low voltage splice

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rich000

Senior Member
we are finishing a basement and drywalling the ceiling.

the doorbell transformer is in the ceiling and needs to be moved (for future replacement etc.).

can i splice the low voltage 18AWG wires and leave them in the ceiling or do they need to be accessible?

Thank you.
 

aphares

Member
Location
Indiana
Re: low voltage splice

Accessible from in the room ? No.

Accessible like the door bell, for when the connection needs attention ? Yes.

If the walls are open and both ends of the cable can be accessed then replace it. 18/2 cable is cheaper then putting a hole in the ceiling when you need to get to it.
 

rich000

Senior Member
Re: low voltage splice

I am not sure I understand.

The 18/2 wires run from the bell switch and the chime to the transformer in the basement.

I do not have enough slack to move the transformer to the utility area of the basement (that area will not be finished and will be accessible).

My plan is to move the transformer to the accessible area. I would splice the 18/2 wires at the old location and run them to the transformer (I will power the transformer from another circuit in the utility room).

Can I just wirenut and heatshrink the 18/2 wires and leave them in the drywall?

I think the doorbell is a class 2 circuit. Correct?
 

tom baker

First Chief Moderator
Staff member
Re: low voltage splice

No box is needed for your splice and it can be buried. The transformer needs to be accessible.
Repulling the 18-2 as mentioned would save possible trouble later, but its not required.
 

aphares

Member
Location
Indiana
Re: low voltage splice

Establishing what Article 725 is about and what it is not about. Common misconception about Article 725 is that it allows CL2 or similar "thermostat wire" or "bell wire" to be used on "low voltage" circuits.
The common bell cable that is used in residential settings and installed for door bells, is not listed per Article 725 as being classified for class 1, 2, or 3. circuits. (unless your cable is listed per Article 725) Other Articles would then Apply in this case.

90.3 This Code is divided into the introduction and nine chapters, as shown in Figure 90.3. Chapters 1, 2, 3, and 4 apply generally; Chapters 5, 6, and 7 apply to special occupancies, special equipment, or other special conditions. These latter chapters supplement or modify the general rules. Chapters 1 through 4 apply except as amended by Chapters 5, 6, and 7 for the particular conditions.
(chapter 1-4 Adds to Article 720)
720.2 Other Articles.
Installations operating at less than 50 volts, direct current or alternating current as covered in Articles 411, 551, 650, 669, 690, 725, and 760 shall not be required to comply with this article.

300.2 Limitations.
(A) Voltage. Wiring methods specified in Chapter 3 shall be used for 600 volts, nominal, or less where not specifically limited in some section of Chapter 3. They shall be permitted for over 600 volts, nominal, where specifically permitted elsewhere in this Code.

300.15 Where the wiring method is conduit, tubing, Type AC cable, Type MC cable, Type MI cable, nonmetallic-sheathed cable, or other cables, a box or conduit body complying with Article 314 shall be installed at each conductor splice point, outlet point, switch point, junction point, termination point, or pull point.

314.29 Boxes and Conduit Bodies to Be Accessible.
Boxes and conduit bodies shall be installed so that the wiring contained in them can be rendered accessible without removing any part of the building or, in underground circuits, without excavating sidewalks, paving, earth, or other substance that is to be used to establish the finished grade.

Not only a box would be required, but also have to be accessible per code.

Hope this helps.

[ March 01, 2003, 08:54 AM: Message edited by: aphares ]
 

don_resqcapt19

Moderator
Staff member
Location
Illinois
Occupation
retired electrician
Re: low voltage splice

aphares,
I checked online with 2 manufactures of thermostat wire and both are listed as CL2 cables. This is the common multiconductor #18 solid. Most door bell transfomers are listed as NEC class 2 power supplies, so Article 725 does apply to this installation. I find no modification to 300.15 and 314.29 in Article 725 so these sections do apply and an accessible box is required.
Don
 

aphares

Member
Location
Indiana
Re: low voltage splice

Thanks Don. I agree most door bells are listed as CL2, But I guess it is a bad assumption on both of our parts to think the cable is listed as CL2, or not. Since neither one of us has not seen it. Most of the larger manufactures today are producing CL2 cables over the lower grade bell wire, But most stores unknown of the code still sell non-listed CL2 cable, For this type of installation. And you know as well as me. The cheapest Cable on the market ends up in the customers house. But we both come up with the same conclusion.
 

fishin' electrician

Senior Member
Location
Connecticut
Re: low voltage splice

I have to disagree that a box is required.

('99) 725-3. Only those sections of Article 300 referenced in this article shall apply to Class 1,2 & 3 circuits.

I find no reference to 300-15 for class 2 circuits.

If a box was required, wouldn't the transformer itself then have to be installed in an enclosure? And how would these have gotten a UL listing,
cady?
 

aphares

Member
Location
Indiana
Re: low voltage splice

I read that, And re-read it about 50 times. The way I am picking it up is, Chapter 1-4 apply except for (A-F) Special conditions. And for those special conditions not all of chapter 1-4 apply except for the referenced Articles per 725.3.

The reason I am leaning this way is other references to chapters 1-4 in Article 725.

725.1 fpn
725.1 "Commentary" paragraph 6

Now also reading it as a whole "Circuits and equipment shall comply with the articles or sections listed in 725.3(A) through (F)."(nec)"

If all of Article 725 was to apply only to 725 then the above statement would say "725" not 725.3 (A-F) I am saying these are special rules, but if it is not listed in (A-F) then chapter
1-4 apply in there entirety.

Am I off base ?????
 

don_resqcapt19

Moderator
Staff member
Location
Illinois
Occupation
retired electrician
Re: low voltage splice

fishin,
I stand corrected. I didn't look at 725.3. It appears that the only sections of Article 300 that you must comply with for 725 installations are those sections specifically called out in 725. The only low voltage Chapter 7 Article that requires compliance with 300.15 is Article 760.
Don
 

rich000

Senior Member
Re: low voltage splice

Thank you for the help. I am also awaiting an answer from the AHJ. I will let you know the results. Thanks again.
 

jmc

Member
Location
Massachusetts
Re: low voltage splice

The Article governing this installation is very clear in Section 725.3 where it states "Only those sections of Article 300 referenced in this article shall apply to Class 1, Class 2, and Class 3 circuits". Section 300.15 DOES NOT APPLY!
John M. Caloggero.
 
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