It's a Gecko love, a Gecko

April 2, 2012 7:09 PM

Could a gecko really trip the breakers in an electrical mains box?

We recently have been having problems with the breakers flipping while we aren't here (in an office with possibly dodgy wiring). The box with the breakers is inside. The electrician who called in to see us claims that the breakers switching is due to small Australian lizards running across them.

The breakers haven't flipped while we are here with 5 computers, 3 aircons, a fridge and occasionally a coffee machine and toaster going though. Only when no one is here and these mischievous creatures are running wild. To be fair we are in tropical Cairns Australia, and there are indeed many geckos. None of us have observed this gecko electrical sabotage before however.

The business owner dealing with the electrician is a woman and we wonder how much was actual fact and how much colourful Australian blokey bullshit.

His basic claim was - the wiring is ok, but all the electrical leakage from our (turned off) devices plus gecko activities was tripping the breakers. Is this yahoo true blue or trying to pull the wool over our eyes?

posted by gomichild to home & garden (12 answers total)

In tropical-ish Florida lizards would trip things, but we'd find their fried corpses.

My vote goes with maybe. And get a second opinion from an electrician you trust more, because like dentistry, you need to trust the guy you depend on for such weighty stuff.
posted by bilabial at 7:21 PM on April 2, 2012

Hmmm yes we've not found any crispy corpses actually. Interesting.
posted by gomichild at 7:26 PM on April 2, 2012

Unless there is a crispy critter on the breaker, or in the bottom of the box, I doubt it. Seal the box, and the space behind it (difficult probably - the little buggers don't need much room to slip though), and you will have your answer.

On the face of it, unless there are external power surges coming through after hours, it has to be something independent of the power wiring as such. Rats in the ceiling? carpet snakes? Have a look up there and see what signs of intruders are found.
posted by GeeEmm at 7:27 PM on April 2, 2012

Wait, wait. Is he suggesting that a gecko can exert enough force to trip a standard circuit breaker switch, just with its body weight? I know Qld has some big lizards, but surely the ones small enough to run across the breakers aren't that heavy.

Current leakage protection switches (residual-current devices) are a different kind of breaker from the standard circuit overload switch (overcurrent devices). I can imagine that a gecko could run across a circuit board and the stray current could flip an RCD without leaving a trace (dead gecko or strange appliance behavior), but it doesn't sound like that's what you're describing. If the gecko created a short circuit in the wiring in the box/wall, or in an operating appliance, which is what it would take to trip an overcurrent breaker, I would expect charred, possibly burning gecko corpses.

One way or another, it's no good if you can't tell when your sparky's taking the piss.
posted by gingerest at 7:53 PM on April 2, 2012

His basic claim was - the wiring is ok, but all the electrical leakage from our (turned off) devices plus gecko activities was tripping the breakers. Is this yahoo true blue or trying to pull the wool over our eyes?

Breakers can go bad, so replacing them wouldn't be a crazy idea.

That said, they trip when something draws too much current, and a short through a lizard body would do that - my father the electrician finds dead rats this way with some frequency.

But where these shorts are occurring is the question - there will be evidence, and you should be finding it. It's no good if you can't find the fault. If the wiring is in fact dodgy, make sure you've got some marshmallows on hand.
posted by Pogo_Fuzzybutt at 8:11 PM on April 2, 2012

"The electrician who called in to see us claims that the breakers switching is due to small Australian lizards running across them."

Tripping them by running across the breakers? Almost certainly bullshit. Try tripping them yourself, and you'll see how much force they need.

Tripping them by getting between the active and neutral somewhere (in the back of the box / powerpoint / etc)? Happens occasionally. I've actually opened the box, disturbed them, and seen the flash as they get zapped.

An interesting observation : Native Australian geckos will tend to get zapped, die, and you'll find their charred little corpse still hanging there or fallen directly below. Asian house geckos get zapped more often (or maybe they're just more common), but they tend to just get their foot or leg blown off and survive long enough to run away.

One other possibility: Poor local earthing can lead to devices with motors - fridges, air con, etc - tripping the RCD when they're the main part of the load (i.e. at night when the lights and everything else is off), due to the increased impedance of the MEN connection. Even if the earth resistance tests OK at DC (I forget offhand what the AS says - 5Ω? - but there's some leeway there to account for soil type, etc), it can be worth testing the AC impedance. This tends to be a specialised area, though - most residential electricians will give you a blank look if you ask for impedance testing; some that specialise in commercial office installations know how & have the gear to do it; anyone that specialises in commercial industrial installations can almost certainly handle it.

If it's happening almost every night, then it might be worth turning off anything with a motor that starts & stops overnight (or, alternatively, leave all the lights on) and see if that fixes the problem. If so, then I'd suspect earthing issues.
posted by Pinback at 8:54 PM on April 2, 2012 [3 favorites]

Set up a video camera pointing at the breakers, and if you see the little guys running across it and flipping the switches, you have your answer. If not, you will at least see what time they flipped, and may hear if something was going on on the video.
posted by markblasco at 9:13 PM on April 2, 2012

Fellow QLDer here: There is no freaking way a gecko could trip a breaker switch by accident, repeatedly. I'm not sure a gecko could even trip one if it was trying to; you need a bit of force to apply, and with a little thing that wouldn't weigh a hundred grams and no leverage, there's not just way in Hell. He's full of shit.

Also, unless your breakers are seriously dodgy, it shouldn't be zapping the gecko. That's the whole point of breakers - they break. On preview, Pinback is on the money, on all counts. Geckoes may be getting zapped, but not on a breaker, and not tripping it by running across. Arrant nonsense.
posted by smoke at 9:25 PM on April 2, 2012

The only way a lizard or a mouse could trip a breaker by just walking on it would be if the breaker is either bad, or very overloaded. In those cases, the switch of the breaker is very sensitive and can be tripped by a light touch.
posted by gjc at 6:18 AM on April 3, 2012

These tripping breakers - are they over-current protectors (the things that do the job that fuses used to do) or are they residual current detectors (RCDs, safety switches)? It only takes a few milliamps of earth leakage current to trip an RCD, and I would expect a gecko making a path between active and earth to be able to do that and survive if the circuit was protected by an RCD.
posted by flabdablet at 6:30 AM on April 3, 2012

If you're not finding bodies or charred bits, I would suspect that either you have one or more circuits that are loaded to near max and something is coming on when you are away (space heater, refrigerator compressor, air conditioner, dehumidifier, etc.) and tripping the breakers in question, or one or more of your circuit breakers are starting to fail and need to be replaced.

I'm not an electrician, but I am a competent handyman and have added additional circuits to residential and commercial installations, and have replaced more than a few circuit breakers. It is my (anecdotal) experience that the more times a breaker "trips", the "weaker" it will get and be more prone to tripping under less and less load in the future.

Might be a good idea to replace the breakers in question, and if the problem continues, run some tests to see if you can isolate which device is causing the trouble. But yeah, if you don't see any dead lizards or charred bits inside the panel, it's probably either overloaded circuits or old/bad breakers, or a little of both. Appliances with motors (fans, furnaces, air conditioners, blower units, etc.) or compressors (refrigerators, air conditioners, dehumidifiers, freezers, etc) can draw a LOT of current at start-up, and then operate at a mere fraction of their start-up draw.
posted by xedrik at 1:35 PM on April 3, 2012

Thanks everyone - we are getting another guy out to have a look and retest.
posted by gomichild at 3:50 PM on April 3, 2012