Have any of you experienced this?

Discussion in 'Landscape Lighting' started by Lite4, Apr 16, 2013.

  1. Lite4

    Lite4 LawnSite Gold Member
    Messages: 3,187

    I'm doing some troubleshooting on a project of mine from last fall. Everytime it rains the GFI receptacle trips. The GFI is located on a wall of a covered entryway inside a weather tight "in-use" enclosure (so there is no rain on it). The plug my transformer is plugged into is a standard outlet with an in use cover also and is down stream from the GFI along with some can lights on the home as well as the lamp pole in the yard. The outlet and wiring to the receptacle I am using for my transformer is new and they did not have any tripping problems prior to the lighting being installed. There is a very slight possibility that the irrigation guys may have nicked the wire for the lamp post in the yard, but it is remote at best. I have a 1200 watt Unique transformer that has about 650 watts of load on it.

    So, my question is: Have you guys ever had your secondary (low voltage wiring) have a cut or nick in it that caused a direct short that bypassed the fuse in the transformer and caused the GFI to trip? I don't see how that is possible, but I have had the GFI replaced twice and all of the covers and outlets have been caulked. We are only pulling 5.8 amps on the primary of a 20 amp circuit when fully loaded. Is there anything I am missing? I am nearly 100% confident there are no cuts or nicks in the UF but just wondering some other options to look for or try.

  2. Joey waid

    Joey waid LawnSite Member
    Messages: 109

    Is the gfi rated for 15 or 20 amps. You are pushing the limits with a 15 amp gfi. Also gfi's are really not rated for use with a transformer of that size. A transformer has a lot of inrush current to fill all the windings. A gfi measures out going and in coming current if there not close it will trip. I would look for standing water, in conduit or nicks in the out going power from the gfi. The fuses at the transformer should take care of everything behind it. Gfi's are notorious for flacking out, And its being used for something it was never designed for. Gfi's are usually put in side and branched out. A transformer needs a dedicated circuit supplying it.
  3. Lite4

    Lite4 LawnSite Gold Member
    Messages: 3,187

    20 amp. I am not using the full 1200 watts, only about 600 which shouldn't be a big deal. I have used this configuration for years without issue. There is no standing water and no nicks in the cable "that I know of"
  4. Joey waid

    Joey waid LawnSite Member
    Messages: 109

    Well if it only does it when it rains there has to be a nick. It could have been done during install and just now showing up, there could be a change in the water table or how things drain from then and now. I would try running a extension cord and bypass from gfi to the transformer, try and take as much out of the equation as possible to locate the problem.
  5. Lite4

    Lite4 LawnSite Gold Member
    Messages: 3,187

    Those were my thoughts also, just didn't want to dig up the line if there was something else I could be looking for.
  6. Richie@

    Richie@ LawnSite Member
    Messages: 187

    I agree with Joey , it has to be something down stream causing the GFCI to trip also the new GFCI receptacles for use out side have to be weather resident it will show WR or WR-TP on the face of the receptacle.

    The best thing to do is have an Electrician run a new circuit for your transformer.

  7. bcg

    bcg LawnSite Bronze Member
    from Tx
    Messages: 1,865

    A problem on the secondary side will never cause the GFI on the primary to trip. There is a problem somewhere in the GFI circuit on the primary side. There may be another plug that is on that circuit without an in-use cover or a nick in the wire somewhere.

    This is a good reason to have a dedicated circuit for the low voltage lighting. You don't really "need" it for 650W of load but if you had it, a problem like this would be less likely to happen and far easier to troubleshoot.
  8. INTEGRA Bespoke Lighting

    INTEGRA Bespoke Lighting LawnSite Platinum Member
    Messages: 4,102

    In my experience phantom GFI tripping is usually caused by moisture issues. It may not be a nick in the jacket, it could be a situation where moisture was introduced to the inside of the outer jacket at either end and has now travelled up the wire and is causing the issue.

    Try a gfi breaker instead, as they seem more stable and less likely to trip or no reason. I have always had a disdain for GFI recpticles and usually spec. In a new GFI breaker when I can.
  9. Joey waid

    Joey waid LawnSite Member
    Messages: 109

    This is certainly no place for a gfi. I always run dedicated circuits to all my outside installs. Water will get in to almost everything at some point and time. A gfi is made to trip for the most minor of current changes, I hate them.
  10. Lite4

    Lite4 LawnSite Gold Member
    Messages: 3,187

    Thanks for the input guys. I think I will have the GFI pulled and a new breaker put into the panel to see if that takes care of it.

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