Lighting Wire
Lighting wire carries low-voltage power from the transformer out to every fixture in a landscape lighting system - the connection that makes the whole layout actually work. Direct-burial rated wire is built to run underground without a conduit, standing up to soil moisture and temperature swings for years. Wire gauge affects how much voltage is lost over distance, which matters more on longer runs or systems with many fixtures. Shop direct-burial lighting wire sized to match your transformer's output and your layout's total run length.
Lighting Wire
A low-voltage lighting system depends on wire just as much as it depends on the transformer or the fixtures themselves — wire is what actually delivers power from one to the other, and undersized or damaged wire can undermine an otherwise well-designed system before the light ever reaches a fixture.
Voltage drop is the concept that matters most when planning a wire run: voltage decreases the farther it travels down a wire, and the amount of drop depends on both the wire's gauge and the total distance from the transformer to the fixture. A thicker wire (a lower gauge number) carries voltage over a longer distance with less loss than a thinner one, which is why longer runs or layouts with many fixtures on a single line typically need a heavier gauge wire than a short run with just a few lights. A fixture at the far end of an undersized run often looks noticeably dimmer than one closer to the transformer, even though both are wired to the same output — that's voltage drop showing up visually.
Direct-burial rated wire is built specifically to be installed underground without conduit, with insulation designed to resist moisture, soil chemicals, and temperature swings over years of buried use. Using wire that isn't rated for direct burial is a common cause of insulation breakdown and eventual short circuits, since standard indoor-rated wire isn't built to handle constant ground contact.
Wire runs from the transformer to each fixture, and how those runs are wired together — one long daisy-chained run versus several shorter runs split across different transformer taps — affects both voltage drop and how evenly a system performs across a large layout. This is worth planning out before installation rather than adjusting after the fact, since re-running buried wire is far more work than getting the layout right the first time.
The Learn HUB has guides for calculating voltage drop, choosing the right wire gauge for a run, and planning wire layouts for Lighting Fixtures powered by a Transformer.
