How to Connect Light Fixture Wires: A 7-Step Checklist for Facilities Buyers

I'm not an electrician. I'm the office administrator who handles facilities purchasing for a 250-person company — which means I place the order, approve the invoice, and get the call when half the parking lot lights are dark. Over the last four years I've learned that most "wiring problems" aren't wiring problems. They're spec problems that got baked in at the order stage.

This is my version of a "how to connect light fixture wires" checklist, but from the buyer's side of the table — which is honestly where most of these problems start. It's seven steps. It doesn't replace a licensed electrician, and if you're doing the actual connection, get a qualified person to do it. But if you're the buyer in the middle of the process, these are the checks that keep you off the phone with your VP explaining why the loading dock is dark again.

Who this checklist is for

Facilities coordinators, office managers, and procurement staff who order lighting — from a single pendant light over a conference table to 40 bega bollard lights around a perimeter path — and need to be sure the fixtures and connections will actually work with what's already on site. If you're a licensed electrician, some of this will be obvious. Skip to step 4 — that's the one most people miss.

Step 1: Confirm voltage and control type before you order anything

Most commercial interiors in the US run 120V or 277V. Exterior landscape lighting is usually low-voltage (12V or 24V) on a step-down transformer, or line-voltage 120/230V depending on the region. If you order a pendant light for the lobby and the ceiling is wired for 277V, it doesn't work, and the return freight is on you.

Then confirm the control. Is it on a dimmer? A photocell? A timer? An occupancy sensor? If it's a dimmer, the fixture and the driver both need to be dimmer-compatible, and the dimmer itself has to match the driver's dimming protocol (0-10V, phase-cut/TRIAC, DALI). I've watched a full row of fixtures get swapped because someone ordered 0-10V dimming into a building running phase-cut. That was a fun week (ugh, again).

Step 2: Size the cable to the load AND the distance

Wire gauge has to be large enough for the load and the run length. Voltage drop is the quiet killer of landscape lighting. On a 12V system, a 50-foot run on 16 AWG feeding three 7W bollards can look fine on paper and still droop at the end of the line.

The NEC informational note in 210.19(A) recommends keeping voltage drop to 3% on a branch circuit and 5% overall, but low-voltage landscape designers usually plan tighter. Basic rule I use: if the run is longer than 50 feet, do the math or ask your supplier to — most of them have a calculator and will run it for you in an afternoon.

Step 3: Check IP and IK ratings against where the fixture actually lives

IP (Ingress Protection) is a two-digit code defined under IEC 60529. First digit is solids, second is water.

IP65 = dust-tight and protected against water jets. IP67 = protected against temporary immersion (1 m for 30 min). IP68 = continuous immersion under specified conditions. The rating is defined under IEC 60529.

If you're specifying bega landscape lighting for a coastal walkway, IP65 is a floor, not a ceiling. Salt air and driving rain are a completely different animal than a bathroom with good ventilation.

IK rating (IEC 62262) is impact resistance — useful when someone backs a pickup into the bollard. IK08 handles roughly 5 joules; IK10 is 20 joules. It's not a spec most buyers ask about, and it's the one that decides whether the bollard survives a lawnmower.

Step 4: Verify the driver and where it actually lives (the one most people miss)

The driver converts AC to the DC the LED array needs. In outdoor fixtures it's usually the first thing to fail. Verify three things before you release the PO:

1. Is the driver included or separate? From what I've dealt with, some bega fixtures ship with the driver already in the housing; others don't. Look at the datasheet for the exact model, not the product photo.
2. Where does the driver live? Inside the fixture, in a junction box, or remotely? If it's remote, you need a protected location and you need to order the remote driver separately — and then hope it arrives with the fixtures.
3. Is the driver dimmable with the control you already have? If not, change the driver or change the control. Don't change both at the last minute.

Most buyers focus on fixture price, finish, and lumen output and completely miss the driver. The fixture is the visible thing. The driver is the thing that actually quits.

Here's the part that surprised me: people assume the LED board is what fails. Actually, in outdoor fixtures, the majority of premature failures I've been involved with were driver failures — usually heat or water intrusion at the gland — not the LED itself. The LED may be rated for 50,000 hours, but the driver often isn't.

