Transformer Sizing in Landscape Lighting: Why It Matters
What Does a Landscape Lighting Transformer Do?
In a low-voltage lighting system, the transformer is the power supply. It steps down your home’s 120V current to 12V (or slightly higher) so your fixtures can run safely and efficiently.
But it’s more than just a power converter — it’s the heart of the system, and if it’s undersized or misconfigured, your entire lighting layout suffers.
Why Transformer Sizing Is Critical
Your transformer needs to handle the total wattage (VA) of your system — plus extra capacity to prevent overload, manage future expansion, and maintain consistent voltage to every fixture.
When a transformer is too small, problems show up fast:
Dim or flickering lights
Early fixture burnout
Overheated equipment
Breakers tripping or power loss
Entire zones failing over time
Unfortunately, most budget installers cut corners by using the bare minimum transformer size, leaving no margin for safety, growth, or balanced voltage.
How We Size Transformers at Ecotek
At Ecotek, we don’t just “match wattage” — we engineer systems for long-term performance. That starts with giving your transformer room to breathe.
Our Sizing Process Includes:
Total VA calculation across all fixtures
Wire gauge and run length (to account for voltage drop)
Future expansion buffer (we often leave 25–50% headroom)
Multi-tap transformer configuration for precise voltage delivery
Load balancing across multiple commons and taps
We’d rather slightly oversize your transformer and ensure stability than max it out and create a system that fails in 6 months.
Read Our Article on Voltage Drop
Read About our Maintenance Plan
Multi-Tap Transformers: What They Are and Why They Matter
Basic transformers output a single 12V circuit. Pro-grade models (which we use) offer multi-tap outputs like 12V, 13V, 14V, 15V, and even 18V — which lets us adjust voltage based on wire length and load.
For example:
A short run might use 12V
A long run with 150 ft of wire might use 15V
A heavily loaded branch might need a 14V tap to compensate
This is how we balance voltage across the entire system — ensuring that your farthest light is just as bright and stable as the first.
Why Bigger Is Often Better
Using a larger transformer doesn’t “waste” power — it ensures your system runs efficiently without strain. Oversized transformers:
Run cooler
Extend fixture lifespan
Allow for future zones or upgrades
Prevent voltage drop from causing dimming or burnout
We’ve seen too many installs where another company maxed out a 150W or 300W transformer, then patched on extra zones later. The result? Flickering lights, failed connections, and unhappy customers.
Signs Your Transformer Might Be Undersized
Lights dim or flicker, especially far from the power source
Transformer runs hot or makes humming noise
Lights get progressively dimmer over time
Breakers trip or transformer shuts down
New fixtures added and old ones stopped working properly
Want a Lighting System That’s Engineered to Last?
At Ecotek, we calculate your transformer size based on facts — not guesswork. Whether you're lighting a small front yard or a multi-zone estate, we build in the right capacity, flexibility, and control from day one.
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No Corners Cut. No Undersized Systems. No Shortcuts.
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