Last updated: 2023-02-11

Low Voltage Outdoor Landscape Lighting Components

Table of Contents

Low Voltage Transformer - Low voltage systems require the use of a transformer to reduce standard 120-VOLT power from your home to 12-VOLTS.
Direct burial Low Voltage Wire - This is two conductor wire designed for connection to + and - terminals on transformer, and connect to lights. The two wires from light fixture have no polarity choice. Does'nt matter which wire is which.
Wiring Methods - Optimum layout and parallel wiring.
Light Fixtures - Fixture/Bulb combinations, create different light output, with different affects.
Wire Connectors - Quick connectors that come with fixtures are of week design, and should be upgraded for a robust install.

picture of landscape lights transformer, wire, lights

Low Voltage Transformer

Low voltage systems require the use of a transformer to reduce standard 120-VOLT power from your home to 12-VOLTS.

Indoor Or Outdoor Mounting.

Most light kits that include a transformer, include and indoor mount transformer.
Indoor transformer can't get wet, and is not going to detect dusk/dawn for auto on/off reliably if at all.

It is strongly recommended to buy and adequate transformer separately, one that is even over rated.

Why buy an outdoor transformer?

Outdoor transformers are easier to mount and more robust.
Get a transformer that uses a remote photo eye. This will be attached to a wire, several feet in length which gives flexibility. Photo Eye also called photo cell detects light. Allows automatic on at dusk, off at dawn.

Considerations For Transformer Location

Choose a location which will be above and away from as much snow and rain as possible. Most common locations are in the garage, on a post, under the roof eve. Garage mounting requires a hole drilled for wire cable entry. An outdoor shed with power available can be an ideal location. Lights location is a consideration for transformer location. - The transformer needs an 120v AC outlet to plug into.
- The transformer needs to be mounted above ground at least 12". Higher if outdoors and where snow may pile up.
- If a photocell is mounted to the transformer, the photocell needs to see light level changes.
- Landscape light wire will run between the transformer and fixtures.
If no outdoor receptacle is present, transformer can be mounted in garage or inside. Light wire and photo cell wire will need be routed outside through the wall.
This is easier than it sounds in most cases.

Power output rating in watts.

- Choose Transformer Size
Transformer size rating is power output measured in watts.

Add together the wattage of your individual lights
Multiply that total by 1.5
The new total is a safe transformer size, in watts. Any upgrades aside. Add future lights! Plan Ahead? Yes. Keep in mind, much of the it is more convenient to add a second transformer. Wire runs to separate areas is planning that keeps a lighting job more simple and expandable

Features to look for in transformer selection.

The transformer below is typical of modern low voltage power supply's (transformer with features). A useful feature is the remote photo cell. The photo cell is attached to a 60 inch wire which makes it easier to place for better sensing light/dark.
Amazon Reviews:

Low Voltage Landscape Lighting Wire

Direct Burial, Two conductor wire designed for connection to + and - terminals on transformer, and connect to lights. The two wires from light fixture have no polarity choice. Does'nt matter which wire is which.

Direct burial low voltage landscape wire.

Flat-Twin Bare COPPER Wire connects in transformer and supplies power to the lighting fixtures. The wire is rated according to the size of its conductors. Selecting the proper size wire is one of the most important aspects of the lighting plan.
The wire from the transformer needs to connect to the wires at the light fixtures. These connections can be made in several ways that involve any of various connector types.

Wire Size

Voltage Drop and Wiring Size

Voltage drop not the issue it used to be when using LED for light source.
The wire size used can affect system performance.

Voltage Drop

Power loss occurs from watts used by lights, some loss is from wire resistance. Power loss on the wire; Voltage drops as wattage increases.
image showing voltage drop on wire with load

Light Fixtures

Light Fixtures / LED Bulbs (lamps)

These are, of course, the producers of light. They get their power from the transformer. Each lighting fixture contains a light source - either an integrated (built-in) LED source or a replaceable lamp (bulb). The lamp could be the older incandescent (usually halogen) type or it could be an LED lamp. The voltage supplied to the fixtures is critical and we will discuss that later.

Light Fixture and Lamp Output Selection

Lots of lighting fixtures are available for outdoor low voltage installs. Most of the low cost fixtures work very well.
Typical install includes a combination of up lights, flood lights, path and area lights. We use LEDs for all our install and repair. 5 to 7 watt LED replaces a 50 watt MR16 halogen, and even brighter. The newer LED retrofit lamps are available in warm, cool, daylight etc. They are available in all the regular beam angles. Even the newer 5 watt LEDs seem brighter than a 50 watt halogen.
We typically spend between $15 and $25 per fixture which comes with a halogen lamp bulb. LED replacements are $5 to $10. Well worth tossing the halogens that come with the fixture.

Low Cost 50 Watt Fixture

Well made sturdy fixtures!! Quality materials used.

20 watt MR16 Halogen Bulb Included
My company replaces the halogen bulbs with LED. LED equivalent is available in all light colors and and beam angles. Typical 7 watt LED is brighter than the 50 watt halogen, and voltage drop is far less an issue. Using the retrofit LED gives better overall light output, as voltage drop is on average, reduced by about 7 times.
Low voltage flood light fixtures are a great option for landscape lighting
High-efficiency lens focuses light
Corrosion-resistant, die-cast metal with a black matte finish

LED Light Source

LED vs Incandescent, Halogen?

A typical 250 watt halogen install becomes 50 - 65 watts with LED.

Retrofit LED Replacements Are Available for ALL New And Existing Incandescent / Halogen Fixtures

LED equivalent uses 7 times less watts on average for same or better light output
LED choices of warm white (~3000 kelvins) to daylight (~6000 kelvins) are easy to find when ordering online
LED has greater life expectancy (with proper connections)

Wire Connections Makes The Difference!

We do not use the quick connectors that come with most fixtures. The quick connectors don't make a perfect connect, and allow moisture into the wire. Poor and decaying connection GREATLY decrease bulb life for any kind of bulb.
Cut the quick connect off and use outdoor rated wire nuts or connectors.

The best WaterProof connector (not just the wire-nut filled with Gel). the problem with the wire-nut filled with gel is not completely waterproof and there is high chance it get corroded over a period of time.This one is perfect for protecting from water and corrosion when you bury it. It comes with the wire nut that you can connect up-to 3 #14 or 2 -3 #12 AUG wires and then secure with the Waterproof gel tube by pushing all the way down and close the lid.This is pretty amazing and will continue to by this product and highly recommend this. Initial connections take a little more time, but saves big in light longevity. Bulbs fail faster when connection begin to fail (even LED). Time to replace corroded wire connections is a pain. Do it right the first time, you won't regret it!

Best Quick Connectors

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