How to choose a transformer for low-voltage landscape lighting

Start with the lighting plan

A transformer should be selected for the lighting system it will supply. Begin with a list of fixtures, the rated wattage of each fixture and the number required. Include every lamp that may operate at the same time. A system with ten 3 W path lights and two 6 W spotlights has a connected lighting load of 42 W before any additional equipment is considered.

Match the electrical requirements

Low-voltage products are not automatically interchangeable. Confirm the fixture’s specified input voltage and whether it requires AC or DC. A light designed for 12 V AC should be paired with an appropriate supply. Review the selected transformer’s output rating, circuit limitations and operating requirements rather than relying on the product name alone.

The supply should have suitable capacity for the actual load and the manufacturer’s recommended operating margin. Planned future fixtures also matter. Avoid assuming that every model can be operated continuously at its headline wattage under all conditions.

Consider the cable layout

The distance between transformer and fixtures, cable size, number of branches and the distribution of the load all affect performance. Longer or more heavily loaded cable runs can create voltage drop. A larger transformer rating alone does not solve a cable-sizing problem.

For a project with multiple lighting areas, document each branch separately. Note the cable length, connected load and fixture requirements. This makes it easier to discuss suitable transformers and wiring arrangements with a qualified installer.

Choose controls that suit the use

Depending on the model, a transformer may offer timer settings, photo-sensor operation or other controls. Think about whether the installation should operate dusk to dawn, follow a fixed schedule or serve different seasonal needs. Ask for the exact control functions of the model you are ordering.

Before confirming an order

• Confirm input supply, output voltage and AC/DC compatibility.
• List total connected load and any planned future additions.
• Review intended mounting location and environmental exposure.
• Check the required controls and model-specific documentation.
• Confirm cable and connector compatibility with the installation plan.

Our team can help identify catalog options for discussion. Final electrical design and installation should follow the selected products’ documentation and applicable local requirements.