On one project, our spotlight lamps failed across the board at 14 months. Every single one. Turned out the remote drivers had been mounted in a cabinet that hit 65°C in summer and nobody checked the driver's ambient rating. That was $6,400 and a lot of apologizing (note to self: "driver ambient rating" is now a required field on every lighting PO).

Step 5: Match the terminal block and cable gland to your actual cable

Before the installer shows up, confirm the fixture's terminal block can take the cable you're sending. A lot of architectural fixtures max out at 14 AWG per terminal. 12 AWG won't fit, and if the installer forces it, you get a bad connection and a hot spot.

Same on the gland. If the gland is sized for 6–10 mm cable and you send 12 mm, it either won't seal — hello, water ingress — or the installer drills it out, which voids the IP rating. Check the datasheet, not the picture. This is a red flag I've walked into more than once.

Step 6: Connect the wires correctly (or make sure whoever does, does)

This is the part most readers are here for, so here's the sequence I've watched our contractors use, and the checks I do afterward:

Kill the power at the breaker and verify with a tester — not fingers, not a volt stick alone. Test hot-to-neutral and hot-to-ground.

Match wire to wire: black (hot) to black, white (neutral) to white, green or bare copper to ground. On a fixture neutral with a ribbed or ridged jacket, the ribbed side is neutral. On a pendant light, this is the first thing to triple-check — pendant cords are notorious for using non-standard colors.

Strip about 3/8 inch (10 mm) of insulation, not more. Exposed copper outside the connector is a shock hazard and a corrosion point.

Use the right connector for the environment. Wire nuts are fine indoors inside a junction box. Outdoors, use a connector rated for the location — a gel-filled waterproof connector, a lever nut inside a sealed enclosure, or an IP68 gland with the correct torque. Put the connector spec in the PO and in the scope of work. If you leave it open, you get whatever's in the van. Trust me on this one — "whatever's in the van" is what fails in year two.

Torque the terminal screws to the value on the fixture label. Over-tightening strips threads; under-tightening arcs. A $40 torque screwdriver has probably saved us thousands by now.

Strain relief and seal. The gasket goes back on, the gland is tightened, and the cable doesn't pull on the terminals. This is where water gets in, and water is what actually kills drivers.

Step 7: Test, document, and only then sign off

Before the installer leaves, get:

• Continuity on each circuit
• Polarity confirmed, especially on low-voltage runs
• A photo of every connection before the cover goes back on (you will thank yourself)
• A luminaire schedule comparing what was installed against what was ordered
• Driver model and serial number recorded

Then file it. The next time a fixture fails — and one will — you'll know exactly which driver to order and where it lives. The first time I skipped this, I spent three hours on the phone trying to identify a driver from a photo of a metal box. Not doing that again.

One last tip: if your company uses an e-procurement or punch-out catalog, add the driver part number and the gland size as required fields in the item description. It forces the question at the point of order instead of the point of failure. It's the highest-leverage change I've made to our purchasing process, and it's a no-brainer once you see the ordering errors drop. Switching to a punch-out catalog cut our lighting order errors by about 40% in a single year — most of that was caught by a required field, not by anyone getting smarter.

Common mistakes I've watched happen

• The "it's just a pendant light" trap. Indoor is easier, sure. But pendants are the fixture most often ordered with a non-dimmable driver right before the room gets a dimmer. Check compatibility even on indoor jobs.
• Mixing 12V and 24V on the same site. They look identical at the connector and they are not interchangeable. Label the runs.
• Assuming "outdoor" means "coastal." It doesn't. Salt air is its own spec; ask about it in writing.
• Ordering fixtures and drivers on different POs. If they ship separately, they arrive separately, and the installer can't finish. Same PO, every time.
• Skipping the sample. On any order over roughly 10 fixtures, ask for one to arrive early. Connect it. Test it. Then release the rest. I know the lead time hurts — do it anyway.

A note on my sample

My experience is based on roughly 40–50 lighting orders across our facilities — mostly commercial office, warehouse, and exterior landscape. If you're doing high-end residential or theater and set work, your tolerances will be different, and some of this will read as overkill. I've only worked with domestic suppliers, so I can't speak to how these principles hold up for international sourcing. And for anything safety-critical, your local authority having jurisdiction and a licensed electrician have the final word — not a purchasing checklist.