Hello All, I'm replacing a very old (15 years) big box landscape lighting system in my front yard. On my longest leg off of the 150W transformer I only have three lights- two 3w well lights and one 1w pathway light. The run is 137 feet. The two well lights are imbedded in my lawn and I decided to use the existing wiring that was already in place to save some time trenching. The existing wiring is thick and looks to be the same thickness as the new 12g wire I purchased from Volt. With the three fixtures installed without bulbs, I get a voltage reading of 13.6 at the end of the run. The voltage mid-run at the well lights is 14v and 13.9v. When I install the bulb on the first well light, the light output is not very bright and the voltage at the end of the line drops to 7.6v. I ran a test line from the transformer to check the fixtures with 100 feet of brand new 12g cable. I installed the two well lights at 50 feet and 75 feet. With both bulbs installed, my end voltage was 13.8V and both bulbs were noticeably brighter. My thought is the old big box wire is either bad (internal corrosion through the outer layer?) or a much smaller gauge than it appears to be. I appreciate any other thoughts or ideas you all may have. Thanks a bunch. Mike
Hey Mike, Great job on the troubleshooting - I'd agree with you that it sounds like the older wire may be the issue. Just curious, did you double check the connection of this old wire run at the transformer tap? It could potentially need some tightening. But, if you already did that - it sounds like the wire may indeed be damaged/deteriorated IMO. Trenching is the definitely the most laborious part of installing a system, but fresh, properly installed wiring is really the key to a system that stands the test of time. You can't beat the added peace of mind (especially if you add some clamp-type connectors or hubs into the mix for easy expansion or troubleshooting in the future).
