500' Ditch for Low Voltage Lighting

Discussion in 'Landscape Lighting' started by steveprichard, May 10, 2008.

  1. steveprichard

    steveprichard LawnSite Member
    Posts: 9

    Anyone have any tips for cutting a ditch WITHOUT using a walk behind ditcher? I've thought about using an edger or a single tine tiller, but wanted to ask you pros first. I would appreciate any advice you guys might have.
    steve
     
  2. Pro-Scapes

    Pro-Scapes LawnSite Platinum Member
    Posts: 4,181

    What gauge wire are you planning to use and what is your lamp load ? Do you know what kind of voltage you will loose at 500' ?

    You fail to mention what the terrain is like. If it was a lawn I would bite the bullet and use a spade or a vibe plow. By the time you set up the vibe plow tho and repaired anything you damaged you could of just done it the old fashioned way and slit trench it.

    Chances are at 500' we would be adding line voltage closer to the area we needed to light.
     
  3. steveprichard

    steveprichard LawnSite Member
    Posts: 9

    Thanks for the reply.
    I'm coming off of (2) 600W transformers and adding (15) 20W wall wash fixtures to an existing system that I put in last year. One transformer is by the front door and the other is at the back wall. I don't plan on going over 300 feet with either circuit and splitting the lights as needed. And I'm using 12gauge wire. But the ditch will be a total of 500 feet.
    Here in Odessa, Tx., we have a lot of cliche and I know I have that for the top 12 inches but I plan on going only 6 inches or so deep.
    I think I know what a vibe plow is, but what is a slit trench?
     

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  4. Pro-Scapes

    Pro-Scapes LawnSite Platinum Member
    Posts: 4,181

    Slit trech equals spade.... Kick....lift....tuck wires... good luck on the Cliche. If its that bad forget the vibe plow.

    12 ga that far with that kind of load ? Ouch.... how high does your voltage on your trans go ? Do you know how to calculate voltage drop? If your careful you could do 3 runs of 12ga if you have about a 20v tap. Your looking about a 7.5- 8v loss. Thats just aproximate assuming 300ft at 100w load. Much better off either running heavier wire or placing line voltage closer to the area you intend to illuminate.
     
  5. NightScenes

    NightScenes LawnSite Silver Member
    Posts: 2,207

    I would at least be using #10 wire for those runs with those loads. If you use 12 and then have to add a light later you will end up having to run another line. I'm in central Texas which is also very rocky and we just do everything by hand. I have used a concrete saw before though on a ground that was as hard as a rock and it worked pretty well.
     
  6. Pro-Scapes

    Pro-Scapes LawnSite Platinum Member
    Posts: 4,181

    I gotta agree,,,, 10ga is an absoute minimum for what I would use here. I would really push for a line voltage drop someplace closer tho. If its really not feesible to add line voltage then 3 drops of 10 or even 8ga. All depends on how high your trans goes.
     
  7. David Gretzmier

    David Gretzmier LawnSite Gold Member
    Posts: 3,645

    most charts I looked at don't reccomend a greater load of 35 watts at 300 ft using 12 guage or 60 watts at 10. at that wattage load, you can do it, but only if you have taps at around 15 volts. even then you gotta be careful on what voltage/wattage is at fixture 1 on that run verses fixture 3. 35 watts on 12 guage doesn't even get you 2 fixtures in most cases. be careful.
     
  8. Lite4

    Lite4 LawnSite Gold Member
    Posts: 3,109

    Go to a 24 volt system.
     
  9. Pro-Scapes

    Pro-Scapes LawnSite Platinum Member
    Posts: 4,181

    the 24v system would be great in this situation but since he had planned to run 12ga already and didnt seem concearned about the drop I didnt want to toss a 24v system into the works. 24v does have some potential in the right hands. No offence to the original posted but im not certain of the qualifications.

    Joey will pop in tmrw and drop the ball on 24v or just using a 22v tap.

    I still preffer closer line voltage in this scenario.
     
  10. steveprichard

    steveprichard LawnSite Member
    Posts: 9

    Sounds like what you guys are telling me is that the Hampton Bay 600W transformers won't do what they say they will. Are you saying they won't handle 600 watts of lights?
    I think I can design it so that my longest run will be 150' with 6 20W lights and use 10 gauge wire.
     

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