Best way to run under-cabinet lighting
#1
Member
Thread Starter
Best way to run under-cabinet lighting
I'm looking to install undercabinet lighting under the cabinets pictured below. The orange lines are wire, the red boxes are junction boxes, the black boxes are the actual lights, and the white is the switch to operate them all.
There is existing wiring from a sconce light I removed under the sink cabinet that I was hoping to utilize and avoid tampering with the other switches and outlets, particularly because the switch pictured is wired specifically for the garbage disposal, and I prefer to keep the outlet, an outlet.
The way i have it diagrammed seems like it would work, but a little messy and convoluted, is this the best approach to tackling this project from a design standpoint?
There is existing wiring from a sconce light I removed under the sink cabinet that I was hoping to utilize and avoid tampering with the other switches and outlets, particularly because the switch pictured is wired specifically for the garbage disposal, and I prefer to keep the outlet, an outlet.
The way i have it diagrammed seems like it would work, but a little messy and convoluted, is this the best approach to tackling this project from a design standpoint?

#2
The junction boxes probably aren't needed. Do the lights have junction boxes? Power should go to the switch first to comply with the 2011 code change that requires a neutral at the switch even if not needed.

#3
Member
Thread Starter
Thanks Ray,
The kit I'm looking at only requires a 24V transformer, and from there the lights are connected in rope fashion. It would be easiest to wire the transformer after the switch under the cabinet on the left, and then fish the interconnecting wire to the rest of them, but I'm going to guess that that's probably not up to code to be running that type of wire behind a wall. Should I be looking for a kit that has junction boxes at each light so i can fish BX behind the wall instead?
My biggest confusion is going from the wiring stringing the lights together, to convert to BX to run behind the wall..
Here's what I'm looking at currently, which doesn't include the transformer..
https://www.amazon.com/Lightkiwi-E75...binet+lighting
The kit I'm looking at only requires a 24V transformer, and from there the lights are connected in rope fashion. It would be easiest to wire the transformer after the switch under the cabinet on the left, and then fish the interconnecting wire to the rest of them, but I'm going to guess that that's probably not up to code to be running that type of wire behind a wall. Should I be looking for a kit that has junction boxes at each light so i can fish BX behind the wall instead?
My biggest confusion is going from the wiring stringing the lights together, to convert to BX to run behind the wall..
Here's what I'm looking at currently, which doesn't include the transformer..
https://www.amazon.com/Lightkiwi-E75...binet+lighting
Last edited by kkamin; 09-22-16 at 08:05 AM.
#4
You didn't say low voltage lights. That changes the answer. For the low voltage in wall connections you can normally use #18 thermostat cable. No junction boxes are required for low voltage cables. But Chicago is often an exception to the usual code so you need to check with the AHJ. The wiring for these types of light is usually secured to the bottom of the cabinets or run through the cabinets. The included cables should be fine for that if allowed by the AHJ.
The line voltage to the switch will require line voltage wiring as as required by you local code.
Better in my opinion to wire the switch to the line voltage power to the power supply (that way it won't be using power when the lights are off) but we don't know if the included dimmer is low voltage or line voltage. The lights you linked to include the power supply.
The line voltage to the switch will require line voltage wiring as as required by you local code.
It would be easiest to wire the transformer after the switch under the cabinet
#6
Member
Thread Starter
The switch is in fact low voltage, so I'll have to go line to the transformer, then to the switch, which complicates the wiring plan a bit
Edit: Actually I'm seeing this kit has a 4 way connector, so it will simplify things a lot for me. Thanks alot guys.
Edit: Actually I'm seeing this kit has a 4 way connector, so it will simplify things a lot for me. Thanks alot guys.
#7
Member
Thread Starter
Wiring
I'm looking at the transformer for the dimmer, listed as 20 AWG leads in, 16AWG leads out (which I believe is speaker wire?). My kitchen is wired with a 15amp circuit so it has 14 gauge where I'm looking to connect.
This then gets me to believe that my 18 gauge wire to run behind the walls from the output of the transformer, should be swapped out for 16 gauge wire instead, correct? Do I have to do anything in terms of the 14 gauge from the power source to the switch, and then the 20 gauge leads to the transformer?
Secondly, I'm looking at the diagram they've given online here, and it has a line going from the 120VAC to the switch which I'm assuming is the hot, and then one going to the transformer directly, bypassing the switch, which I assume to be neutral, is this correct?
This then gets me to believe that my 18 gauge wire to run behind the walls from the output of the transformer, should be swapped out for 16 gauge wire instead, correct? Do I have to do anything in terms of the 14 gauge from the power source to the switch, and then the 20 gauge leads to the transformer?
Secondly, I'm looking at the diagram they've given online here, and it has a line going from the 120VAC to the switch which I'm assuming is the hot, and then one going to the transformer directly, bypassing the switch, which I assume to be neutral, is this correct?

Last edited by kkamin; 09-23-16 at 09:08 AM.
#8
Member
Thread Starter
Done.
I solved all my wiring issues by finding a 24v dimmer switch. I took the line voltage straight to the transformer, then just output the 24v to the dimmer to control dimming without having to buy a dimmable transformer and spending 100 dollars for it, saved a good chunk of change on it. All is wired and working fantastic. Thanks for all the help on this project guys.

