Replacing under cabinet lighting

My house came with fluorescent under-cabinet lighting. Each light was self contained with its own switch, and was hard-wired into the electrical system. I want to replace the lights with low voltage LEDs. My question is, when I remove the existing fluorescent lights, what should I do with the source wiring? Just putting wire nuts on the ends of them and leaving them dangling (although I tuck them into a corner or something--they wouldn't actually be "dangling") doesn't sound like it is quite enough. After all, those wires will be live. I can't isolate just that circuit either, so I can't just turn that circuit breaker off. And they aren't connected to a single wall switch or anything like that. So, what should I do with those wires?

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Is there one romex cable at each light or do some lights have more than one romex (in/out)?

I would find the nearest junction point for each wire and completely remove them if you have no plan on using them. If they are wired to a central point or a junction box above the ceiling in an attic, you can try to use the romex as a pull for the LV cabling to the existing spot. Success does depend on how tight the staples are and how many there are. It also depends on the way the wires run.

I would definitely remove the wiring or minimally find the nearest junction point and isolate/cap off the wires to the light locations.

No, you can't just cap off live wires unless they are capped off in a junction box and that box must be accessible. If you disconnect the wires upstream like Gatchel says that is acceptable, then the wire can be abandoned in the wall if necessary (best to remove it though if possible). Some people tie the hot and neutrals together, cap and wrap with tape, on abandoned (NOT LIVE) wires at each end, so if someone comes across one end in the future and connects it up it will immediately blow the breaker.

If you are unsure about any of this, then hire an electrician. But you may be into opening some walls for this project. It is better to do some drywall than it is to have your house burn down and the insurance company not pay because you did something wrong or someone get electrocuted.

Unfortunately, there is only one romex going into each light. I guess they run back to one or more of the light switches in the kitchen. I am doing this project in conjunction with installing new backsplashes, so tearing up some drywall won't be so bad.

Go to Lowes. They have 'hardwire' boxes just for this. Depot didn't have them. It's a junction box with a small switch and outlet. So you can leave the switches on if already controlled by a wall switch. I can post a picture if you'd like.

@Frunple, I am not sure what you mean. Can you post a link or a picture?

You can see how it mounts under the cabinet. It has a hole in the bottom (as seen on counter pic) that will go up against the wall side for a snap-in romex clip.

MrGibbage,

I understand you want to switch to LED from the fluorescent but how are you going to power the LEDs if you cap the existing wiring? Here is what I am doing and wondering if this would work for you, which is very close to what Frunple appears to have installed. I have a switch that controls a wall outlet inside the (back of) cabinet to which I plug in a low voltage LED transformer with the low voltage side driving rope LEDs above the counter. So this gives me a wall switch that controls the under cabinet LED lights. Would this not work for you as well or am I missing something?

If this does work for you, you'll need to follow Frunple's recommendation to get some junction boxes. If you don't understand what Frunple and I are describing, I'd definitely recommend giving an electrician a call. I did electrical work many, many years ago but still call an electrician friend just because of my fear of a fire and the insurance company trying to say things weren't wired correctly.

David

If you're doing the backsplash anyways, might as well fix it how you like it. There are some options - like hard-wiring some more compact LV transformers to power the LED's, or just cap/pull the wiring.

One tip - if you have to cut any wires that you can't pull out completely, wire nut the white and black together - that way if anyone finds those wires in the future and hooks them to power, it blows the breaker instead of leaving unknown live wires - that's what the electricians I've seen always do.

LOL, DO NOT wire nut the black and white together unless you absolutely know the whole circuit you're working on!
Can't tell you how many times I've seen people extend a 20amp circuit with 14awg wire.

Frunple said:

You can see how it mounts under the cabinet. It has a hole in the bottom (as seen on counter pic) that will go up against the wall side for a snap-in romex clip.

Click to expand...

This is exactly what I want but Lowes didn't have it and I can't find it online. Anybody got any ideas?

Frunple said:

LOL, DO NOT wire nut the black and white together unless you absolutely know the whole circuit you're working on!
Can't tell you how many times I've seen people extend a 20amp circuit with 14awg wire.

Click to expand...

First cardinal rule with electrical is to first remove power from the circuit you're working on, followed by testing your meter on a known voltage source, then check the cable you're about to work on for voltage. Working on a live circuit is only if absolutely required for troubleshooting or continuity (special circumstances) of service.
 
It is very much common practice to pony the white/black/ground conductors under a single nut on an abandoned run (assuming the field cables terminate in a box) at the endpoint, then locate the feed elsewhere on the circuit.

This looks to be the same thing. 

Not really contributing.. but got a laugh from this review of the product Work2Play linked to:
 
"Attempting to connect a standard romex or BX,14 gauge electric wire is tantamount to putting 15 people in a porta-potty and asking for change. Multiple cutting, twisting, fitting of wires and connectors is a an exercise in frustration and then insuring that the screw holes for the cover plate are accessable. combines to turn a simple 5 minute connection job into a 40 minute monologue of colorful expletives all while in an awkward half bent, half twisted position working under a cabinet. Patience and determination will rule the day followed by an interval of, "boy, I'm glad that's done!!!""

lol yeah, I saw that... but it was the same product as pictured above!  I'm sure if it's a situation where the romex is attached with barely enough wire to work, it'd be a real nightmare - but if it's loose enough to pull a little out to work then push it back in the wall once you get it all wired up, it wouldn't be nearly as bad.