Who This Is For (And When to Use This Checklist)
I review roughly 200 unique lighting and wiring items a year — from basic switches to multi-room Zigbee lighting control panels. In Q1 2024, I rejected 12% of first-delivery electrical samples due to spec mismatches or installation corner-cutting. That stat keeps me up at night, because by then the customer has already signed off.
This checklist is for electrical contractors, facility managers, and B2B specifiers who are putting in a Legrand switch — specifically the radiant or Adorne family — and then figuring out how to power a run of under-cabinet LED strip lights off the same system. If you’ve already googled “how do you power LED strip lights” and gotten 80 different answers, this is the actionable path I’ve validated.
It’s not a full electrical guide. It’s a 6-step checklist that catches the things I see go wrong in the field.
Step 1: Verify the Load Type on Your Legrand Switch
This is the step most people rush past. You bought a “legrand lighting switch” — great. But which one?
The radiant line has a standard single-pole, a 3-way, and a dimmer rated for LED loads. If you’re trying to control a smart bulb (which has its own driver), a standard dimmer can cause flicker or worse, buzz. If you’re running a low-voltage LED strip (12V or 24V), you need a switch that can handle the driver’s inrush current, which isn’t the same as the run rating.
I’ve seen a contractor install a radiant dimmer for a run of strip lights that pulled 36W total. On paper, 36W is fine for a 150W-rated dimmer. But the driver’s inrush was 1.2A for 20ms. The dimmer tripped on that twice before they swapped to the occupancy-sensor version, which handles inductive loads better. It cost them a site visit and a part swap.
Check: Confirm the Legrand switch spec sheet includes “LED compatible” or “Low-voltage driver rated.” If it says “incandescent only,” it’s not your part.
Step 2: Choose the Right Power Source for the LED Strip
The question “how do you power LED strip lights” usually gets answered with “plug it into a wall outlet.” That’s fine for a bookshelf. For under-cabinet lighting in a commercial kitchen or a spec office? Not fine.
You have three real options:
- Direct hardwired driver (recommended for permanent installs): A Class 2 driver wired to a junction box. Clean, no dangling plugs, passes inspection.
- Plug-in driver + switched outlet: Works if the cabinet has an accessible outlet. Use a Legrand switch to control the outlet, not the strip directly.
- Smart bulb / Zigbee socket adapter: If the customer wants app control, a Legrand Zigbee socket plugged into an outlet can switch the strip’s driver. You lose hardwired stability but gain smart-home integration.
My go-to is the hardwired driver. On a $18,000 under-cabinet lighting project I reviewed last year, the contractor spec’d plug-in adapters for 28 fixtures. By year two, 4 adapters had failed from heat cycling. Hardwired drivers were a $14 upcharge per fixture. The client paid it on the redo.
Step 3: Match the Driver Output to Your Strip Voltage
You’d be surprised how often this goes wrong. Your LED strip says “24V DC.” Your driver outputs “12V DC.” You hook it up, and the strip glows at like 30% brightness — or not at all. The fix is a $40 driver swap and a schedule delay.
Legrand doesn’t sell the driver, but they make an Under Cabinet Lighting Kit that includes a pre-matched driver and strip. If you’re mixing and matching, you need to be precise.
Check: Read the strip’s cut-sheet. Confirm voltage (12V or 24V). Confirm max run length (most drivers have a 16-foot limit before voltage drop affects brightness). If you’re running longer than 16 feet, you need a dual-feed or a higher-gauge wire run.
Step 4: Wire the Switch to the Driver (Not the Strip)
This is the wiring step. The switch’s load wire goes to the driver’s input (line side), not the strip itself. The strip connects to the driver’s low-voltage output. It sounds obvious, but I’ve rejected three batches in the last year where the field wiring bypassed the driver, feeding 120VAC direct to the strip. That blows the strip LEDs instantly.
Here’s a typical sequence:
- Power off at breaker.
- Connect Legrand switch line/hot to the junction box line.
- Connect switch load to the driver’s black (line) wire.
- Connect driver’s white (neutral) to box neutral.
- Connect driver’s low-voltage DC output (+ and -) to the strip’s pads.
- Ground everything.
That’s it. If you have a Legrand occupancy sensor or Zigbee dimmer switch, the wiring is the same — just make sure the switch’s load rating covers the driver’s full draw. The driver’s label will list “input current.” Multiply by 1.25 for safety margin. If it’s 0.5A, your switch needs to handle at least 0.625A. Most Legrand switches handle 5A or more, so you’re usually fine.
Step 5: Test the System (And Don’t Skip the Dimmer)
I have mixed feelings about dimmers on LED strips. On one hand, everyone wants the “sunset mode” effect. On the other, most dimmable drivers need a specific trailing-edge or 0-10V dimmer — and a standard residential dimmer won’t work without a noticeable flicker at low levels.
Legrand’s Adorne dimmer is compatible with many low-voltage drivers, but you need to check the driver’s compatibility list. I went back and forth between a Lutron and Legrand dimmer for a kitchen project. On paper, the specs were identical. My gut said Legrand for consistency across the brand. It worked flawlessly on the first try — but only because the driver’s datasheet explicitly said “compatible with Legrand Adorne.” If it doesn’t say that, it doesn’t mean it’s not compatible — but I’d order a sample first. That $22 test saved me from a $14,000 batch rejection later.
Check: Dim the strip to 10%. If you see flicker, you have an incompatible pair. Swap the driver or the dimmer before going live.
Step 6: Secure the Connections and Label the Circuit
I know this sounds like “common sense,” but it’s the #1 thing I flag in site audits. Loose wire nuts on the switch-to-driver connection cause arcing. No labeling on the driver means the next electrician will think the driver is the strip, cut power to the wrong thing, and get zapped.
After the install:
- Use Wago lever nuts or appropriate wire nuts. Crimp the connection, then tug test each one.
- Label the driver: “LED strip driver — switch at [location].”
- Label the breaker: “Kitchen under-cabinet lights.”
I inspected a facility’s lighting panel where the driver was in a junction box above a drop ceiling. No label. The maintenance guy found it the hard way when he replaced a switch and hit the driver’s line side with a screwdriver. That defect didn’t just cost a repair — it cost us an OSHA visit. Now I require labeling in every spec.
Common Errors I See (And How to Avoid Them)
- Overloading the switch’s neutral wire: If you’re using a smart switch (Legrand’s IoT Onboard), it needs a neutral wire. Some old junction boxes don’t have one. If you skip that check, the switch won’t power on. I’ve seen this on 10% of retrofit installs this year.
- Mixing dimmer types: I already covered this, but I’ll say it again: a phase-cut dimmer (forward or trailing) is not the same as 0-10V. If your driver expects 0-10V and you give it a phase-cut dimmer, you get either full-brightness or a 10-second flicker until the driver fails.
- Forgetting the Zigbee socket adapter: If you’re connecting a Legrand Zigbee socket to control the strip, plug the socket into the switched outlet, then plug the driver into the socket. Don’t wire the Zigbee socket inline — it’s a plug-in device only. Every electrician I know has tried to hardwire it once. We’ve all learned the hard way.
Prices as of January 2025. Verify current rates and compatibility lists at legrand.us. Regulatory information is for general guidance — consult NEC 2023 for your jurisdiction.
That’s the checklist. It’s not flashy. But follow it, and you won’t have to do a re-wire after the drywall is up.