Landscape Lighting low voltage outdoor lighting design and installation service since 1974

MAINTENANCE

Every made object has a maintenance component. Precision equipment mounted outdoors delivering controlled and intentional lighting is no exception. In actuality, good quality outdoor lighting equipment has very low maintenance requirements. The reliable operation of lighting equipment indoors or out is a function of lamp life. Since performance, operating cost and maintenance are almost solely a function of lamp type it is worthwhile to describe in detail this aspect of a low voltage system.

"Lamp" Defined
"Lamp" is this guide refers to the capsule that contains a tungsten filament that heats to a white-hot temperature when supplied with 12v current. The temperature of the filament within the hard glass (quartz) capsule filled with a mixture of (halogen) gases determines the quality of the emitted light.

Light Quality
Quartz-halogen sources are characterized by a white light that renders objects lighted in their true, natural color. This is different from the yellow cast of standard incandescent light. Modern automotive headlamps (which operate at 12v) provide this type of white light, and it is even possible to identify an older vehicle at night by the color of the headlamps. The gases in the lamp envelope and the high operating temperature cause the tungsten which evaporates off the filament to re-deposit on the filament, thus extending lamp life; eventually, the filament will break, causing the lamp to fail. Quartz-halogen lamps designed for 12v operation are generally long-lived. Lamp manufacturers publish lamp life data as "average lamp life". This figure is arrived at by burning a number of lamps continuously until half of them fail. Thus, if an array of 1000 identical lamps are simultaneously energized, the time elapsed until 500 lamps "burn out" is the manufacturer's "average lamp life". Note that the lamp manufacturers do not guarantee lamp life, they merely provide estimates of lamp longevity.

Proper Voltage
Since a well-designed 12v lighting system delivers a maximum of 12v and a minimum of 10v to the lamps, one would expect that the quartz-halogen lamps will meet or exceed the manufacturer"s "average lamp life" criteria. This ranges from 2,000 to 10,000 operating hours in theory; in practice, the life of a quartz-halogen lamp depends on operating voltage, manufacturing tolerances and cost: expensive lamps last longer. Cost-benefit factors yield an actual average lamp life of 2,000 to 5,000 hours. Since an outdoor lighting system switched on from dusk to midnight accumulates a total of about 2,000 operating hours annually, lamp life can be accurately assessed. Some lamps will fail "early"; in the example above, 500 lamps failed during the test period to yield "average lamp life" for 1,000 lamps. Lamps operating at less than 12v but more than 10v last longer. Thus, if the voltage at each lamp is known, the failure rate (barring defective lamps) can be predicted.

Lamp Life Warranty
It is reasonable to expect that your outdoor lighting company warrant lamp life for at least two years as part of the original equipment warranty. Since the company that installed the system should know the operating voltage of each lamp, they should bear the risk of premature failure. It is important to know that lamps operating outside the 12v to 10v range will actually have shorter life. A visible variation in lamp-to-lamp brightness is a good indication that a system has not been well designed or properly engineered.

XELOGEN LAMPS ARE THE NEXT STEP IN FILAMENT LAMP EVOLUTION!!!!!!!!!!!!!!

> LAST UP TO 20,000 HOURS

>CAN BE HANDLED WITH BARE HANDS (unlike halogen)

>ARE MUCH MORE TOLERANT WHEN DEALING WITH UNSTABLE VOLTAGES, WHICH RESULTS IN GREATER RELIABILITY AND LONGER LIFE

>XELOGEN LAMPS DON'T EMIT DAMAGING UV RAYS, WHICH MAKE THEM IKEAL FOR HIGHLIGHTING SENSITIVE FAVRICS AND ART WORK

>UNLIKE HALOGEN LAMPS, XELOGENS ARE LOW-PRESSURED WHICH MAKES THEM BURN COOLER AND MAKES THEM MUCH SAFER

>WHEN HALOGEN LAMPS ARE DIMMED, THE LAMP LIFE IS GREATLY REDUCED. DIMMING XELOGEN ACTUALLY INCREASES ITS LIFE UP TO THREE TIMES