That First Look Was Deceiving
It was September 2022. I was standing in the lobby of a 1920s office building that had just been sold to a tech company. The client wanted to keep the grand staircase—marble steps, wrought iron railings, the whole deal. But they wanted modern lighting. “Keep the antique chandelier, but make it bright,” they said. And then they added the kicker: “And we want LED strip lights under the stair treads. Can you do that?”
Sure, I said. No problem.
I was six years into handling electrical and lighting orders for commercial spaces. I'd spec'd Eaton lighting controls for warehouses, Eaton surge protectors for server rooms, even a whole-house Eaton panel for a VP's home renovation. I knew the products. But I was about to learn a hard lesson about power supply specs and why assumptions are dangerous.
The Three-Way Split
The project had three distinct lighting zones. First, the antique chandelier—a six-arm brass fixture that had probably been there since the building opened. We were going to retrofit it with new LED candle bulbs (warm dimmable, of course). Second, the staircase accent: LED strip lights installed under each tread. Third, a pair of modern sconces for the wall niches.
I ordered an Eaton lighting contactor for the main control—neat, clean, could handle the switching. For the chandelier, I spec'd an Eaton power supply (the standard 24V DC, 60W). Simple.
Here's where it got messy. The LED strip lights I picked came from a specialty supplier. They were 'cuttable every 100mm,' and the client specifically asked (I remember this quote clearly), “Can you cut LED strip lights and they still work?” I said yes, of course you can. You cut them at the marked line, solder or connect the terminals, and they work. (Ugh, that confidence still makes me cringe.)
The stairs required three strips, each exactly 1.2 meters long. I calculated: 3.6 meters total, each strip drawing 10W per meter. That's 36W. I picked an Eaton 24V power supply rated for 60W—plenty of headroom, right?
The Moment I Knew I Messed Up
The order arrived. The chandelier retrofit went fine—the warm LEDs looked beautiful against the antique brass (finally!). The sconces were fine. Then the electrician started installing the stair strips.
He cut the first strip. Connected it. Tested it. It lit up. Then he cut the second strip. And the third. Connected them in parallel to the Eaton power supply. Flicked the switch.
The first 40 cm of each strip was bright. Then the light faded, strip by strip, until the last 20 cm of each length was a dim, yellowish glow.
“Check the connections,” I said. He did. “Check the power supply,” he said. I did. The Eaton unit was outputting 24.1V. Fine. But the current was maxed out at 2.5A—the limit of that 60W supply.
I stared at the datasheet on my phone. The LED strips were 14.4W per meter, not 10W. I'd misread the spec. 3.6 meters × 14.4W = 51.84W. Still within the 60W capacity. Barely. But the voltage drop over 1.2 meters meant the last LEDs didn't get enough juice to stay bright.
I still kick myself for that moment. If I'd used a higher-voltage supply (like a 48V system) or specified a larger 24V unit with proper current distribution, I wouldn't have had to replace everything. But I didn't.
The fix: rip out all three strips, order new ones with thicker conductors, and pair them with a 24V Eaton power supply rated for 100W. And re-install. Total cost? $380 in new strips, $95 for the new power supply, $375 in electrician labor. The original $450 order? Straight to the trash.
The Real Lesson Wasn't About Cutting Strips
Look, I know what you're thinking: “So you bought the wrong LED strips. Big deal.” But here's what I learned from this mess, and it's stuck with me through every project since.
Total cost of ownership is real. The 'cheaper' 60W Eaton power supply—which is a great unit, by the way, I've used dozens since—cost me more in the long run because I didn't spec it correctly. The 100W version was $45 more. The redo cost me $850. I don't have hard data on this industry-wide, but based on my five years of orders, I'd estimate about 60% of 'budget overruns' come from the second round of purchases, not the first.
Second lesson: Cuttable LED strips are great—until they aren't. The 'can you cut LED strip lights' question is easy to answer (yes), but the follow-up question should be: “What happens to the voltage drop when you cut them to non-standard lengths?”
And the biggest lesson? Never trust your memory on specs. I'd used those strips before on a different project, but that one had a 48V supply. I assumed the 24V version would behave the same. It didn't. Now I keep a printed reference sheet in my bag (yes, physical paper) with the specs for every product I regularly order: Eaton power supplies, lighting contactors, strip types, everything.
How This Changed My Process
After that September 2022 fiasco, I created a pre-order checklist for anything involving LED strips and power supplies. It's saved us from at least 15 similar mistakes in the past 18 months (I've been tracking). The checklist asks three things:
- What is the exact wattage per meter of the strip (confirmed from the datasheet, not memory)?
- What is the total length of strip being powered from a single supply?
- Is the power supply rated for at least 20% more than the calculated total (to handle voltage drop)?
Honestly, I'm not sure why I didn't think of this before. My best guess is that I'd gotten complacent—Eaton products are so reliable that I stopped double-checking the basics. The power supply didn't fail. The strips didn't fail. My assumptions failed.
I still feel a little embarrassed when I walk into that building. The chandelier looks gorgeous (finally!). The stair strips look great now, too. But I know that under the marble treads, there's a $850 lesson in power supply planning—and a reminder that value isn't the same as price. The cheapest option (or the easiest one) is rarely the most cost-effective.
If you're working on a similar project—mixing antique fixtures with modern LEDs, or just trying to figure out the right Eaton power supply for your setup—save yourself the headache. Start with the total wattage, add 20%, and go from there. And if you're not sure? Ask. I wish I had.