electricalwiring
We're in the process of remodeling our kitchen and removing soffits around the perimeter of the room. I've opened up a portion of it above our cooktop and refrigerator and wanted to get some advice on how to proceed. As you can see, there are several NM cables that are on various circuits. These wires need to be routed above through the joists.
When I splice the wires, is it recommended or required to have separate junction boxes for each cable?
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.
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
Since the same switch will control the light over the sink (which you are swapping to a recessed light) and the lights over the island, this is easy.
When you add the wire for the island lights, use the junction box on the new recessed light can for the make up. This is no different then connecting multiple recessed light cans together.
Best Answer
You do not need a separate junction box for each line, nor do you need one per circuit. Unless you're strapped for space inside the box, one does just fine.
The National Electrical Code does say that the junction box has to be accessible "without removing any part of the building". So any junctions will need to be accessible through some sort of hole - normally covered by a simple faceplate. All the more reason to keep the number of boxes as small as possible.