Class 2 Wiring in walls

[Dennis Alwon]

Got this from a new member

Hi Dennis,
Does the NEC address Class 2 wiring, specifically can I feed Class 2 Wiring in Dry Wall without conduit.

Thanks,
Matt

My response is in general yes if you use class 2 wiring but in Chicago I have no idea.

 

[GoldDigger]

Got this from a new member



My response is in general yes if you use class 2 wiring but in Chicago I have no idea.

Not all Class 2 rated wiring types are approved for concealed use in walls. One example of this is landscape wire (unless dual listed as another type.)

 

[hbiss]

The cable would have to be listed CL2 or CL2/CM etc. Can't use zip cord or anything else not listed. I assume the question is from somebody from the Chicago area. Don't quote me but I think even CL2 and needs to be in conduit.

Not all Class 2 rated wiring types are approved for concealed use in walls.

Are you sure about that? There is landscape wiring with no listing and that cannot be run within structures. If it has a CL2 listing it can. I believe that's what you are thinking about.

-Hal

 

[Dennis Alwon]

Not all Class 2 rated wiring types are approved for concealed use in walls. One example of this is landscape wire (unless dual listed as another type.)

I did say in general

 

[Dennis Alwon]

Are you sure about that? There is landscape wiring with no listing and that cannot be run within structures. If it has a CL2 listing it can. I believe that's what you are thinking about.

-Hal

Most underground landscape does not have a vertical flame rating and cannot enter the dwelling. This means even in a crawl space, IMO

 

[Matthew Wnek]

Got this from a new member



My response is in general yes if you use class 2 wiring but in Chicago I have no idea.

Where is that stated in the NEC Handbook, i.e., Article Reference. I understand the local code would be a whole other story.

 

[hbiss]

Most underground landscape does not have a vertical flame rating and cannot enter the dwelling. This means even in a crawl space, IMO

That's why it doesn't say CL2 on it.

Where is that stated in the NEC Handbook, i.e., Article Reference.

725.179

-Hal

 

[Dennis Alwon]

article 411 also talks of class 2 wiring. Art 411 is not 1 page long and causing more anguish for it size than any other IMO.

 

[GoldDigger]

article 411 also talks of class 2 wiring. Art 411 is not 1 page long and causing more anguish for it size than any other IMO.

Some problems that I have with both of them in combination is that
1. they both can make use of a Class 2 power supply, and an Article 411 system may also meet the definition of an Article 725 Class 2 system.
2. There is a confusion when looking at people's questions on the subject between a Class 2 wiring method, a method allowable for use in a Class 2 or 411 system (which includes a lot of Article 300 methods), and Class 2 wire and cable (a specific wire type, not a wiring method.)

 

[hbiss]

411 shouldn't be confusing as it was written to address LV interior lighting. There is nothing there that isn't in 725, 411 just spells it out for you and adds some other restrictions specific to those lighting installations and those restrictions have nothing to do with 725.

There is a confusion when looking at people's questions on the subject between a Class 2 wiring method, a method allowable for use in a Class 2 or 411 system (which includes a lot of Article 300 methods), and Class 2 wire and cable (a specific wire type, not a wiring method.)

Class 2 is a wiring method just as Class 1 is. Read 725. If a LV system is class 2 it can use class 2 wiring methods. If the LV system is not class 2 (or class 3) it is class 1 and must use a chapter 3 wiring method. That's all 411 says in that regard and it comes directly from 725.

-Hal

 

[GoldDigger]

Class 2 is a wiring method just as Class 1 is. Read 725.
-Hal

Meant to say that CL2 is a wire type, and that some people consider that it stands for "class 2".

 

[don_resqcapt19]

...
Class 2 is a wiring method just as Class 1 is. ...
-Hal

If Class 1 is a wiring method, then why does section 725.46 exist? Class 1, 2, and 3 are types of circuits, not wiring methods. When you look at 725.130, it is less clear that the Classes are not wiring methods, because of the permission to use low voltage cables as the wiring method, but just because you can use CL2 cable as the wiring method for a Class 2 system or circuit, does not mean that Class 2 is a wiring method.

 

[kwired]

If Class 1 is a wiring method, then why does section 725.46 exist? Class 1, 2, and 3 are types of circuits, not wiring methods. When you look at 725.130, it is less clear that the Classes are not wiring methods, because of the permission to use low voltage cables as the wiring method, but just because you can use CL2 cable as the wiring method for a Class 2 system or circuit, does not mean that Class 2 is a wiring method.

I agree. Nothing prevents you from using a chapter 3 raceway and 600 volt conductors for class 2 circuits, but you can not use a CL2 marked cable for power and lighting unless same cable also has appropriate markings for the application - which is very unlikely.

Get into hazardous locations and you very well may be using raceway wiring methods (primarily RMC/IMC) for class 2 circuits.

 

[hbiss]

If Class 1 is a wiring method, then why does section 725.46 exist? Class 1, 2, and 3 are types of circuits, not wiring methods. When you look at 725.130, it is less clear that the Classes are not wiring methods, because of the permission to use low voltage cables as the wiring method, but just because you can use CL2 cable as the wiring method for a Class 2 system or circuit, does not mean that Class 2 is a wiring method.

I know what you are saying:

725.46 Class 1 Circuit Wiring Methods
Then
725.130(B) Class 2 and Class 3 Wiring Methods

Dunno, I didn't write it but if you have an understanding of Class 1 vs Class 2 and 3 it shouldn't matter. If you understand that a Class 1 circuit requires a Class 1 wiring method which is a Chapter 3 wiring method it won't be confusing. Likewise with Class 3 and 2. Art 725.133 and 725.154 gives the requirements for those circuits. And no, there is nothing to prevent someone from using a Chapter 3 wiring method for Class 3 or 2 but it isn't required except in those few instances where you have to reclassify the circuit.

-Hal