Frying down power installation of a building/flat

[akinrog]

There was a thread related to this topic but I would be damned if I could find it. Maybe it was the victim of I-defense incident.

Maybe this is kewlish but as far as I remember that thread contained info how to destroy power installation of a building. It was referring to special (improvised) devices to be plugged in power outlets inside the building and when time comes, it trips and destroys the power system. But I cannot find it. :mad:

Hypotetically speaking if circumstances arises, is it possible to fry down power system of a flat supplying electricity (I'm not sure but either from a arc welder's output, i.e. low voltage high amperage, or an improvised HV device, i.e. high voltage, low amperage).

I think it's possible to do the job by means of an arc welder's output to be applied building side terminals of the circuit breakers after tripping them off (i.e. switching them off), thereby cutting the power from the grid to protect AC current from destroying arc welder.

What do you think about such a thing? Regards.

[inventorgp]

Hmm...

Cutting the cables.

Break the breakers - Hello Mr Hammer.

Short the system, screwdriver. Use earplugs and welders gloves.

Short the grid, by means of throwing cable over the power lines.

EMP? How much are you willing to spend?

Explosives in the electrical box.

Or shaped charges attached to a transformer (grid).


I don't think HV will kill mechanical devises (power meters) but,
it might kill electronic breakers.

And if you have the standard (Aus) 240VAC 10A socket, it hurts a bit:p

[akinrog]

Hmm...

Cutting .........

What I'm trying to do is to stealthily destroy/damage the appliances connected to the building's / flat's power installation. Since I am depriving sleep for a long time, I misphrased what I'm intending to express.

Nowadays, almost all appliances are closed circuit (i.e. they are always connected and energized) thanks to push buttons. Consider your ATX computer, it's always energized, your TV set it's always energized.

Since I'm ignorant of the English terms for which I'm researching, my google searches yield nothing :mad:

Actually what I'm doing is an attempt to convert probably kewlish discourse into something good.

Majority of the meter and circuit breaker boxes are located outside the flat which can be easily accessed.

May be a large capacitor bank and a spark gap trigger geared to live and neutral lines after the circuit breakers are the way to go. There will be minimal electrocution possibility (from the 220 / 110 V power grid) since before the attack you shall turn off circuit breakers thereby cutting the power supplied from main grid to building/flat. (But as for the electroction possibility from the improvised device it is very likely :eek: .)

Since you are cutting the power it's essential that the building / flat is vacant. Otherwise the plan shall be total failure since the occupants shall simply come out for determining cause of the power failure.

[Jacks Complete]

Not sure of your aim here, but I think if you want to interupt power, doing it intermittently is the best way to do it.

Any building that has a RCD protection will trip out with just 30mA flowing to earth (or, indeed, a mismatch of 30mA between live 'in' and neutral 'out'). Take a standard plug adapter, and wire it so that you have a switching intermittent earth fault. Use a resistor to limit the current so our device survives, and a capacitor to soak up the 30mA then spit it out again, and you are set. Just plug it into any socket, and let it randomly trip the power out. Use a 555 timer on a long delay for best effect - the higher than recommended pairs get really flaky, time-wise, so you should be able to guess at 24+/-8 hours, or something. Since the circuit resets a bit each time the power goes off, it will take ages for anyone to spot a pattern, unlike if it was at 6pm every day.

Another way would be to rig something like a big generator into the power line, and fire it up set to 230/240V (Euro voltage) rather than the limp 120V US system. Should cause some issues.

If you want to kill computers, the best thing to do is a brown-out, which is where the power doesn't fail completely, it just drops in voltage. This is a bit harder to do, but wobbling the voltage up and down so the lights dim right down, then bringing it back up a few times a bit randomly but quite fast, will frag any PCs without UPSs. For best effect, do it again about 3 minutes in, roughly when scandisk is checking the host drive for errors if it came back on.

The other best is to connect a mains lead to the network switch or network cable. It will fry a few network cards at least when you toggle the power. Only the very best devices will survive. Even modems, which are designed to live (or at least mitigate) a lightning strike often leave a motherboard doing odd things. As far as I know, network cards don't have any protection from that.

[Chris The Great]

If you wanted to kill power, simply have a little plug in, controlled by remote or timer, that shorts out and trips the breaker. Shouldn't cost more than a few bucks, probably nothing if you scrounge. Probably will short together the relay too so it is "stuck" and unable to turn back off, so the breaker will trip again everytime it is reset. It will continue to do so until someone finds and removes the device, or the decive catches fire and burns down the building. Either works...

[Jacks Complete]

The problem with the cheap mechanical timeclocks is they need power to the pins to run. Otherwise they would be perfect. The same with the electronic ones, as far as I know.

I'm fairly sure a custom battery-backed circuit would be required.

[kenneo]

Cut the mains neutral conductor. If it is a single phase 120/240 system, This will effectively bump up the voltage creating a single 240V circuit throughout the system, causing most electronic devices connected to meet their demise. Usually only devices connected to 1 particular HOT LEG though.

Instead of cutting it you could just simply remove it(with gloves) then reconnect it. This would confuse even the most seasoned troublshooter. :eek: .