When voltage at the beginning of a length of cable (at the transformer) is higher than the voltage at the end, the difference is known as ?EUR??,,????'??voltage drop,?EUR??,,????'?? and can be a problem on a large lighting installation project unless the proper calculations are made in advance.

Voltage drop can plague a landscape contractor when he is trying to install low-voltage landscape lighting. It?EUR??,,????'???s pretty easy to tell when the voltage has dropped, but figuring how to fix it can be another story.

When voltage at the beginning of a length of cable (at the transformer) is higher than the voltage at the end, the difference is known as ?EUR??,,????'??voltage drop.?EUR??,,????'?? The visual indicator of voltage drop is a dim light fixture at the end of a cable run. The closer the light fixtures are to the transformer, the higher the voltage and brightness. Voltage drop can be minimized through proper selection of the cable size based on total wattage load and the length of run.

The professional lighting installer is always going to provide more diversity to a project than any program can, but the Wire Wizard can ensure that voltage drop will not be a problem, leaving the finished product as vibrant as possible.

Voltage drop should not be below five percent at the load source. To find the proper wire size one needs to know the type of conductor (copper or aluminum), the distance in feet, and the amps needed for the load.

Vista professional outdoor lighting has created a ?EUR??,,????'??Wire Wizard?EUR??,,????'?? on their website www.vistapro.com, where installers can go to find answers to their voltage drop troubles. It is a free tool that is fairly simple to use that gives both the novice and the seasoned professional valuable assistance in the layout of wire and voltage.

 

There are other conditions that will change the voltage drop such as soil type (sand, wet, clay), which affects temperature, or whether the wire is in metal (dry conditions) or plastic conduit (wet conditions).

?EUR??,,????'??We included this on our site as a free tool to help anyone involved in low-voltage lighting,?EUR??,,????'?? said Vista Vice President Tony Cunado. ?EUR??,,????'??The addition of the Wizard has made it easy for any individual with access to the Internet a clear and effective format to lay out a job.?EUR??,,????'??

There are other conditions that will change the voltage drop such as sandy, wet, or clay soils, affecting temperature, or if the wire is in metal (dry conditions) or plastic conduit (wet conditions).

Voltage drop can be minimized through proper selection of the cable size based on total wattage load and the length of run. Voltage drop should not be below five percent at the load source. For instance, 11-volt tap is used when the cable length is less than 60 ft. or the total lamp wattage load is less than 40 percent of the transformer rating.

?EUR??,,????'??The use of the Wire Wizard can help simplify a sometimes daunting task of formulas and division to a few keystrokes on a computer,?EUR??,,????'?? Cunado said. ?EUR??,,????'??The ability to change what was entered so easily makes alternative formats a snap.?EUR??,,????'??

To navigate the Wire Wizard properly you enter the total watts and length of wire for each zone; then the Wizard will calculate the wire size, volt tap, the recommended transformer and the total wire needed.

?EUR??,,????'??The addition of the running wire totals on the chart assist in purchasing and quoting as well,?EUR??,,????'?? Cunado explained. ?EUR??,,????'??They help to identify what wire is needed and how much of each.?EUR??,,????'??

The correct size wire is needed to safely handle the amount of current expected in a circuit. The AWG (American Wire Gauge) is a measure of wire size. The gauge is the diameter of the wire. Since thicker wire carries more current, as it has less electrical resistance over a given length, it is better for longer distances.

As far as transformers go, Tri-Tap transformers ensure longer lamp life and prevent premature bulb burnout due to power surges or electrical spikes, which are common in neighborhood lines throughout the country. The Tri-Tap also helps eliminate lamp dimness caused by long cable runs. Here?EUR??,,????'???s how it works: Select the Tri-Tap voltage output that works best with the cable length and/or lamp wattage per your calculations. There are three different taps:

• T11-volt tap is used when the cable length is less than 60 ft. or the total lamp wattage load is less than 40 percent of the transformer rating.
• 12-volt tap is used when the cable length is from 60 ft. to 120 ft. or has a load from 40-80 percent of the transformer rating. There are two 12-volt tap positions because this is the most common.
• 13-volt tap is used when the cable length is from 100-200 ft. or the total lamp wattage load is greater than 80 percent of the transformer rating.

Installer Roger Anderson told LCN at the recent Landscape Industry Show in Long Beach, Calif., that he has used the Wizard on several occasions and feels that it has saved him time and frustration.

?EUR??,,????'??It can get frustrating trying to calculate voltage drop,?EUR??,,????'?? he said. ?EUR??,,????'??This is a pretty simple thing to use and it has saved me time by getting me my figures before I even start installation; best of all, it has saved me from a lot of headaches.?EUR??,,????'??

The Wire Wizard does not offer the user a better solution or result; that is the professional installer?EUR??,,????'???s job. The Wizard simply offers a baseline format that will help the lighting installer get the most out of the fixtures and wires specified.

Cunado admits this system is limited, but that is because it is so simple to use. While it is not the be all and end all of wire, it is a good starting point.

?EUR??,,????'??There are installation professionals in our industries that feel it is limited, which is true, but by and large it is well received,?EUR??,,????'?? Cunado said. ?EUR??,,????'??The human factor and the professional?EUR??,,????'???s eye is always going to provide more diversity in a project, and the Wizard is good for a baseline format.?EUR??,,????'??

The Wire Wizard can be accessed via Vista?EUR??,,????'???s website, where the user needs to enter a few simple calculations and the recommended wire size, volt tap, transformer and the total wire needed will all be calculated.

?EUR??,,????'??The limitations the Wizard displays are based almost entirely in its simplicity. The Wizard does not offer different format options and suggestions to better a result. It is not the authoritative source for all things wire; that is what the professional installer is on site for.?EUR??,,????'??