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Every lighting job and every lighting system are the same, right? Well, not quite. The wiring method used can affect both system performance and, more importantly, the visual outcome (the lighting portrait). We will compare the most common wiring methods below, but before we do that, let's consider the nemesis of wiring any landscape lighting system: voltage drop. VOLTAGE DROP To control voltage drop in low-voltage landscape lighting sys- tems, there are two things to consider. The first is having a multi- tap transformer to compensate for voltage drop by having several higher-voltage taps available. When utilizing a higher-voltage tap at the transformer, the voltage starts out high then drops down to the proper voltage as the power travels through the wire to the fixtures. There is really only one way to confirm that you are getting proper voltage to your light fixtures — by verifying and testing with a digital voltmeter. Second, you need to be able to distribute equal voltage to ev- ery single fixture in your landscape lighting system, and that takes a well-planned wiring method. The only wiring method that can get equal voltage to every fixture is an equalized hub method of wiring. This method requires equal lengths of wire on all fixtures leading to a central connection point (a hub). There are many myths, misconceptions and falsities out there in the common understanding of voltage drop. Even many light- ing manufactures now say that you can "live" with voltage drop. With the advent of LED lamps with a range of 10 to 15 or 18 and even up to 30 volts, you would think "Oh boy, isn't this great? No more voltage drop." Well, this is really doing an injustice to our industry. To explain, take the following example: A truck engine is de- signed to run optimally at 2,200 rpm, but I run my engine at 2,200 rpm, and you run yours at 4,000 rpm. Both engines will work, but my engine (running at 2,200 rpm) may last 200,000 miles or more. The engine running at 4,000 rpm may fail consid- erably sooner. Similarly, LED lamps have an hour rating of 20,000 to 40,000 hours, but not all LED lamps run at their peak perfor- mance. Years of lamp testing reveal that changes in voltage (de- creasing and increasing the voltage) affect the internal electronics and drivers in four ways: 1. Lamps are most affected by heat (the killer of LED lamps). 2. Volt amp changes in the lamps. For example, a 4-watt lamp might pull 6 watts (that's a 50% increase). 3. Color temperature shifting. 4. Lumen output. Now, that being said, all LED lamps have some increase due to the electronic driver. Make sure you use a true RMS amp meter; this will ensure that you do not overload the wire, transformer or fuse. So the goal then is to get 12 volts to all LED lamps. Let's do everything we can to help them live a long happy life. Use a multi- tap transformer — they have been available for more than 20 years; and although we are using smaller-wattage transformers Landscape Lighting: Voltage Drop and Wiring Methods LANDSCAPE DESIGN AND CONSTRUCTION PHOTOS PROVIDED BY UNIQUE LIGHTING SYSTEMS 20 September 2015 Landscape and Irrigation www.landscapeirrigation.com Left: Multi-Tap Transformers help manage voltage drop. Right: Test with a voltmeter to ensure proper voltage to all fixtures.