The Desert Advocate - Real Estate

Editor | Links | Contact Us | Home

Classifieds | News | Events

Courtesy Photo

Lighting Fixtures
(Click pictures for full size images)

Dear Craig:

I recently had a lighting system installed in my front yard. The system was a high‑end type with a 600‑watt transformer and 12 brass light fixtures. Three of them are fairly bright but the rest are so dim that I have to place my hand under the unit to see if they are working at all. What did I do wrong with the installation?

JP in Phoenix

Dear JP:

Several things may be affecting your lighting system. First, check the transformer to make sure that the output is at least 12 volts. Many of the new, high‑end transformers have several outputs,

ranging from 12‑17 volts, to compensate for voltage drop.

Voltage drop occurs when wire runs exceed one hundred linear feet. Compile this with many fixtures, and you may have a system that is consuming all the voltage.

Typically, I would install light systems with runs of more than 100 feet using 10‑gauge wire for at least the first 100 feet.

Another option is the use of hubs. Utilizing this method, a main line of wire is run to a designated point. Distribution wire of a lesser size, 12‑gauge or 14‑gauge, is run from the hub to the light fixtures.

You may have placed too many light fixtures with the total wattage amounts demanding more than the transformer can provide. A good rule of thumb is to install no more than 75 percent of the actual transformer wattage with all the combined fixtures. The remaining twenty five percent will be consumed in voltage drop and connector voltage loss.

Many of the new, top‑of‑the‑line fixtures are rated higher and include higher‑powered halogen lights. They demand more wattage than generic lights. Typically, they include 35‑50 watts for spots and floods, and 20‑35 watts for path lights. Be sure to calculate the maximum wattage use prior to installing.

I like to install low‑voltage lighting systems using the hub method, with a good quality transformer that allows an upgrade in voltages. This way I can test the voltage at the end of the line, or the hub, prior to distribution of fixtures. I try to install single runs, of more than 100 feet, with 10‑gauge wire then reduce the wire to 12‑gauge for the last 20 feet of each fixture.

Other problems with lighting systems that may cause dimness are shorts in the wire or connections. This can be difficult to find, but generally they occur at the connection points. Finally, there are the old‑style transformers. They can be large, 600 watts, but the wattage is divided into dual, 300‑watt transformers. Sometimes this can be deceiving, especially when you install long runs with one single‑wire pair.

Typically, high‑end light fixtures will contain brighter, higher‑watt halogen bulbs than low‑end products.

· High‑end averages

· Path lights, 20‑35 watts

· Up lights or spots, 35‑75 watts

· Low‑end averages

· Path lights, 11‑18 watts

· Up lights or spots, 20 watts

If you have landscape or garden questions you would like answered email your questions to AskCraig@carefreegardens.net or fax your questions to Carefree Gardens “ask Craig” at 623‑742‑7216. Past articles can be found at www.carefreegardens.net.

Back To Real Estate