Proper Wiring for Longer Runs: How to Wire LED Strip Lights Correctly Over Distance

Introduction

Installing an LED strip for long runs is one of the most common challenges in modern lighting projects. Whether you’re lighting under cabinets, outlining architectural features, or running LEDs across a large commercial space, voltage drop, wire gauge, and power distribution can make or break your installation. Improper wiring leads to dim sections, color shifting, overheating wires, or even premature LED failure.

This guide provides a professional, electrician-approved approach to LED strip wiring for long runs, explaining how to size wire correctly, where to inject power, and why choosing the right cable iis essential for safe, consistent performance

By the end, you’ll understand exactly how to plan, wire, and install LED strip lights over longer distances without brightness loss or reliability issues.

Why Long LED Strip Runs Require Special Wiring

When people begin installing LED strip lights, they often assume the strip itself is the only thing that matters. In reality, the wiring plays an equally critical role—especially over longer distances.

Voltage Drop: The Core Problem

Voltage drop occurs when electrical resistance in the wire causes voltage to decrease over distance. For LED strips, this results in:

• Dimming toward the end of the run

• Uneven brightness

• Color inconsistencies (especially with RGB and RGBW strips)

• Increased strain on the power supply

The longer the wire run, the greater the resistance—and the worse the voltage drop.

Why This Matters for LED Strip Installation

LED strips operate at low voltage (12V or 24V DC). Low-voltage systems are far more sensitive to voltage drop than standard 120V AC wiring. This means wire selection and layout are critical for LED strip wiring over distance.

Understanding Wire Gauge for LED Strip Long Runs

What Is Wire Gauge?

Wire gauge (AWG – American Wire Gauge) determines how much current a wire can safely carry and how much resistance it introduces.
Lower AWG number = thicker wire = less voltage drop.

Why 18AWG Is Ideal for LED Strip Long Runs

For most residential and light commercial projects, 18AWG DC wire offers the best balance between flexibility, capacity, and voltage stability.

✅ Handles higher current loads
✅ Reduces voltage drop over distance
✅ Safe for long power extensions
✅ Easy to route through walls or cabinetry

A proven option is the 18AWG DC Wire (100ft) from HitLights, designed specifically for LED lighting applications and extended runs.

Power Source to Output: Best Wiring Configurations

When planning LED strip wiring for long runs, how you route power matters just as much as the wire itself.

1. End-to-End Wiring (Not Recommended for Long Runs)

This is the most common mistake.

What happens:

• Power enters at one end

• LEDs draw current progressively

• Voltage drops steadily along the strip

Result:
Bright at the start, dim at the end.

2. Power Injection (Best Practice)

Power injection means feeding power to multiple points along the LED strip using parallel wiring.

Benefits:

• Uniform brightness

• Reduced heat buildup

• Longer continuous runs

• Better color accuracy

Common power injection points:

• Every 5m (16.4ft) for 12V strips

• Every 10m (32ft) for 24V strips

Choosing 12V vs 24V LED Strips for Long Runs

12V LED Strips

• Shorter maximum run length

• More voltage drop

• Require more frequent power injection

Best for:
Small projects, tight spaces, short segments

24V LED Strips

• Longer run capability

• Less current draw

• Reduced voltage drop

Best for:
Large rooms, commercial installs, long linear lighting

Calculating Wire Length and Load Correctly

Step 1: Determine Total Wattage

Add up the total wattage of your LED strips.

Example:

• 16.4ft strip at 4.4W/ft = 72W

Step 2: Convert Watts to Amps

Amps = Watts ÷ Voltage

• 72W ÷ 12V = 6A

Step 3: Choose Wire That Can Handle the Load

18AWG DC wire is commonly rated for 10A in low-voltage applications, making it ideal for this scenario.

Common Mistakes in LED Strip Wiring for Long Runs

❌ Using Thin Wire to Save Money

Thin wire causes voltage drop, overheating, and unreliable performance.

❌ Daisy-Chaining Too Many Strips

LED strips are not designed to pass unlimited current downstream.

❌ Ignoring Power Supply Placement

Long wire runs from the power supply increase voltage drop. Place supplies closer when possible.

❌ No Power Injection

Even high-quality LED strips need proper power distribution.

Best Practices for Professional LED Strip Installation

• Always oversize wire rather than undersize

• Use stranded copper wire for flexibility

• Keep DC wire runs as short as possible

• Use parallel wiring for multiple injection points

• Test voltage at the end of the run before final mounting

Safety Considerations for Long LED Wire Runs

Proper wiring isn’t just about brightness—it’s about safety.

• Avoid exceeding wire ampacity

• Use proper connectors or soldered joints

• Secure wires to prevent strain

• Keep DC wiring away from sharp edges

Using thicker wire reduces heat buildup and lowers fire risk, especially in enclosed installations.

Conclusion

Proper wiring is the foundation of any successful LED strip installation, especially for long runs. Voltage drop, wire gauge, and power injection all work together to determine whether your LEDs perform flawlessly or fail prematurely.

By choosing the right approach, and using dependable wiring, you ensure:

✔ Even brightness
✔ Accurate color
✔ Longer LED lifespan
✔ Safe, professional-grade results

If you’re serious about LED strip wiring done right, don’t compromise on the wire; it’s just as important as the lights themselves.