I realize that local codes can vary, but I'm wondering if this is ever
allowed. I have an application where I need to power 2 alarm
transformers. They are 'bricks' that convert to 12 volts and have a
screw that permanently attaches them to an outlet (a long screw that
replace the short one used to hold the outlet cover on). 12 volts comes
out of them. There would be no 120v cords above the drop ceiling, only
low voltage. So in this scenario would I be so in violation of the NEC
if I put an outlet above the drop ceiling? I won't bother chasing down
the local code if this is an outrageous idea.
If you install the outlet in a box w/ cover, etc., and all it takes is
removing a tile from the ceiling to gain access, I'm perfectly
comfortable w/ that.
I've seen it in many commercial places, for example I was standing at a
service counter in one of the big chains just the other morning waiting
to meet someone and observed they had their checkouts powered by plugins
to the ceiling outlet boxes via a power cord to outlets (110V) on the
ceiling at about 30-ft which powered another power mast for four-six
registers/mast. Thought that somewhat interesting rather than being
permanently wired. There were portions of that ceiling that were open,
others that did have dropped ceilings in certain other departments but
the local registers were hooked up via the same mast arrangement I noticed.
Just an observation and imo, I don't know chapter/verse of NEC for the
situation but I don't think that the loose ceiling tiles count for
To be honest, sometimes I am surprised by the things that aren't
allowed. I don't always see the big picture when I'm focused on a
particular application like this. I have seen outlets above drop
ceilings in businesses, powering their network routers & switches, but I
never stopped to think whether or not it was in compliance with the code.
I'd be very careful to conceal what you're doing. If it does violate
the codes, you're in big trouble. You do know that the Bush
administration passed a bill allowing building inspectors to cut the
testicles off homeowners who violate federal and/or local codes.
Yeah, I know, it sounded a bit paranoid. But I don't keep up with every
code change and I figured it wouldn't hurt to ask. I don't fear the
government half as much as the insurance company! I just want my stuff
in compliance with the code!
Long ago I was at a party and met an electrical inspector. I didn't
think he would want to talk about business but he surprised me. I had a
bunch of questions about keeping in compliance and he answered every one
of them. What surprised me the most was the old work/new work stuff he
taught me (don't have to worry about stapling to the studs when fishing
a new wire in an existing wall, etc.). I was wanting to get rid of a
bunch of old knob and tube and was hung up on a lot of little nits
because most of what I had learned had been in new construction.
Anyway, the thing I never forgot was him telling me that he never, ever
wanted to get in the way of someone trying to improve their service to
modern standards. He was not there to discourage improvements, only to
ensure that the work was safe and of reasonable quality.
The space above a drop ceiling can be part of the air return for the
HVAC system and therefore need plenum cable and possibly have other
special requirements. That is more common in commercial environments
than in a home, but it makes sense that he asked. I just don't know
I don't know for sure, but I think the deal is that you can't have outlets
and junction boxes that are not accessible -- such as in a wall or ceiling
behind sheetrock, etc. But, if it is accessible -- meaning there is an
access panel that can be easily opened to get to the outlet or junction box,
or in this case, a dropped ceiling panel that can be opened or moved -- it
So, I think that yes, you can do what you want to do.
T. McQuinn wrote:
Nothing in the NEC prohibits the installation of a receptacle above a
drop ceiling. Section 400.8(5) of the NEC prohibits the use of
flexible cords ". . . located above suspended or dropped ceilings".
However, my understanding is that low voltage flexible cords are
exempted from this (although I have not read the appropriate Chapter 7
sections). So I believe it is OK to permanently install a wall wart
in a receptacle above a drop ceiling.
But iirc (and Wayne's cite seems to confirm) it's cords _above_ the
ceiling that are prohibited. I don't believe that prohibits coming from
above to below -- if it did, it would mean Walmart and many other
commercial facilities are non-compliant for the above examples.
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