article 300.22 clarification

[SteveLaorenza]

I need clarification on wiring in a dwelling unit, can I install wires in these plenum spaces for a switch and install a wall sconce in same place? The plenums are the joist bay in basement and interior petition on the first floor.

 

[tom baker]

Is this a return air for a furnace?
If so there are restrictions.

 

[infinity]

I need clarification on wiring in a dwelling unit, can I install wires in these plenum spaces for a switch and install a wall sconce in same place? The plenums are the joist bay in basement and interior petition on the first floor.

What type of wiring? NM cable can only pass horizontally through the return air space and cannot run up through the partition.

 

[tom baker]

See 300.21 C exception

 

[SteveLaorenza]

Is this a return air for a furnace?
If so there are restrictions.

Yes it is return air for heating and AC.

 

[SteveLaorenza]

What type of wiring? NM cable can only pass horizontally through the return air space and cannot run up through the partition.

Can MC cable be used in this space?

 

[SteveLaorenza]

See 300.21 C exception

I did read the exception but was still not sure if a dwelling was exempt.

 

[infinity]

Can MC cable be used in this space?

Yes the horizontal limitation is for NM cable.

 

[tom baker]

Panning joist for return air is common in older dwelling units.

 

[SteveLaorenza]

What type of wiring? NM cable can only pass horizontally through the return air space and cannot run up through the partition.

Thanks for the help with this article.