hal

 

[augie47]

Someone get me back on track !
I have not read where it is an air plenum ceiling and even then Class 2 wiring can be installed if it complies with 725.154.
Where am I going wrong ?

 

[retirede]

Someone get me back on track !
I have not read where it is an air plenum ceiling and even then Class 2 wiring can be installed if it complies with 725.154.
Where am I going wrong ?

Thread title states “plenum ceiling.”

 

[augie47]

Thread title states “plenum ceiling.”

Damned old age ! Thanks

 

[don_resqcapt19]

Someone get me back on track !
I have not read where it is an air plenum ceiling and even then Class 2 wiring can be installed if it complies with 725.154.
Where am I going wrong ?

725.154 and 300.22(C) require the same thing, but I really doubt that the cables and cords associated with this equipment will be in compliance.

 

[NTesla76]

I believe you can locate a hard wired power supply made with a metal cabinet up in the ceiling such as would be used for alarms and access systems. Size and use it to power several shades.

-Hal

This.