State the code for running exposed THHN

[bcnj]

Im in a situation where I am being asked to state the code section that does not allow the Eposed use of THHN wiring. The previous electrician or handyman ran 277v THHN to a low voltage 24v transformer. This is clearly going to have to get ripped out but I am actually having a tough time providing the code section.

Here is what I have.

300.3(A) Single Conductors - Single conductors specified in Table 310.104(A) shall only be installed where part of a recognized wiring method of Chapter 3.

 

[augie47]

Is the exposed THHN on the 24v side of the transformer ?

 

[luckylerado]

Im in a situation where I am being asked to state the code section that does not allow the Eposed use of THHN wiring. The previous electrician or handyman ran 277v THHN to a low voltage 24v transformer. This is clearly going to have to get ripped out but I am actually having a tough time providing the code section.

Here is what I have.

300.3(A) Single Conductors - Single conductors specified in Table 310.104(A) shall only be installed where part of a recognized wiring method of Chapter 3.

I think you nailed it.

 

[augie47]

I think you nailed it.

If the conductor was installed as Class 2 Art 725 wiring I does not appear 300.2 would apply.

 

[bcnj]

277v exposed thhn on the line side. Only problem with 300.03A is that I can't find where it says you can't run thhn exposed.


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[steve66]

310.10 - the conductors described in 310.104 shall be permitted for use IN any of the wiring methods covered in Chapter 3 and as specified in their respective tables, or as permitted elsewhere.

 

[augie47]

310.10 - the conductors described in 310.104 shall be permitted for use IN any of the wiring methods covered in Chapter 3 and as specified in their respective tables, or as permitted elsewhere.

That pretty much sums it up. There are very limited areas where the open conductors can be used such as Art 398.

 

[JFletcher]

277v exposed thhn on the line side. Only problem with 300.03A is that I can't find where it says you can't run thhn exposed.


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It doesnt say that directly. What it does say is "...shall only be installed where part of a recognized wiring method of chapter 3". There is no such section.

Also, 300.3(B) would be a violation here as well since the individual THHN are not in the same raceway, aux gutter, cable tray, cable or cord, I presume.