Wattage, Amperage & Voltage: The Technical Basics Every DIY Landscape Lighting Installer Should Know

If you’re planning to design or upgrade a low-voltage landscape lighting system, understanding a few key electrical terms will save you time, money, and frustration. The trio of wattage, amperage, and voltage defines how well your system performs — and whether your components are safely matched.

At Sun Bright Lighting, we’re committed to helping DIY installers build professional-quality systems with confidence. Let’s break down the essentials.

⚡ 1. What Is Voltage? (And Why Low Voltage Is Best)

Voltage measures electrical pressure. Outdoor lighting systems operate at 12 volts, supplied by a transformer that reduces your home's 120V power.

Low voltage offers:

  • Safer installation

  • Lower energy use

  • Compatibility with LED fixtures

  • Better long-term reliability

But voltage must remain stable throughout the system — otherwise lights may appear dim or inconsistent.

💡 2. What Is Wattage?

Wattage represents how much energy your fixtures consume. It’s also how you calculate the size of your transformer.

LEDs vs. Halogen Wattage:

  • LED fixture: 3W – 7W

  • Halogen fixture: 10W – 35W (often much hotter and less efficient)

Lower wattage fixtures allow you to run more lights on the same transformer while keeping energy bills down.

🔌 3. What Is Amperage?

Amperage is the amount of current flowing through your wires.

The relationship:

Amps = Watts ÷ Voltage

Example:
8W LED at 12V → 8 ÷ 12 = 0.67 amps

Understanding this helps you ensure your wire gauge is appropriate for the total load.

🧵 4. Wire Gauge and Its Electrical Role

If your amperage load is too high for the wire size, you risk:

  • Overheating

  • Voltage drop

  • Dimming lights

  • System failure

Recommended wire sizes:

  • 12-gauge → most common

  • 10-gauge → long runs or high wattage

  • 14-gauge → small runs with few fixtures

Sun Bright Lighting recommends using direct-burial wire rated specifically for outdoor conditions.

🔋 5. Choosing the Correct Transformer

Your transformer must support the entire wattage load of your lighting system.

To calculate transformer size:

  1. Add total wattage of all fixtures

  2. Multiply by 1.25 (extra headroom)

  3. Choose the next transformer size up

Example:
Total fixtures = 80W → 80 × 1.25 = 100W → Choose 120W or 150W transformer

Selecting the right transformer prevents flickering, dimming, and premature component failure.

🌐 6. Matching Components for a Safe, Efficient System

Understanding these electrical basics helps you correctly match:

  • Voltage output of transformers

  • Wattage rating of fixtures

  • Wire gauge

  • System layout

A well-matched system shines brighter, lasts longer, and requires fewer repairs.

🌟 Build a Better Lighting System with Sun Bright Lighting

Knowing wattage, amperage, and voltage puts you in control of your outdoor lighting.
Whether you're installing a few path lights or designing a full estate layout, the right components make all the difference.

💡 Shop transformers, LED bulbs, wiring, and durable outdoor fixtures at SunBrightLighting.com — where quality meets clarity.

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