I Thought I Had It Figured Out

When our office manager asked me to order power supplies for a new batch of branch chandeliers and Unity spotlights, I nodded like I knew exactly what I was doing. The spec was simple: 24V, 5A, something reliable. I Googled "mean well 24v 5a power supply model," found the LRS-150-24 (rated at 150W, roughly 6.3A at 24V), and placed an order for 40 units. Easy.

The wiring diagram looked straightforward. I even printed it out to hand to our maintenance team. But three hours into installation, the phone rang. The lights were flickering, one driver had melted a connector, and the branch chandelier wouldn't dim properly. My "simple" project turned into a weekend of rework and a $600 unplanned expense.

It took me 3 years and about 150 orders to understand that a power supply wiring diagram is just the tip of the iceberg. The real question is: what kind of load are you powering, and how are you controlling it?

The Surface Problem: Everyone Blames the Wiring

The first thing people assume—and I was guilty of this too—is that the wiring diagram is wrong or incomplete. The Mean Well LRS-150-24 wiring diagram is fine. AC input L/N, DC output +V/-V, done. But it doesn't show the dimming circuit for a 0-10V dimmable LED driver, or the overload protection cutoff when you daisy-chain five spotlights. The diagram is correct, but it's only correct for a basic resistive load. Your chandelier? Not resistive.

I called our supplier and asked for a mean well dimmable led driver datasheet. They sent me the LPC-60-700 (constant current, 700mA). That's when I realized: I ordered a constant voltage supply (LRS) for a constant current application. Surface problem: wiring confusion. Deeper problem: load type mismatch.

The Deep Reasons Nobody Talks About

After spending a day digging through Mean Well's product families, I uncovered three hidden layers that most buying decisions skip:

  • Constant Voltage vs. Constant Current. Many chandelier LED modules expect constant current (e.g., 700mA or 350mA). A constant voltage supply like the LRS-150-24 will overdrive them unless you add resistors or a current-limiting circuit. The wiring diagram doesn't tell you that.
  • Dimming compatibility. My Unity spotlights had a 3-in-1 dimming input (resistor, PWM, voltage). The LRS-150-24 isn't dimmable. I should have used a Mean Well HLG series or the LPC series with dimming pins. The wiring diagram for dimming involves extra wires and a specific resistor range—something I didn't know existed until I read the application note (note to self: always read the application note).
  • Thermal derating. The LRS-150-24 is rated for 150W at 25°C, but our junction box sits near a heat register. At 50°C, the usable power drops to ~120W. The wiring diagram doesn't show a temperature curve. My chandelier was pulling 130W peak. That's why the connector melted. (Should mention: I later learned Mean Well publishes derating curves in the user manual—I just hadn't read past the wiring section.)

The question isn't "which mean well power supply wiring diagram do I follow?" The real question is: what problem am I actually solving?

The Cost of Ignoring the Details

Let me paint the financial picture. My 40-unit order cost about $480. Add the dimmer modules I hastily bought: $120. Then the weekend of my time (I'm salary, but I could have been doing more productive work). Plus the replacement LPC-60-700 drivers: $340. Total: $940 for a project that should have cost ~$600. That's a 57% cost overrun because I didn't go two layers deeper.

But the hidden cost was worse: my internal client—the operations VP—lost confidence. When I presented the monitor light bar vs desk lamp evaluation for the new open-office layout, she asked someone else to handle the procurement. That stung. I knew I should have verified the load type before ordering, but thought "what are the odds?" Well, the odds caught up with me when I had to explain the flickering branch chandelier to the CEO during a walkthrough.

In 2024, I did a vendor consolidation project for 400 employees across three locations. The lesson from the chandelier disaster saved us $2,400 in potential rework—because I now check three things before any order: load type, dimming requirements, and thermal environment. In that order.

What I Recommend Now—and What I Don't

If you're picking a Mean Well power supply for a branch chandelier, unity spotlight, or even a monitor light bar setup, here's my honest advice based on the school of hard knocks:

  • For constant voltage LED strips or arrays (like monitor light bars), the LRS series works great—provided you're not dimming and your ambient temperature stays under 40°C. The wiring diagram is exactly what you expect: AC in, DC out.
  • For constant current modules (many chandeliers, spotlights), go with the LPC series (e.g., LPC-60-700). It's designed for LED lighting with proper current regulation. The dimming version adds two extra wires for 3-in-1 control—check the application note for resistor range values (typically 100kΩ pot).
  • For DIN rail installations, the HDR series (e.g., HDR-60-24) gives you a smaller footprint and easy mounting. But note: HDR models have a lower inrush current rating; if you're powering multiple spotlights that have large input capacitors, you might need a soft-start module.

I recommend the LPC-60-700 for most dimmable chandelier applications—it covers about 80% of cases. But if you're running 15+ spotlights on one supply, you're in the other 20%: look at the HLG series with active PFC and full dimming compatibility. No one-size-fits-all. The wiring diagram will look different for each, and that's okay.

Oh, and one last thing: Mean Well publishes detailed wiring diagrams and application notes on their site (meanwell.com). I should add that the dimming resistor range (100kΩ typical) is explicitly listed in the datasheet—not in the diagram itself. That was my biggest oversight. Now I always open the full PDF, not just the one-page wiring sheet.

If you've got a project coming up, spend 20 minutes upfront on the specs. Trust me, it saves a weekend.