Vista 900w multitap

Discussion in 'Landscape Lighting' started by mrossirr, Oct 23, 2006.

  1. mrossirr

    mrossirr LawnSite Member
    Posts: 27

    I have an irrigation customer that is having trouble with his lighting system. Has been in for about 3 years. He says the lights will run for a couple of hours then all 3 breakers will trip. Also says the transformer gets hot to the touch. Transformer was replaced about 6 months ago. Any ideas ? Thanks in advance.
    Mike
     
  2. YardPro

    YardPro LawnSite Gold Member
    Posts: 3,563

    is it plugged directly into an outlet, or does it have an extension cord running to it?
     
  3. mrossirr

    mrossirr LawnSite Member
    Posts: 27

    It is plugged directly into an outlet.
     
  4. High Performance Lighting

    High Performance Lighting LawnSite Senior Member
    from So Cal
    Posts: 326

    Amp probe the commons of each individual 300 watt fuse protected circuit. Your amperage should not exceed 25 amps an each of the three individual circuits.
     
  5. extlights

    extlights LawnSite Senior Member
    Posts: 439

    Seems odd that it takes a couple of hours before the breakers trip. Not only that....but all 3 of the breakers. It could possibly be an overload, but I've never personally seen it happen where the system will stay on that long and then have all 3 breakers trip at the same time.

    Do you happen to know how many total fixtures are in this system and what the total wattage might be?
     
  6. NightScenes

    NightScenes LawnSite Silver Member
    Posts: 2,209

    It sounds like someone has replaced lamps with higher wattages. Not so many that it trips right away, but it takes a while. I have seen this many times. I don't think that all 3 breakers are tripping at the very same time. As stated earlier, check the amperage on all of the commons on each circuit. I would bet that they are pulling around 29 amps on each circuit.
     
  7. High Performance Lighting

    High Performance Lighting LawnSite Senior Member
    from So Cal
    Posts: 326

    I meant to say breaker and not fuse.
     
  8. mrossirr

    mrossirr LawnSite Member
    Posts: 27

    How do I check the amps on all of the common circuits ?
     
  9. NightScenes

    NightScenes LawnSite Silver Member
    Posts: 2,209

    Get an amp meter. Put it around each of the common leads on the secondaries for each circuit. On a 900w transformer there are 3 circuits and 3 commons. Start on circuit/common #1 and check each of the wires coming into it and add the measurements together. The total should be less than 25. If the wire is #12, non of the leads should exceed 16 amps. If the wire is #10, they should not exceed 25 amps. So, if you have 2 #12 wires in common #1 and 1 of them has 15 amps and the second one has 12 amps, you have a overloaded circuit. It would take a while for the breaker to trip though because it's so close to the limits.
    Check it out and let us know what you come up with.
     
  10. High Performance Lighting

    High Performance Lighting LawnSite Senior Member
    from So Cal
    Posts: 326

    For clarity the Vista/Justin 900w transformer has 2 common taps per circuit. Place your amp probe around all of the wires connected to both commons of each individual circuit. It will give you an amperage reading (load) without having to do the math.
     

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