What is the proper way to install a junction box above a dropped ceiling?

Question

I'm doing some remodeling in my basement and part of that work involves moving a switch. When I was tracing the wires for the switch I found this above my dropped ceiling:

Now, I'm no electrician, but this does not look up to code to me. Further investigation revealed this in another area of the ceiling:

I'm unsure if these junction boxes are installed to code, the one with all the wires hanging out of it looked particularly suspicious to me.

Now, for the first picture, my idea was to install a junction box in between the joists just to the right of the picture (hot wire is coming in in under the joist to the right, the switch & an outlet are toward the camera, and the load the switch controls is off to the left). I'll probably end up re-running a couple runs of wire, but that's not a problem as everything is accessible right now.

My primary question is, does NEC allow for junction boxes installed above a dropped ceiling?

Are the boxes in the second image installed correctly, and if not what is the correct way to install a junction box in this space?

Answer 1

There is no problem with installing junction boxes above a suspended ceiling, as long as the box is less than 100 in.³ and securely fastened. National Electrical Code has this to say...

National Electrical Code 2014

Chapter 3 Wiring Methods and Materials

Article 314 Outlet, Device, Pull, and Junction Boxes; Conduit Bodies; Fittings; and Handhole Enclosures

II. Installation

314.23 Supports. Enclosures within the scope of this article shall be supported in accordance with one or more of the provisions in 314.23(A) through (H).

(D) Suspended Ceilings. An enclosure mounted to structural or supporting elements of a suspended ceiling shall be not more than 1650 cm3 (100 in.3) in size and shall be securely fastened in place in accordance with either (D)(1) or (D)(2).

(1) Framing Members. An enclosure shall be fastened to the framing members by mechanical means such as bolts, screws, or rivets, or by the use of clips or other securing means identified for use with the type of ceiling framing member(s) and enclosure(s) employed. The framing members shall be adequately supported and securely fastened to each other and to the building structure.

(2) Support Wires. The installation shall comply with the provisions of 300.11(A). The enclosure shall be secured, using methods identified for the purpose, to ceiling support wire(s), including any additional support wire(s) installed for that purpose. Support wire(s) used for enclosure support shall be fastened at each end so as to be taut within the ceiling cavity.

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Code Violations

In the first image, the wires being spliced together like that violates NEC 300.15.

300.15 Boxes, Conduit Bodies, or Fittings Where Required. ... 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 shall be installed at each conductor splice point, outlet point, switch point, junction point, termination point, or pull point...

I've also noted some violations in the second image.

^{Click for larger view}

Answer 2

You are on the right track. Junction boxes, with blank covers are allowed above a suspended ceiling as it is not considered a closed space. The wires that are loose and wirenuted need to be put in a j-box. Also, clamps need to be used at each wire going into a j-box. Some boxes have clamps pre-installed, if not, you need to use a RX connector in the knockout. Hard to tell from your pics if they are installed. Also, an open hole in the j-box with no wire is not acceptable. Solid metal covers need to be installed on the boxes.

Answer 3

I think even with junction boxes image is still illegal as there should be an insolated bearrier between the 2 junction boxes