In a straight-line daisy chain wiring layout the calculation of voltage drop along the run is simple to calculate (Total circuit wattage times total length of run to last fixture, divided by the cable constant for the wire size). This formula will give you the voltage drop at the last fixture. My question now, is how do you calculate the voltage drop when you have "T" configuration instead of the straight-line daisy chain? I've attached a couple of diagrams to show the different approaches. The black box with a T on it is my planned transformer location. The green squares are my planned fixtures. The top number beside each fixture is the distance from the previous point and the bottom number is the cumulative distance from the transformer. Appreciate your help.
Hey Dean, The voltage drop formulas can become quite complex and can ultimately over-complicate working with low-voltage LED - the science behind the variables isn't explicitly agreed on across the board either. Ultimately, a voltmeter is the most ideal tool when it comes to verifying voltage ranges during installation and future troubleshooting. On a side note, looking at your chart, we typically recommend low-voltage runs up to a max of 300 feet. There is some slight wiggle room to this given the wider input voltage ranges of LEDs, but typically anything after this is where you can and will more than likely begin to experience a variety of voltage related issues. At ranges of 400-500 feet, we'd likely advise you to consider - 1.) Relocating the transformer if possible to minimize the range 2.) Installing a second transformer in the furthest area/garden bed 3.) Use a few line-voltage fixtures (120V) in the areas furthest away from your house
