Calculating Voltage Drop, Low Voltage Outdoor Wiring & Overload Conditions

I have a Malibu 600 W (300 X 2) tranformer for my 12 V landscaping lighting. One side of the transformer has 3X20 W lights over 140 ft, on a 12 gauge wire which is working well. The other side has two divisions after a 125 foot run with 2X50W on one limb over 50 ft. Second limb has 5X20W over 75 ft. The lights on both limbs are dim. Please suggest some options to address this. Thanks

This is a classic case of voltage drop! I don't recommend running more than 100' with 120-watts on a 12/2 cable for this vary reason.

You can run another 12/3 or even better a 10/2 cable cable and split the lights into more home runs or connect the cables into a continous loop system. In other words, feed the lights from both ends. You just need to be careful not to cross the polarity of the wires and short circuit the system. This will boost the power and balance out the lighting levels. If that doesn't work, you can always use a HIGH OUTPUT TRANSFORMER to boost the voltage and solve the problem.

You might take a look at our CALCULATING VOLTAGE DROP INFORMATION page for more ideas on the subject.

Labels: Low Voltage Applications, Outdoor Wiring, Voltage Calculation

posted by xinger @ 10:01 PM