On Mon, 10 Apr 2017 00:20:40 -0400, wrote:

On Sun, 09 Apr 2017 19:42:07 -0400, wrote:

On Sun, 09 Apr 2017 11:30:18 -0400, wrote:

On Sun, 09 Apr 2017 01:20:14 -0400, wrote:

Insurance companies like to see that all wiring is/was up to code if they are to pay a claim for any future damages.
No code for class 1 or class 2 12 volt wiring.

Perhaps you should take a peek at article 725.
BTW "class 1" can also include 120v wiring (up to 600v) and from a
life safety standpoint, there is no significant difference. That is
why Class 1 circuits use chapter 3 wiring methods.
Don't confuse Class 1 with Class 2 or Class 3 but all are covered by
the code.
.

OK - I was wrong.
Notice I specified "12 volt" wiring
However I may have misunderstood the original situation. People are
talking about attic and wires in the wall. The way "I" understood the
question the OP had a device that mounted on the wall very close to
the ceiling on either the main floor of a 2 storie, or the basement of
either a single or multi story building, with an electrical outlet at
the normal low-level postion directly above the location of the
device, where the wall-wart could be connected. The question as I
understood it was whether he could pass the power cable from the wall
wart down through the upper floor and the ceiling below..

Now - ASSUMING this is a single family residence and the
ceiling/floor is not required to be a total fire stop, there is no
building code violation involved in drilling a hole in the ceiling or
the floor. Also, I'm assuming, as usually is the case, the cavity
between the upper floor and lower ceiling is not stuffed with
insulation, which means any wiring in that cavity does not need to be
oversized or de-rated for elevated temperatures.

Also I'm ASSUMING the power supply is a pluf connected UL or CSA
approved pwer supply that is current limited and listed as an
ultra-low voltage class 1 or class 2 current limited device. with
integrated wiring..

If all these assumptions are true, I don't believe there is any code
that SPECIFICALLY prevents the OP from drilling a hole in the floor
above and in the ceiling below and dropping the cord down to the wall
mounted device. This does not "hide" the wires, but it greatly reduces
the amount of exposed cable and removes the "wall wart" from view in
the primary living space..

This is how I interpreted the original question.
Running a piece of flexible tubing between the floors to guide the
wire and prevent accidental damage might possibly be adviseable, but
not required..

In my understanding the power supply MUST be accessible and can not
be "permanently installed"

Low voltage "lighting" is addressed in the code and is a different
story UNLESS it is a "light tape" or "rope" type lighting device,
which at least in Canadian Electrica Code, is exempt.

Installing in an unfinished attic space might cross the line due to
"accessibility" and insulation issues.


725.154
(B) Riser. Cables installed in risers shall be as described in any of
(B)(1), (B)(2), or (B)(3):
(1) Cables installed in vertical runs and penetrating more than
one floor, or cables installed in vertical runs in a shaft, shall be
Type CL2R or CL3R. Floor penetrations requiring Type CL2R or CL3R
shall contain only cables suitable for riser or plenum use. Listed
riser signaling raceways and listed plenum signaling raceways shall be
permitted to be installed in vertical riser runs in a shaft from floor
to floor. Only Type CL2R, CL3R, CL2P, or CL3P cables shall be
permitted to be installed in these raceways.
(2) Other cables as covered in

Also note:

and other listed
wiring methods as covered in Chapter 3 shall be installed in metal
raceways, or located in a fireproof shaft having firestops at each
floor.
(3) Type CL2, CL3, CL2X, and CL3X cables shall be permitted in
one- and two-family dwellings. Listed general-purpose signaling
raceways shall be permitted for use with Type CL2, CL3, CL2X, and CL3X
cables.
FPN: See 300.21 for firestop requirements for floor penetrations.


OK
(1) Cables installed in vertical runs and penetrating more than
one floor, or cables installed in vertical runs in a shaft, shall be
Type CL2R or CL3R

Does not apply - only going through one floor, therefo

Floor penetrations requiring Type CL2R or CL3R
shall contain only cables suitable for riser or plenum use. Listed
riser signaling raceways and listed plenum signaling raceways shall be
permitted to be installed in vertical riser runs in a shaft from floor
to floor. Only Type CL2R, CL3R, CL2P, or CL3P cables shall be
permitted to be installed in these raceways.

Also does not apply.


The installation requirements for the low-voltage wiring of
information technology equipment (electronic data processing and
computer equipment) located within the confines of a room that is
constructed according to the requirements of NFPA 75, Standard for the
Protection of Information Technology Equipment, are not covered by
Article 725. Low-voltage wiring within these specially constructed
rooms is covered in Article 645.

Also, if listed computer equipment is interconnected and all the
interconnected equipment is in close proximity, the wiring is
considered an integral part of the equipment and therefore not subject
to the requirements of Article 725. If the wiring leaves the group of
equipment to connect to other devices in the same room or elsewhere in
the building, the wiring is considered ‘‘wiring within buildings’’ and
is subject to the requirements of Article 725.


Note the first sentance of the second paragraph.If the wiring is "an
integral part of the equipment" it is " therefore not subject to the
requirements of Article 725"

I still maintain the NEC does not address the situation as described
above.