Hi,
About a year ago I bought 5 low voltage pathway lights, each drawing 10w. I hooked them up to a 200w transformer that powers on the lights when it gets dark. Works great, we're very happy with the setup.

I bought a 200w transformer knowing I'd be adding to this when I built a deck. The deck is now approaching completion and I'm adding another 15 10w lights (riser and post lights) to bring me up to 200w. I have plenty of 18/2 ga wire to wire the complete deck but have a couple of questions.

1. The deck wiring will be on 2 different circuits, one for the risers (about 12' from the transformer) and the post wiring which will run the perimeter of the deck - a total of about 50'. The question is - is 18/2 appropriate for the longer distances? Or should I get something like 14/2?

2. The reason I want the riser lights and post lights on separate circuits is like the landscape lights, I want the riser lights to turn on automatically at dusk. For the post lights, however, I'd like them to be powered by a separate switch as while I'll only want them on at night, I don't want them on all the time. I'd rather not have a heavy duty outdoor switch (like I have in other places around the house) - is there something smaller someone could recommend? I was thinking of placing it under the horizontal rail of the rail system so it would be accessible but not stand out. Any suggestions?

Thanks!
Bob

 

Low voltage lights suffer from voltage drop. Smaller cables have more voltage drop than larger cables so the lights will be dimmer the longer the cable. Go with larger cables for longer runs, #10 is commonly used.