type tc in class1 div 2

[weressl]

These are slick, but don't get me from a conduit to a box or tray. I would prefer to not leave much exposed cable outside of the tray as I'm sure these operators are capable of trashing it somehow. Also, we'll be running some 100 hp motors @ 480 volts, so these and other power cables will create quite a hazard.

Too bad there isn't an electricaly rated expanding foam!!

Up to 200HP is usually TC-ER cable and there is a 2-3' exposed length of cable between the cable channel or basket tray riser to the pecker-head.

Larger than 200HP motors are MV and the cables are usually CLX or armored/jacketed and exposed the same way as above.

"II. Installation
336.10 Uses Permitted.​

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Type TC cable shall be permitted
to be used as follows:
.....
(7) In industrial establishments where the conditions of
maintenance and supervision ensure that only qualified
persons service the installation, and where the cable is
continuously supported and protected against physical
damage using mechanical protection, such as struts,
angles, or channels, Type TC tray cable that complies
with the crush and impact requirements of Type MC
cable and is identified for such use with the marking
Type TC?ER shall be permitted between a cable tray
and the utilization equipment or device. The cable shall
be secured at intervals not exceeding 1.8 m (6 ft).
Equipment grounding for the utilization equipment
shall be provided by an equipment grounding conductor
within the cable. ........"​

 

[wyo1]

Maybe I haven't been clear enough here. The tray cable is dropping to junction boxes used as termination points (nothing but term blocks and pdb's) and from there to motors, instruments, etc., everything is run in grc and sealtight.

Personally, I would never run a tray cable exposed (rated or not) to a motor or instrument anywhere near an area a mechanic may have to work on something. I don't care what kind of connector you run it through, it will still most likely get stepped on, pulled out of peckerhead, cut. The only time we do this is when using type tc-hl or coated mc (anything with a metal sheath).

 

[weressl]

Maybe I haven't been clear enough here. The tray cable is dropping to junction boxes used as termination points (nothing but term blocks and pdb's) and from there to motors, instruments, etc., everything is run in grc and sealtight.

Personally, I would never run a tray cable exposed (rated or not) to a motor or instrument anywhere near an area a mechanic may have to work on something. I don't care what kind of connector you run it through, it will still most likely get stepped on, pulled out of peckerhead, cut. The only time we do this is when using type tc-hl or coated mc (anything with a metal sheath).

It seems like that the JB introduces another termination point and that is another point of failure and adding to the cost of installation.

Sealtight breaks, pulls out not unlike the TC. The installation method has been in use for 40 years with no recorded higher incident rate than any others. On the contrary, people would sooner step on a conduit to reach somewhere than on a cable.

 

[wyo1]

It seems like that the JB introduces another termination point and that is another point of failure and adding to the cost of installation.

Sealtight breaks, pulls out not unlike the TC. The installation method has been in use for 40 years with no recorded higher incident rate than any others. On the contrary, people would sooner step on a conduit to reach somewhere than on a cable.

The jb's are necessary to facilitate the removal of unclassified panels that came with the skids that are in a classified area. (Would have been pretty extensive and pricy rewiring the whole thing.) Point taken on the sealtight, maybe I'm just old fashioned that way.

I still have to respectfully disagree with your assumption that a guy needs the cgb's at the conduit end, but I will probably use them outside to keep water out of the boxes.

Thanks for the info.

 

[ontherox21]

Dux seal is no different than duct tape, with the exception that duct tape IS developed and approved to seal minute air-leaks in a crimped sheet-metal duct-work.

Dux seal compound is a temporary repair, fix in my book I would never use it for permanent installation. On the other hand my industry maybe subject to much harsher conditions than others. I just know what works and what isn't. Although it is resistant to shrinking it is not immune to it. Let me know if you intend to have a maintenance program going along with that to check for leaky patches.:grin:

As the profit pressures grow and the available workforce shrinks our primary objective is to minimize installations that require attention. Usually complex machinery, switchgear and control systems are much more complex and requiring higher skill so I wouldn't want to insult our skileld technicians to look for leaky seals.

I like to specify and use devices that are designed for the specific purpose, and select the best design for that specific use and refrain from inventive 'other uses'. I believe for example that the best multicoinductor sealing product is made by Roxtec. http://www.roxtec.com/ Even though it is an offshore product, it is superior in performance and flexibility to the other US made ones.

Thank you for your kind words. I'm the regional manager for Roxtec in Texas and not to push the product or anything, but if you have questions concerning entering multiple cables into a box or building I'd be more than happy to assist. Feel free to PM me.