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12V Outdoor Lighting, Planning & Design

Step One: Make a Plan


The primary use for 12V landscape lights are for paths, living spaces, and security. Please remember that this is a general planning guide only, and you should contact a qualified electrician with any questions or for needed clarification. Keeping that in mind:

  1. Think about areas in which added light would enhance safety, such as steps or a wall around the side of your home.
  2. Think about how you use the property. Are there areas you would like to illuminate for work, recreation or entertaining?
  3. Pick favorite trees, interesting plants, fountains, statues or other attractive architectural elements.
  4. These items will be the focus of your lighting plan.

Step Two: Prepare Your Equipment

  1. Low Voltage Systems
  2. Most residential landscape lighting is done with 12-volt distribution. The system consists of a central transformer, weatherproof cable and low voltage fixtures and accessories.

  3. Landscape Lighting Fixtures
  4. Decide on what landscape lighting fixtures you will be using as part of your complete lighting plan. Choose styles you like and follow the manufacturer's recommendation for the appropriate wattage for the application; if you find the illumination too bright, you may lower the wattage, but never exceed the manufacturer's recommendation.

  5. Transformers
  6. Transformers convert your 120-volt household current to 12-volt DC. Outdoor transformers can be installed on the side of your house and plug into an exterior outlet. They must mount at least 12" above the ground. Higher wattage transformers are actually multiple circuits in one transformer. For example, our 600 watt transformers and 900 Watt transformers are 2x300 watt and 3x300 watt circuits respectively. This allows you to run a higher number of lights for one installation while using only a single transformer.

  7. Cable
  8. 12-volt fixtures take power from a weatherproof, flexible 2-wire cable that can be used above or below ground and generally does not need to be housed in conduit or buried as deep as 120-volt wiring. 12 AWG cable is the minimum gauge recommended for LED installations. Measure the distance from the last fixture on the run to the transformer to calculate the amount of cable needed. Add 1-2 feet of cable per fixture to allow for re-positioning.

Step Three: Wiring Your System and Voltage Drop

  1. Cable Fixture and Layout
  2. If your lighting plan requires more than one transformer, you will need to divide the fixtures into groups or zones. To do so, consider the many areas of your property and how they are used. You may want all of the front yard lighting on one transformer, patio and deck lighting on another transformer, etc. The location of your electrical outlets will also help you to determine how to group the fixtures.

    Maximum Cable Length Per Total Fixture Watts/VA
    Cable Size 50w/VA 75w/VA 100w/VA 150w/VA 200w/VA 250w/VA 300w/VA
    12/2 300' 200' 150' 100' 75' 60'
    10/2 475' 318' 240' 160' 120' 100' 80'
    8/2 750' 506' 380' 250' 190' 150' 125'

  3. Voltage Drop
Excessive voltage drop occurs when too much wattage is placed on a cable that is too long or too small for the load. Voltage drop causes lamps furthest from the transformer to be dimmer than those near the transformer.

  1. Loop Installation
  2. Here, fixtures are arranged in a loop, reducing voltage drop. It is essential that cable polarity be maintained in the installation. Polarity means one wire will be positive, the other, negative, if the wires meet you can get a short circuit which may cause fire or equipment damage.

  3. Straight Run Installation
  4. Fixtures run in sequence directly from the transformer, again, the one farthest from the transformer may experience dimmer lighting due to voltage drop.

  5. Split Load Installation
  6. With a Split Load installation, fixtures run in two or more directions from transformer. Locate the transformer in the center of the run and connect wires to the transformer as you would when using straight run installation. This has the benefit of potentially lowering voltage drop.

  7. Hub Installation
  8. With a Hub installation, fixtures in a group are connected at a central hub. The voltage drop will be virtually identical for each fixture, which makes this installation option optimal for even lighting. Fewer connections are needed, simplifying troubleshooting and system servicing.

  9. “T” Installation
  10. A “T” installation allows more equal distribution of power to the center of the run, or to the run some distance away. If lengthy runs are needed, use 8 or 10 AWG cable to split. Use 12 AWG cable to cross the “T” between fixtures.

Step Four: Consider Accessories

  1. Photocells
  2. Photocells turn the lighting on when the sun goes down. You can combine a photocell (on) and a timer (off) to avoid wasting energy after the household has retired for the night.

  3. Timers
  4. Timers provide automatic on/off control, according to how you program them and can be used in conjunction with photocells.

  5. Lenses
  6. Hinkley lenses are available for use with spotlights to create directional beams of light, diffuse lamp beam spread, enhance color and to reduce overall glare.

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