Circuit breaking due to Malibu lights

I have always had trouble with my outside Malibu lights ever since I moved in 2 years ago. I finally had them working at some semblance of normalacy last Sunday night. I woke up in the morning and noticed that the ciruit breaker had switched. Apparently the most troublesome outside lights (whose bulbs I just changed and i thought were now working OK) were on the same circuit as a bathroom, laundry room and several indoor fixtures. I tried resetting but the circuit kept breaking. Once I unplugged those Malibu lights the rest of the circuit worked fine. Do you think this is a wiring problem? Do I need an electrician to sort this out?
Thanks Steve
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If the lights work for a while, and then the breaker blows, it can be a number of things. The main thing is to check that there are no shorts in any of the connections, and sockets.
One thing that causes circuit breakers to trip very often is that with age, it may get too sensitive. The fix is to replace the breaker. Another thing that causes breakers to trip, is that there are too many things plugged in to the same circuit, and the breaker is going what it is supposed to do.
If you are not used to dealing with this type of electrical work, you would be safer off to get a professional electrician to service your problem for you.
--

Jerry G.
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Check the breaker that trips. Is it a GFCI breaker? (Ground Fault Circuit Interupter). Does it have a "test" switch? It sounds like it might be if it also connected to the bathroom outlets. If so, it's just doing its job to protect people from getting electrocuted on your property.
It could be tripping because of a ground leakage fault in the Malibu Lights. Most likely this is occuring in the transformer that steps down the 120V to 12 volts or so for the lights. Unplug and check the continuity with a meter, if you can. There should be close to infinite resistance at the plug between hot and ground and neutral and ground. Are you getting a reading other than infinity? Then the transformer ground leakage fault is causing your problem.
This may not necessarily be dangerous. Leakage currents are common on GFCI outdoor circuits. They often cause a condition call nuisance tripping when used with a GFCI. They might occur when the downstream outlets are damp. Often it is difficult to track down the exact source of the problem but I'd put my money on your Malibu Light transformer.
Beachcomber
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Thanks, Do you think it would help to change the whole transformer? I hate the prospect of digging up my malibu wiring and relaying it.
Beachcomber wrote:

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Unless the GFCI is faulty, having a GFCI trip because of a LV lighting system means that something is definately wrong with the transformer itself.
Even if the LV wiring was short circuited/grounded et. al., the GFCI upstream of the transformer will _not_ trip. For a LV fault to trip the GFCI, the transformer would have to have to be faulty too.
It's more likely that it's the outlet or high voltage side of the transformer.
For the GFCI to trip, there must be a leakage current from the neutral or hot to ground. If the transformer is okay, this can only happen on the high voltage side of the transformer, or in the outlet it's connected to.
I'd _tend_ to suggest that the hot side of the transformer or the transformer itself is getting damp, and a conductive path is present to ground. Possibly through the transformer frame. Alternately, the transformer has a coil-case short, and moisture is providing case-ground conductivity.
Alternately, the outlet itself is damp/corroded or gunked up and the transformer is providing the hot-ground path.
Disconnect the unit, bring it indoors, let it dry out thoroughly and clean it. Especially crud around the plug, or where the wires enter the transformer. If the transformer unit is easily opennable (not a plastic molded case), open it up and clean it.
With the power _off_, open up the outlet, check for moisture, corrosion or debris (particularly bug bits). Clean out and dry. Make sure you reassemble the seals properly.
When you put the transformer back outside, try to shelter it from weather, but don't seal it completely, because that will lead to condensation.
Then see what happens. If it still trips, I think you need a new transformer.
--
Chris Lewis, Una confibula non set est
It's not just anyone who gets a Starship Cruiser class named after them.
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Sennin wrote:

* outside Malibu lights * same circuit as a bathroom, laundry room * tried resetting but the circuit kept breaking.
All that adds up to one thing. You have a GFI and it is detecting a fault somewhere.
I would guess if you have a week or two of dry weather, the problems would disappear until you got a good rain.
Start checking all outside outlets including the one powering those lights. I suspect you will find that one has some sort of leak allowing water in. Fix that and you should be OK. It is still possible the breaker - GFI is bad, but in this case my money is on a real ground fault.
--
Joseph Meehan

26 + 6 = 1 It's Irish Math
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