How do I calculate voltage drop for outdoor low voltage lighting?

I am currently installing landscape lighting and have done my research. I am using a digital volt meter to determine the exact voltage at any given light. I am clustering my lights to ensure each wire is less than 100ft and powering 100 watts or less. My volt meter tells me I am receiving 11.5 volts without any lights both from the terminals and at the end of the 100ft wire. After connecting 4-20watt fixtures, my first light is showing about 10.5 volts and the last is showing about 10.2 ... does this sound about right? I was thinking I should be seeing 11+volts running 100watts or less on 100ft or less of wire.Thanks for your help!

I would suggest installing a continuous loop system to prevent voltage drop. Low voltage lighting quickly loses voltage and amperage rises on runs over 100 feet. The loop system will help balance the load and supply equal voltage to all lamps on the run. Check out our How To Design A Low Voltage Lighting Systems page or our handy Voltage Calculator for more information.

You can also consider using a TRANSFORMER with higher output taps to boost the voltage and solve your problem.

Labels: Low Voltage Lighting System, Outdoor Transformer, Voltage Drop Calculation

posted by xinger @ 6:02 PM