Is direct burial wire duct rated?

Here is the situation; I have a 200 amp breaker box on the north (2 story) side of my home with lots of unused circuits. The 1 story south end of the home is wired through a 4 circuit sub-panel, this is inadequate for today's needs. I want to pull 10 ga wires through an abandoned hvac duct, to add circuits to the one story as that is the shortest path and it runs completely through the 2 story between the floors north and south. An electrician told me I can't use romex because it is not duct rated. I have a couple hundred ft. of 10-3 w/ground direct burial that I used as a temporary to my shop never really buried, just strung across the field. It appears to be still in good shape, just dirty. I'm assuming I can't use non duct rated because I might not be the last person here and someone may actually try to use the duct for a duct. Not that it ever worked, it was a bad idea in the first place, the main hvac unit never had enough umph to push air that far, and before I got here the previous owner had zoned the 2 story with window units, and I upgraded that to PTACs.

Reply to
Eric in North TX
Loading thread data ...

The terminology is "plenum rated" wire. It has to do with the insulation on the wire, its smoke and fire contribution in a fire. Plenum rating is most often used on Cat 5, twisted pair, and other light gauge control/alarm/electronic type wiring. Plenum rated wire is more expensive.

I do not know if direct bury cable is plenum rated.

Reply to
DanG

No you can't. UF has still a PVC jacket and that is not plenum rated. In fact you really can't use ducts for wiring except for wiring necessary for the HVAC itself like a damper system.

Reply to
gfretwell

Suppose I ran it in conduit and blocked off the connection to all other hvac runs, would that get it?

Reply to
Eric in North TX

If there is a solid metal between the wire and all the air-handling spaces, you're ok, yes. EMT is sufficient, I don't think that spiral wrapped stuff is.

Reply to
Goedjn

Eric in North TX posted for all of us...

Greg Fretwell gave the straight dope but look at it this way. The run is delineated for you so you could run it alongside the HVAC duct.

Reply to
Tekkie®

As long as the duct is not in use for environmental air then you can run any wire you want to use that may be used in that type of building. You can use type AC or type MC cable in a plenum ceiling. The use of Type AC or Type MC cable would only be to guard against any return of that void space to service as an air duct.

What wiring method was used to supply the sub panel? If it is conduit you could investigate the possibility of a re pull with larger conductors and replace the existing feeder supplied panel with a larger one.

Reply to
Tom Horne, Electrician

Unfortunately, that isn't a good option. The existing sub-panel is across a hall from the end wall of the addition, so running the circuit wires would be a bear especially since the peak of the one story roof is only about 2 ft above the dividing floor of the 2 story and the box is 10 ' into the structure and to the left of the line-up of the attic and celing / floor. the wires that are run appear to have been run during construction. And the feed for the sub panel as well seems to have been run before the second floor was decked or before the downstairs was dry walled no conduit. The cleanest seems to run a new sub panel feed in conduit and put a sub panel on the second floor, then totally rewire the 1 story splitting the circuits especially the kitchen/laundry room.

Reply to
Eric in North TX

i suggest you use 6/3 bx. bx because its protected from any mechanical damage. if you look at the wire feeding your furnace or hot water tank, it should be bx because its in direct contact with metal. if the duct is abandoned then "plenom" rated is not needed.

6/3 because it will allow you to install a 60 amp. sub panel.
Reply to
matt

HomeOwnersHub website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.