Undercabinet lighting

[reader4]

OK, I'm a little confused about how best to install undercabinet lighting. I have seen posts on Q&A boards about how a piece of Romex running through the wall immediately to a switch is not allowed by NEC code... but then I see this:

Installing Undercabinet Lighting | Kitchen Lighting | Kitchens | Planning and Ideas | This Old House - Introduction

which makes perfect sense to me and was how I wanted to do it in the first place (perhaps with an external wire tray for asthetics as well). So, what does code (most codes) really say about this?

The only difference for me is that I have 4 xenon pucks, rather than a fixture with a box. I imagine I would need a box to hold the connection between the 2-wire "puck-line" and the Romex. How to handle the ground? Any chance I can just send the 2-wire "puck-line" into the wall to the switch (I doubt it, but it's worth asking)?

Thanks!

[HayZee518]

From what I read you have the option of wiring longer than 10 feet from the fixtures or within ten feet. I looked at that "this old house" wiring and this makes sense too! The pucks are 12 volt AC, two wire so don't worry about a ground wire - there won't be any. There is however a 120 volt to 12 volt step down transformer that you have to contend with. The only way I can see this install is to compromise part of your cabinet space to install a junction box [for 120 volt splices] for the input off a dimmer and the transformer primary. Not having seen the transformer I can only assume the secondary is a pair of screws - like a bell transformer to which the lamp load is connected. Run your load off the dimmer in romex up through the back of the cabinet to a 4 inch junction box [side knockout] Mount the transformer in another side knockout and make up the primary inside the box. The bare ground would go to the metal of the transformer shell and the metal box. This keeps the ground bonding rule in check. The low voltage secondary would go back down through the cabinet bottom in a corner and around the front where I assume the pucks are located and wired in parallel from one fixture to another.

[596]

The picture you show is the installation of a new outlet, to which the lights would simply be plugged in with a proper cord and plug. This is perfectly acceptable, but not necessarily pretty.

The only way to connect directly to the light strips would be with flex like MC conduit, coming from an approved box. probaly in the ceiling or in the wall behind the cabinet. This could come through the cabinet, through the floor of the cabinet box to the light strip. It would all be concealed from view, but would be visible when the cabinet foor was open.

I have also seen these run very discretely just on the underside of the cabinet. Takes a little more planning to get everything just in the right spot

[reader4]

There is however a 120 volt to 12 volt step down transformer that you have to contend with.

My lighting actually uses 120V xenon bulbs. The kit provides a direct outlet plug-in, but I would like to hide the wiring. So, I intend to either connect the wire leads from the bulb directly to the switch (which I doubt is allowed - it would be too easy) or connect the wire leads to the Romex extending beyond the wall. The lights are about 8-10" away from the wall. I figure I will need a box to cover the bulb wire-Romex connection, but after looking at the TOH figures again (see "Overview"), it looks like they installed a wood cover over the bare Romex. Never heard of or seen this. Thoughts?

[HayZee518]

the electrical box manufacturer makes a junction box that is smaller than a handy box I believe it is about 1 1/8" square by about three inches long. you can come into one end with your romex and exit the other end with SO cord - 16-14 gauge. Run the cord up in back of front lip of the cabinet in the corner to each puck lamp. go to a home center and get a piece of external 90 degree corner moulding also some #6 or #5 X 1 1/4 flat head screws. you may need to trim off one leg of the moulding so it lies closer to the depth of your cabinet overhang. drill a clearance hole every few inches - 6 or 8 in the moulding and countersink the hole. place the moulding to cover the cord and screw the moulding to the cabinet bottom.