California Landscape Lighting

How To Do Low Voltage Landscape Lighting

Low voltage systems are safe, economical, and energy efficient with performance comparable to a 120 volt system.. Fixtures are easy to install, and can easily be moved to accommodate plant growth. There is no risk of shock to children or pets if a cable becomes cut. NOTE: A 120 volt system should only be installed by a licensed electrician.

Allow approximately one hour to layout your low voltage lighting system. You may find it helpful to use the “Questions” form found on the sidebar while reading this guideline. Your questions will be answered by our technical experts within one day.

I. Why Light?
It is necessary to first determine what your purpose is for installing landscape lighting. This will help you decide what type of fixtures you’ll need, how many fixtures, and where you’ll need to install them.

A. Safety. Perhaps you have a walkway or path where obstacles such as small shrubbery, rocks, steps, or low lying tree branches could be a hazard. You may want to illuminate this area to make it easier for your family and visitors to safely go from point A to point B. This type of job may require pathlights along a walkway, or step lights near railings and steps.

B. Security. If the goal is for security to discourage potential burglars, you may want bullet style fixtures for downlighting near windows or other areas of entry around your home.

C. Aesthetics. Showcasing an attractive aspect of your landscape or lighting up a patio, gazebo, or pool area not only looks beautiful and increases your available hours of enjoyment, but it also increases the value of your property.

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II. Lighting Techniques
Decide what you want to light, and how you want it to look. There are several different techniques to use that will achieve any look you desire.

III. Lamp & Fixture Selections
The proper selection of your lamps and fixtures is essential in achieving the desired effect.

A. Lamps. Light bulbs, or “lamps” as they’re known in the industry, are what creates the effect.

1. MR-16. A 12 volt halogen lamp with a variety of wattages and beam patterns.

a. BAB. 20 watt 40° flood lamp, a wide variety of uses such as uplighting small tree specimens and moonlighting.

b. ESX. 20 watt 12° spot lamp, used for up or down lighting specific objects.

c. FMW. 35 watt 40° flood lamp, used for up or down lighting more mature landscape.

d. FRB. 35 watt 12° spot lamp, used for accenting specific objects requiring higher intensity of lighting.

e. EXN. 50 watt 40° flood lamp, used for full grown, mature trees and highlighting architecture/buildings

f. EXT. 50 watt 13° spot lamp, used for spotlighting flagpoles, or downlighting outdoor cooking areas.

2. PAR-36. A sealed 12 volt incandescent or halogen lamp with a variety of wattages and beam patterns.

a. 25WFL. 25 watt incandescent wide flood lamp, used for uplighting or wall washing.

b. 25NSP. 25 watt incandescent narrow spot, used for uplighting specific objects, or slim type trees.

c. 50WFL. 50 watt incandescent wide flood lamp, used for uplighting, mature trees, or wall washing tall areas.

d. 50NSP. 50 watt incandescent narrow spot, used for uplighting specific larger sized objects.

e. 36H-WF. 36 watt halogen wide flood lamp, a whiter lighter with intensity approximately equal to a 50 watt incandescent, used for uplighting or wall washing.

f. 36H-NS. 36 watt halogen narrow spot, a whiter lighter with intensity approximately equal to a 50 watt incandescent, used for uplighting specific objects.

3. Other. Other types of 12 volt lamps may be used in path or spread light fixtures, such as bayonet base (like those used in automobile head/tail lights), A-19 (12 volt version of the common household bulb), or wedge base.

B. Fixtures. Fixtures come in a variety of shapes (to hold the required lamp) and finishes such as black, bronze or verde green to compliment any landscape style or theme.

IV. Engineering
Once you decide on your layout, where you will be placing your fixtures, and what wattage of lamps you are going to use, you will be able to choose the correct cable and transformer sizes.

A. Cable Selection. Cable selection is critical to a 12 volt system. Improperly sized cable will result in dim lights, especially towards the end of the run. This is called “voltage drop”. Distance of the run and the wattage load on the run will determine the cable gauge/size necessary to avoid too much voltage drop for an efficient running system. Use the charts below to determine proper cable size. NOTE: Total Cable Length refers to each single run from a transformer. Multiple runs are commonly used from a single transformer.

