Discussion in 'Landscape Lighting' started by coxlandscaping, Sep 2, 2008.

  1. coxlandscaping

    coxlandscaping LawnSite Member
    Messages: 104

    How are you all doing your wiring are you using 10/2 for your home runs and then going to 12/2. I know some that just use 10/2 or 8/2 on really long runs anything else they use 12/2 only just curious.

  2. INTEGRA Bespoke Lighting

    INTEGRA Bespoke Lighting LawnSite Platinum Member
    Messages: 4,102

    Nathan, each sytem and each circuit stands on its own as to how the wiring is done. You have to design and build the circuits to fit the job. As such, there is no hard and fast rule that I apply. Sometimes 12/2 does the job just fine, other times 8/2 home runs are in order.

    You are going to get a lot of different answers to this question based on the transformer technology that is used out there. Here we are limited to UL1838 approved transformers (nothing over 15v) so we tend to used more transformers spaced evenly across the system then others. This also keeps our wire runs down in length but up in terms of number of circuits.

    Have a great day
  3. coxlandscaping

    coxlandscaping LawnSite Member
    Messages: 104

    I know thus far 12/2 has worked just fine for me. I was just wondering if I was missing something with some of these guys using 10/2 for there home runs. I would like to know also when lighting a column do you like to go with something with a spread of say 24deg. or narrow it down even more.
  4. klkanders

    klkanders LawnSite Senior Member
    from Midwest
    Messages: 849

    Nathan, The 24 deg. spread is a good choice however it depends on height of column, width and wattage of lamp. Bring a few extra lamps and experiment til you get the right look.

  5. Chris J

    Chris J LawnSite Silver Member
    Messages: 2,843

    Look at it like this: if you had five lights (145w total) that were 100' away from the transformer, 12/2 would do the job but you'd be pushing your luck. If the customer wanted to add lights later, you would be up a creek cause you'd have to run another wire out there (Big PITA). However, if you used 10/2 as your home run you would have a little room for growth. You could also run two 12/2 home runs for those five lights, but 100' of 10/2 is cheaper than 200' of 12/2. Every situation is different, so you have to accomodate the big picture. The voltage at the electrical outlet will also play a big part in designing your systems. I've seen voltage from 105v-125v coming out of the outlet. This would translate into a difference of 2 volts output at your secondary circuits. 105 at the outlet means your 12v tap will only produce 10.5v. 125 at the outlet, and you've got 12.5v at the taps. Of course these numbers will vary depending on the type of transformers you use, but you get the idea.
  6. David Gretzmier

    David Gretzmier LawnSite Gold Member
    Messages: 3,645

    I agree with everything Chris and James said. I use mostly 12 guage, but pull out the 10 for longer runs and even 8 on rare occaisons. Always build in a light or two head room for increase in wattages or the ability to add a light here and there.
  7. The Lighting Geek

    The Lighting Geek LawnSite Senior Member
    Messages: 886

    i have not purchased any 10 gauge for 4 years, and that was a very unusual situation. I have never used 8 gauge. Like most have already said, with proper planning and know how, you can do almost any job with 12 gauge.
  8. coxlandscaping

    coxlandscaping LawnSite Member
    Messages: 104

    Well do you all take let say a Vista 2216 that comes with a 20w bulb but can handle a 50w bulb max. Let say you have 10 of them do you take 10 x 50w bulb max = 500w to size your transformer.
  9. Chris J

    Chris J LawnSite Silver Member
    Messages: 2,843

    You have to add up the wattage for every fixture and limit your runs to no more than 300w per circuit on most transformers. You can have 2, 5, or 8 runs coming into a single common, but the limit on wattage is 300 per circuit in most cases.
    Having said that, other transformers don't divide the wattage per circuit like this; enter Unique transformers. Their trannys are EI trannys, and the whole load can be balanced across the entire system. Man, I really can't explain all this in writing. Just freakin call me and I'll give you the skinny (The phone call will be $100 payable by credit card).
  10. David Gretzmier

    David Gretzmier LawnSite Gold Member
    Messages: 3,645

    I don't build in 30 watts to spare on each fixture. I build in 30-40 watts per home run, and 100 watts plus on any given tranny.

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