Type TC cable

Status
Not open for further replies.
Ok, here's another one. Can I install type TC cable in a drywall partition without a raceway?
My biggest concern here is derating, so I'm trying to avoid conduit sleeves between the cable tray and recessed panel.
 
Re: Type TC cable

I don't think so. Look at 336.10(2). It appears that it is only permitted in cable trays or raceways.
Don
 
Re: Type TC cable

I would say no based on the definition. 336.2 Definition. Power and Control Tray Cable, Type TC. A factory assembly of two or more insulated conductors, with or without associated bare or covered grounding conductors, under a nonmetallic jacket, for installation in cable trays, in raceways, or where supported by a messenger wire. :D
 
Re: Type TC cable

Don and Charlie have given the correct "Code" answer. That being said, I think you should try for a 90.4 "special permission."

In the '96 NEC an exception to Section 340-5 was introduced. That exception became what is now 336.10(6). Originally there was a 50' limit. I was involved with several Proposals that extended the limit to 100' and finally an indefinite length.

Type TC is vastly superior to NM; the only reasons that it can't be used the same way is product protectionism - not safety. TC has far better fire retardant and products of combustion performance than NM.

What many folks don't know is that virtually every TC cable also meets the "crush and impact" capabilities of Type MC; NM couldn't begin to. The Type MC "crush and impact" test permits a certain "failure rate." Type TC will pass the test with an "acceptable" UL failure rate. Type MC usually won't fail at all. My most recent argument with CMP7 has been, if they feel the MC standard should be "no failures," they should request a change to the UL product standard. The folks who have opposed TC "open wiring" are the same that oppose making the test more rigorous. (The MC manufacturers). Most MC manufacturers make both but they don't want TC sales cutting into the MC market.

The only problem item is getting the TC "identified." There is no Code requirement that it be listed, labeled, or even "marked" for an open wiring application. I would ask the manufacturer to certify that the cable can pass the MC "crush and impact" test and supply the test data. FedOSHA would accept this. I don't know about local AHJs.
 
Re: Type TC cable

Bob,
Would TC pass all of the requirements for NM? If so could it be dual labled as TC/NM and used for either application?
Don
 
Re: Type TC cable

Originally posted by don_resqcapt19:
Bob,
Would TC pass all of the requirements for NM? If so could it be dual labeled as TC/NM and used for either application?
Don
My "gut" feeling is "yes" to both questions. I'm less familiar with the UL NM specs, but I think a simple read of the "Construction Specification" sections of Art 334 and 336 would confirm that. I think there is still some marketing opposition from the cable manufacturers and they can't be forced to get dual labels.

I still don't have a copy of the '05 NEC, but I have access to the NFPA online version. (Can't "cut and paste" easily :D ) I wasn't involved this cycle, but I noticed that the Section I referenced originally is now 336.10(7) and now requires a specific "TC-ER" mark.

IMO they still have some unnecessary limitations; i.e., "industrial only" and "from tray to utilization equipment."

There has been strong "end-user" demand for the product. The principal opposition is still those who have a vested interest in maintaining the status quo although they are having a tougher time defending it on a "safety" basis each cycle.

Edited for grammar

[ November 22, 2004, 02:20 PM: Message edited by: rbalex ]
 
Status
Not open for further replies.
Top