You must use low voltage cable that is manufactured for the purpose of use with outdoor landscape lighting. It is UL listed, insulated, UV protected, with a maximum number of copper strands per gauge.

B. Cable Runs. A “cable run” is a routing of cable from a transformer to your fixtures in a sequence. The four most commonly used layouts are:

1. Standard Run. A simple line of cable running from the transformer to the fixtures.

2. Multiple Runs. Several standard runs going in two or more directions, attached to the same transformer terminals.

3. Loop Run. A single cable run beginning and ending at the transformer terminal creating a loop. Helps reduce voltage drop and produces a more uniform light output. Polarity must be maintained.

4. T-Run. A single run cable of a higher cable gauge extending from the transformer with lower gauged cable branching off the end of the larger cable, forming a “T”.

C. Transformer Selection. A low voltage transformer converts your 120/110 volt household current into the safe, 12 volt needed for your landscape lighting system.

1. Wattage. To choose the correct size transformer, add up the wattage of each lamp that will be connected to that transformer. It is recommended that when choosing your transformer, you allow for possible fixture additions or lamp wattage increases. Approximately 80% usage is a good rule of thumb. For example: Your system has 10 fixtures whose lamp wattages total 250 watts. You should choose at least a 300 watt transformer.

2. Options. There are several controlling methods available.
a. Manual Control. Has a simple on/off switch inside the transformer box. It is most commonly used with an outlet controlled by an interior wall switch.

b. Timer Control. Has a built in timer with a 24 hour clock and 2 on/2 off settings allowing for a completely automatic control.

c. Photocell/Timer Control. Has a built in photocell and timer. The photocell activates the system at sundown, and the timer shuts it off at a programmed time for energy savings - or just allow the photocell to completely control the system. An advantage to this control method is no worrying or adjusting at Daylight Savings Time.

d. Remote Control. Has a built in receiving module to respond to any X-10 PRO controlling unit using your existing house wiring. Can be controlled from inside or outside of your home, including from your car.

V. Installation Guidelines
Installing a 12 volt system is safe and easy to do, but careful and proper installation is imperative to a smooth running system.

A. Laying Cable. You start with placing your cable. Dig a trench at least 6 inches deep from the transformer to each fixture location. Lay the cable inside of the trench. At each fixture location, create a loop of cable (about 2 ft. of cable), for the attachment of the fixture. Leave the trench open.

B. Mounting Fixtures. Fixtures require mounting. Place each fixture at it’s desired location. Attach the fixture to the mounting device.

1. Surface Mounts. These are used for placing fixtures on trees or structures.
2. Ground Mounts. These are “stakes” or “spikes” driven into the ground to support the fixture.

C. Splices. Connect the fixture’s lead wire to the cable run by splicing the wires together.

1. Wire Nuts. To achieve true copper to copper contact of the wiring, use wire nuts with a sealant, and electrical tape to prevent corrosion. NOTE: When stripping back cable jacket, be careful not to inadvertently strip away any copper strands.

2. Connectors. A quick way and easy way of splicing a fixture lead wire to the cable run, connectors are often supplied with the fixture by some manufacturers. These should still be reinforced with sealant and electrical tape.

D. Transformer. If you plan to mount it on an exterior wall, keep in mind that every transformer has a certain amount of “hum” or vibration, and should not be placed on a wall to a bedroom, or other room where this could be distracting or disturbing.

1. Installing. Mount the transformer and plug it in. The transformer should be installed at least 12 inches above the ground. NOTE 1: An electrical outlet cover should always be used at the outlet where your transformer is plugged in when your transformer is installed outdoors. NOTE 2: Photocell/Timer control transformers must be mounted outdoors.

2. Connections. Connect all of your cable runs to the transformer terminals. Be sure that cable is stripped back far enough to allow for proper connection, and that all connections are tight.

3. Final Testing. Turn the transformer on to insure that the system is functioning. Once you are satisfied with the fixture locations, and all lights are working, fill in your trench, and wait for the night!

VI. Shopping Checklist

[  ] Cable
[  ] Wire Nuts
[  ] Sealant
[  ] Electrical Tape

[  ] Transformer(s)
[  ] Electrical Outlet Covers
[  ] Remote Controllers