wire trays or raceways in residential

[backwaterdogs]

I can't find anything directly prohibiting this, but a customer doesn't want any holes drill through their floor joists and very, very particular about having organized wires and wants me to use something like a wire tray(used many times in computer cable management - kind of looks like a ladder).

Anyway, the customer wants to suspend the wiretray below the joists and then have all the cable laid on the tray, then run paralell with the joist when going through the floor.

Anything wrong with this or does anyone have a alternative to drilling through joists that is compliant? I thought about suggesting using 4 pvc as conduit, but sure that would be to code either.

thanks

 

[iwire]

The first issue is that NM must be marked as suitable for cable tray use if you want to install it that way.

334.10 Uses Permitted.
Type NM, Type NMC, and Type NMS cables shall be permitted to be used in the following:

(4) Cable trays, where the cables are identified for the use.

I have never looked to see if the NM I get is identified for cable tray use.

 

[RAM460]

When we first started doing new homes, the builder did not want to see a big wad of wires in the basement. So we took probably 90 + % of the circuits up out of the panel in to the walls and fed them to their required areas. He understood that it was more expensive, to him it was worth it. We too it one step farther, being commercial/ industrial contractors we decided to run like 3/4" conduit in the basement to pick up all the basement wiring such as lights, plugs, furnace, sump pump, etc... He loved it..

Just a thought
Roger

 

[larryl]

cable tray

cable tray

nail up a running board,under the joists,2x10,,
or if you really wanna go for it, a wide peice of pine,painted,,

 

[tbonse]

Backwaterdogs, I'm not so sure about the wiretray idea, however conduit is perfectely acceptable, and certainly meets the requirement of conductor protection. My local AHJ has been nothing if not happy that I am using conduit in this situation. I, however, am doing an electrical upgrade/update of the entire electrical system in this house and therefore have opted to use EMT for running all the wires in the house, as this has old rough hewn timbers (mostly hardwoods) and plaster walls. As such, I have already snapped two holesaw bits in half just to run the structured wiring (and I'm not even done with that). This method also eliminates the need for installing steel plates on the studs, as I would've had to do with NM.

 

[tbonse]

As a continuation of my last thought, should you decide to use conduit (of any type, be it rigid, EMT, or rigid non-metalic ie pvc), you will still have to abide by the derating and conduit fill requirements. See 300.15 (B)(2)(a), all of 310, as well as the appropriate section from 320 to 362 depending on which cable/conduit you chose to utilize. Or if you chose to use a wireway, articles 376, 378, 384, 386, 388, 392. I am however unfamiliar with using wireways. Article 392, may be more to what you are looking for and 392.3(A) does include NM cable as a possible participant in a cable tray system, but you will definately need to read further and/or talk to your AHJ before designing the electrical system based off of this information.

 

[iwire]

My local AHJ has been nothing if not happy that I am using conduit in this situation. I, however, am doing an electrical upgrade/update of the entire electrical system in this house and therefore have opted to use EMT for running all the wires in the house,

tbonse, I am confused.

Are you doing this work?

That seems odd as you list your occupation as Data Translations Technician (telecom).

Are you also an electrician?

Bob