Use of TC-ER cable outside cable trays

[EK001]

Hi Everyone,

I would like to get your thoughts on a few questions surrounding the use of TC-ER cable as permitted by NEC 336.10.

• If a TC-ER exits a tray to connect to a device/equipment, 336.10 (7) c) mentions that it should be continuously supported. 336.10 (7) e) also goes on to say that the cable must be secured every 6 ft or less. I have seen installations where TC-ER cable exits a tray and goes several feet to equipment without a strut/channel as it's not practical. Is this correct? Are they using the Exception to (7) rule which allows TC-ER cables to extend without continuous support upto 6ft?
  
  
• What is the point of having an -ER (-Exposed Run) classification per UL 1277 where the cable has to meet impact and crush tests similar to MC cables if it can only run a max of 6ft without continuous support?
  
  
• Further to the 'Exception to (7)' rule, what if a TC-ER cable (in industrial / commercial applications) exits a tray and is longer than 6ft without continuous support? Is this simply not allowed? What if it is supported/secured by brackets / clips every few feet and installed on a wall but not in a channel / strut?
  
  
• Is there any way a TC-ER cable can be installed without any tray anywhere and is simply installed on a wall using special brackets? I ask because I am seeing new proprietary flat cables that are TC-ER rated and meant for installation on a wall directly.

Thank you.

 

[shortcircuit2]

Exposed run classification is for the cable installed in a tray...exposed.

There is quite a laundry list of requirements in 338.10(7) which includes "industrial establishments" in b.

Focus on 338.12 uses not permitted in (1) and (2)...here is where it usually ends up with physical protection by means of a raceway when not in the tray.

 

[roger]

Exposed run classification is for the cable installed in a tray...exposed.

There is quite a laundry list of requirements in 338.10(7) which includes "industrial establishments" in b.

Focus on 338.12 uses not permitted in (1) and (2)...here is where it usually ends up with physical protection by means of a raceway when not in the tray.

I think you have a typo and mean 336.

 

[winnie]

I could see value for expanded use of TC-ER-JP in residential applications. Allowed inside and outside, easier to strip than UF, and can otherwise be used like NM. (Limited to 1 and 2 family homes)

 

[shortcircuit2]

I think you have a typo and mean 336.

Geez...having a rough day. Thanks!

 

[Mr. Serious]

I believe the NEC allows it to be installed underground. The actual wording says it still has to be in a tray, but that's ridiculous. I'm mostly sure that they meant it can be outside of a tray if it's installed underground.

 

[Mr. Serious]

The actual wording says it still has to be in a tray, but that's ridiculous. I'm mostly sure that they meant it can be outside of a tray if it's installed underground.

Maybe that was the 2014 code. The 2020 one seems clear that it doesn't have to be in a tray if it's underground. I have both books and don't remember which one I was reading last time.