Striker Lighting
Guide to Voltage Drop in Landscape Lighting
What it is • Why it matters • How to prevent it • Quick math • Troubleshooting
Engineered for Precision. Built to Endure.
1. What Is Voltage Drop?
As electricity travels through a wire, a little voltage is lost to resistance. In 12V systems, that loss can make far-end fixtures look dimmer or warmer.
- Longer distance = more resistance = lower voltage at the fixture.
- Goal: keep delivered voltage consistent across the run.
2. Why Voltage Drop Matters
- Uneven brightness across the landscape.
- Colour shifts and reduced performance of LEDs.
- Shortened lifespan if over- or under-voltage persists.
Target delivered voltage: typically 10.5V–12.5V at each LED fixture.
3. Main Causes of Voltage Drop
| Cause | Description | Example |
|---|---|---|
| Long wire runs | More distance increases resistance and loss. | 150' run can lose 1–2V depending on load/gauge. |
| Undersized wire | Thinner wire has higher resistance. | 16-gauge vs 12-gauge on same run = bigger drop. |
| High total load | Too many fixtures on one circuit. | 15 fixtures chained on one line. |
| Poor layout | Single long daisy-chain dims progressively. | First bright, last dim. |
4. How to Minimise Voltage Drop
Use Proper Wire Gauge
- 12/2: common for medium runs up to ~150 ft.
- 10/2: best for long runs or heavier loads.
- 14/2: short runs or small zones only.
Striker Tip: When unsure, step up a gauge. Thicker wire reduces resistance and evens out brightness.
Balance Your Loads
- Split fixtures into multiple runs/zones from the transformer.
- Keep total VA per run similar for consistent results.
Use Multi-Tap Transformers
- Choose units with 12V–15V taps to compensate for long runs.
- Connect distant zones to higher taps to deliver 12V at the fixtures.
5. Wiring Layouts That Help
Daisy Chain — simplest; most drop.
T-Layout — branch from a trunk line.
Hub (Star) — central junction for even voltage.
Loop — both ends of run return to transformer.
Zones — separate long and short runs.
Smart Control — photocell/timer for consistency.
Pro Pick: The Hub Method shines with LEDs: tidy, balanced, and easy to maintain.
6. Calculating Voltage Drop (Simplified)
Use this quick estimate to plan transformer taps and wire gauge.
Voltage Drop (V) ≈ (Wire Length × Total Load × 2) ÷ (Wire Constant × 1000)
- Wire constants: 12‑ga ≈ 1.588 • 10‑ga ≈ 0.999
- Wire length is one-way; formula multiplies by 2 for round trip.
Example: 100 ft at 100 W on 12‑ga → drop ≈ 1.26 V. Use a 14V tap so far fixtures still see ~12V.
7. Ideal Voltage Range for LEDs
- Best performance typically between 10.5V and 12.5V.
- Measure at the last fixture on each run to confirm.
8. Troubleshooting Uneven Brightness
- Test voltage at transformer, mid-run, and last fixture.
- Split long runs; move distant zones to higher taps.
- Increase wire gauge; fix/replace corroded connectors.
- Verify total VA vs transformer capacity; leave 20–30% headroom.
9. The Striker Advantage
Multi‑tap transformers, premium brass fixtures, and sealed connections for consistent, long‑term performance.
- Commercial-grade, multi‑tap outputs (12–15V) for precise balancing.
- Heavy-duty terminals and hub-friendly wiring accessories.
- IP‑rated, weather-sealed components for Canadian seasons.
Illuminate with Confidence.
Engineered for Precision. Built to Endure. Design out voltage drop with Striker systems that deliver even, beautiful light night after night.
