| A Consumer Guide to Low Voltage Outdoor Lighting
The purpose of this guide is to aid the homeowner in making an informed decision about the acquisition of residential outdoor lighting. The emphasis is on low voltage (12v) systems rather than line voltage (120v) systems. Low voltage systems are more appropriate in residential settings; line voltage systems are better suited to large-scale commercial and institutional applications. The pros and cons of 12v and 120v are summarized as follows: |
| 12 v | 120v |
| flexibility when installing or relocating; cable is only hidden | wire must be buried 18 inches and/or placed in a protective conduit; difficult to move |
| designed for wet locations and operate safely when exposed to moisture | all fixtures and connectors must be absolutely waterproof; shock hazard potential when wet |
| lamps (light bulbs) are small and allow fixtures to be smaller and less obtrusive in the landscape | lamps much larger and require larger fixtures to house them |
| lamps available in low watt type and many beam spreads; more precise lighting effects can be achieved with lower energy costs | higher watt lamps and one or two beam spreads produce inappropriately high light levels; lack of beam control creates glare problems; more expensive to operate |
| can be plugged into existing outdoor receptacles; no need for an electrical contractor in most cases | must always be installed by a licensed electrical contractor; local permits may be required |
| transformer to convert current from 120v to 12v required; voltage drop (dim lights) can occur if improperly engineered and inadequately sized cable used | no transformer required; voltage drop not as critical |
There are technical constraints in the design and installation of low voltage systems that present problems to the inexperienced; it is therefore important that the homeowner be aware of these characteristics of 12v lighting. If these technical considerations are not properly addressed by the do-it-yourself homeowner or ignored by a lighting design and installation company the resulting 12v system will not perform to an acceptable standard. There is at present no uniform standard governing the performance of low voltage outdoor lighting systems. The standards suggested throughout this web site are based on 30 years of experience with low voltage lighting. This experience includes the completion of over 900 outdoor lighting projects since 1985 preceded by 15 years of design and specification of indoor low voltage systems. In addition, much of the currently available equipment has been bench- and field-tested under the guidance of an electrical engineer. Service and repair of systems installed by others as well as long-term maintenance of systems installed to these standards has resulted in a broad database of low voltage lighting system performance and longevity. The data has been accumulated during actual experience in the field, quantification by test equipment and careful record keeping. This web site provides the basic information necessary to determine whether or not a lighting design/install company has the required experience and skills to achieve an aesthetically pleasing and technically correct result at an affordable price.
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